Two small grow lights hang over young seedlings inside of a greenhouse.

Using Grow Lights for Seedlings or Indoor Plants

December 29, 2020 /

Last Updated on February 1, 2024

Grow lights are an incredibly useful tool for growing vegetables, herbs, and flowers from seed indoors. You can also use grow lights to keep houseplants happy and healthy, grow microgreens, or even to provide supplemental light inside a greenhouse. Plants rely on ample bright light to photosynthesize and live, after all. But, where to start? If you’re new to using grow lights, you’ve come to the right place!

This article will provide tips and information about using grow lights for seedlings and other indoor plants, including:

A quick introduction on the benefits of using grow lights, including what types of plants and situations they’re most useful for.
Part One: Considerations for choosing a grow light. We’ll explore the differences between LED and fluorescent lights, along with various ratings to look for like temperature, color, lumens, and size.
Part Two: Best practices and common questions about using grow lights, such as how high to hang them, how many hours to leave them on, and safety considerations.
Part Three: Finally, we’ll highlight a few popular and well-rated grow light options by category, such as “biggest bang for your buck” or the most versatile houseplant light.

By the end, you should have a pretty good idea on how to choose and use the best grow light for your individual set-up and plants! Then once you’re ready to start seeds, be sure to stop by our Seed Starting 101 tutorial for more start-to-finish tips. After all, not having adequate light is one of the top 9 seed-starting mistakes you can make!

Jump straight to popular grow light options here.

Why use a grow light?

Plants rely on light to survive! Through the process of photosynthesis, plants harness energy from sunlight and convert it into chemical energy that is used to fuel their growth. In most cases, the amount of light a plant receives directly correlates to how vigorously it will grow. Using grow lights is an easy and excellent way to provide supplemental light and support plants where adequate natural sunlight is lacking.

Have you seen seedlings that are super tall, or even leaning towards a window? They’re stretching in search of more light. In the seedling world, taller doesn’t mean better! Without sufficient light, veggie seedlings get lanky, thin, and weak (also known as getting “leggy”) and are at risk of flopping over or breaking. Other indoor plants may struggle to grow, produce, or otherwise thrive to their fullest potential without enough light.

One of the best ways to prevent leggy seedlings and grow the most healthy, successful plants is by using grow lights inside. I hate to say it, but more often than not, a bright sunny window alone won’t provide enough light for starting seeds indoors. Especially in the winter months when daylight hours are already scarce; the time most gardeners start seeds for the spring and summer season ahead. The ample light provided by grow lights will keep seedlings short, stocky, and strong. However, bright windows and ambient light are typically sufficient for most houseplants.

Newly sprouted vegetable seedlings in cell packs looking "leggy" underneath a brightly lit fluorescent light. Using grow lights to start healthy seedlings indoors is paramount. — Despite having a grow light over them, these seedlings are already looking a bit tall and leggy. Leggy seedlings aren’t the end of the world, but not ideal. This article has more information about preventing and correcting leggy seedlings.

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Many trays of seedling cell packs with newly sprouted vegetable seedlings are lined up on tables inside of a greenhouse. A few of the seedlings are slightly leggy bust most of them are stocky and healthy from adequate lighting from the sun as well as additional lighting from grow lights. — A few of these seedlings are a tad tall, but far less leggy than the previous photo. An example of healthy seedlings receiving adequate light. This photo was taken in our greenhouse, which doesn’t receive full day sun so we also use supplemental grow lights.

What plants need a grow light?

Certain plants require impeccable bright light for the majority of the day, described as needing “full sun”. Light-loving plants include most flower and vegetable seedlings, warm season annual crops like tomatoes or pepper plants, and hemp. Those guys will all benefit from a grow light while they’re indoors, no matter how naturally bright the space is. Succulents, cacti, microgreens, and herbs also enjoy full sun, but may be grown successfully inside without the use of grow lights as long as they’re near a very sunny window (ideally south-facing if you live in the northern hemisphere).

On the other hand, some plants can get by with lower to moderate light, such as pothos, philodendron, or sansveria – all popular houseplants. Ferns, orchids, and leafy greens can also happily grow in partial shade. Whether or not your houseplants will need a grow light depends on your space. In our home, we’ve found the ambient light from our windows is adequate for most common houseplants. However, plants in darker homes or interior rooms without windows will greatly appreciate a light! See our Houseplant Care 101 guide for more details on low, moderate, and bright light plant types.

Growing something unusual? Do a quick search on that plant’s unique light needs.

A black shelving unit with grow lights built into the top of each shelf is placed against a wall next to a window. Each shelf has various types of seedlings growing underneath two fluorescent bulbs with reflectors above each shelf. The shelving unit contains wheels and allows for adjustable lighting so you can change their height above the seedlings. — These summery tomato, bean, flower, pepper and basil plants all love full sun – and grow lights! This all-in-one LED light shelving unit is from Gardener’s Supply. We recently added one of these to our grow room/barn at the new homestead, and grew the most healthy, robust seedlings EVER!

PART ONE: CHOOSING A GROW LIGHT

Grow lights come in all sorts of shapes, types, and sizes. So much so, that the various choices and number of grow lights on the market can feel overwhelming. Trust me, I get it! We’ve used several styles of grow lights over the years. LED, T5, multi-bulb arrays, single bulbs, with and without reflectors… the list goes on. Each of them has their pros and cons; it all depends on what you intend to use them for. And that’s the very purpose of this article – to help you figure it out!

Which grow light should I buy?

You’ll have to evaluate your unique needs to decide. As you read through the information below, consider the area and type of plants you want to use grow lights for. For example, how much square footage you need the grow light to cover. Will you need multiple lights, or one strong one? Can the style you’re looking at ‘daisy chain’ or connect several lights together? Is there a lot of headroom above your plant to hang a light high? Or, will it need to be kept fairly low, such as over trays of seedlings in between shelves?

The price for grow lights also varies widely, so do whatever fits within your budget. No matter what you choose, providing indoor plants with supplemental light will make them significantly more happy than going without!

Fluorescent vs LED Grow Lights

LED grow lights are all the rage these days! LED, which stands for light emitting diodes, are very efficient, and can also be quite powerful. Yet some old school gardeners swear by their classic fluorescent lights instead.

Note that there are many types of ‘fluorescent’ lights, including compact fluorescent lights (CFLs), basic fluorescent tubes, high-output T5 fluorescent tubes, and more. When it comes to fluorescent grow lights, T5s are considered the best choice for plants. T8 tubes aren’t quite as effective and bright, but are cheaper and can do a decent job for indoors seedlings or lettuce plants.

In general, a standard 45 or 60 watt incandescent light bulb (or LED equivalent) that you’d use in a household lamp fixture will not provide sufficient light for starting seeds or growing other plants that require ample light.

Differences between LED and fluorescents:

LED lights are generally more energy-efficient than fluorescents, and therefore lead to lower electric bills.
LED lights typically have a higher upfront cost than classic fluorescent tube lights, but may have a longer lifespan.
Since they’re made up of dozens of diodes, LED lights come in a wider variety of shapes and sizes. T5 fluorescents are long slender tubes (e.g. “shop lights”) with either one or several tubes mounted in a ballast fixture.
Per watt, LED lights give off more lumens of light. Therefore, a compact LED fixture has the potential to give off stronger light than a comparatively larger T5 fixture (but it depends on each light’s specifications). Some LED lights are weaker than T5s.
It is usually recommended to keep LED grow lights suspended significantly higher above plants (feet) than T5 fluorescent lights, while fluorescents can be kept only inches above plants. This makes fluorescents more ideal for shelving systems with close quarters. Read each light’s specific recommendations!

Two purple and blue LED lights are hanging above a nondescript plant. They are thin in diameter to allow natural lighting in as well as the plants and lights are inside a greenhouse. — LED lights. Note that not all LED lights look colorful like this! Some emit a more natural white light, shown below.

Grow Light Ratings: Temperature, Brightness & More

As you shop for grow lights, you’ll notice various ratings for light temperature, Kelvins, watts, lumens, and more. This topic has the potential to get complicated (and often does), so I’ll try to keep it as simple as possible!

What color grow light should I get?

For growing seedlings indoors, choose a grow light that is described as “full-spectrum” or broad spectrum. I recommend the same for houseplants too. With a full-spectrum light, you’re getting a good balance of both blue and red light – and the closest thing possible to natural sunlight! Makes sense, right?

If you’re really curious to know the difference, cool blue light is great for promoting leafy green foliage but also regulates plant growth, keeping plants short and stocky. This is great for microgreens and seedlings (or plants in the ‘veg’ stage), but too much blue can also lead to stunted plants over time. Warm red light stimulates both vegetative growth and flowering, yet excess red light can make plants tall and lanky. Average household incandescent light bulbs emit mostly warm light, giving off a comfortable and cozy vibe – but not ideal for plants.

If the grow light temperature isn’t stated outright, look for its Kelvin rating. That will tell you the color of light it will emit. A full-spectrum grow light that closely resembles daylight will have a Kelvin rating of 5000 to 6500K. Cooler blue grow lights are rated around 4000 Kelvins, while warm or reddish lamps have even lower ratings – around 3000K. If you can’t find a full-spectrum light in the ideal Kelvin range that also fits your other needs (budget, size, availability, etc) a “cool white” light (4100-4500K) will also work well for germinating vegetable seedlings, growing microgreens, and raising young transplants.

An empty room with grey laminate flooring with the numbers 2000, 3000, 4000, 5000, 6000, and 7000 placed against the far wall. Above each number is the light at which the number rating emits. Showing that the lower number provides a warmer orange light and the higher the number provides a lighter white light. Using grow lights with the correct Kelvin rating for the specific application is helpful to maximize your results. — Kelvin ratings reflect the temperature and tint (warm or cool) of the light. Image courtesy of BG Energy Solutions.

Light Brightness and Lumens

Lumens is a measure of visible light that a source emits. The more lumens, the brighter and more powerful the light is. Vegetable seedlings and other “full sun” plants require about 2000 to 3000 lumens (at minimum) per square foot of growing space. So, if you’re growing just a single standard tray of seedlings, using a grow light that emits 3000 lumens is sufficient. Otherwise, do the math and scale up to a brighter light. Or use multiple light fixtures to provide a good canopy of light over a bigger space.

For example, consider a grow space that is 3 feet by 3 feet, or the equivalent to 9 square feet. Multiplying 9 by 2500 lumens (the average of the adequate range) tells us that a 22,500 lumen light would work well (or several lights that add up to cover that space). If math isn’t your strong suit, don’t worry. Most grow light manufacturers provide specs on the square footage they’re designed to cover.

Finally, keep in mind that wattage doesn’t dictate brightness! As we briefly discussed previously, LED lights give off more lumens per watt, so a low wattage LED (say, 20 watts) may give off even more bright luminous light than a 60 watt incandescent or fluorescent bulb.

This powerful little LED light panel gives off 15,000+ lumens despite it’s low wattage and fairly small footprint (perfect as a supplemental winter light in our greenhouse, allowing plenty of natural light around it). According to the manufacturer, it is rated for a 2 by 2 foot space of flowering plants, or a 3 by 3 area of seedlings/clones. Note that it has to be kept much higher above the plants than T5s.

Size of Grow Light

Consider two variables when it comes to sizing grow lights: the size of the actual light fixture, and the size of surface area it’s rated to adequately illuminate below the grow light. (See the section above about lumens and square footage too). Your growing area, ideal set-up, and number of plants directly influences the size of light that will work for you.

Are you growing trays of microgreens or seedlings on a shelf? Try fluorescent tube lights or strip LEDs suspended from the shelf above. Is there a dark corner in your living room where you’d like to keep a houseplant or two? You could use a single strong LED bulb or a sleek lamp fixture that blends in with your home decor. Panels or boxy light fixtures are ideal in a grow tent, starting seedlings on a table in your garage, or other larger area.

Some grow lights illuminate an area significantly wider than the light fixture itself. Others only adequately support the plants that are directly below the lights. If you aren’t sure, your plants will tell you! Seedlings on the outskirts of the light canopy will often lean inwards towards the brighter light. In that case, you may need a larger light. Or, you’ll need to routinely rotate the seedling trays below the light every day or two so all the plants have equal time in the spotlight.

Also remember that most gardeners pot-up their seedlings from small seed-starting cells to larger containers at least once (sometimes twice) before transplanting them outside. That move to a larger pot size will also increase the space the plants take up under a light! Meaning, you may need larger (or more) lights than you imagine when you first set out planting seeds!

We use grow lights in our partially shaded greenhouse as supplement light, so we opt for compact and slender T5 light fixtures so they won’t block the natural sunlight the greenhouse does receive. For seed starting indoors, I recommend a more full-coverage light style, like the one shown below.

Vegetable seedlings growing in seedling puts underneath a large box style light with T5 bulbs. The seedlings are growing into the light and there isn't too much of a worry of burning plants with fluorescent bulbs. — A more full-coverage boxy grow light style (with several T5 fluorescent tubes) ideal for indoor seed starting.

A tiered wooden shelving unit with various potted succulents and a small glass vase with two water plants growing under water are shown with a clip on houseplant light with two bulbs that can be adjusted with bendable arms to keep plants happy in low light settings. — A sleek spotlight like this is perfect for a handful of houseplants. Be sure to check out my top choice houseplant light in Part Three below!

PART TWO: USING GROW LIGHTS

How high should I hang my light above my plants?

A common question about using grow lights is how high to hang them above plants. The answer is: it depends! Usually, it’s recommended to hang high-output LED lights at least at foot (or higher) over plants. If they are too close, LED lights can and will burn your plants – known as ‘light burn’, and akin to a human sunburn. On the other hand, many fluorescent lights do best when they’re kept only a few inches above the plants.

When in doubt, follow the height recommendations provided by the light manufacturer. If that information isn’t provided, watch your plants for signs! Happy seedlings receiving adequate light will grow straight upwards, and stay fairly short and stocky. Seedlings that are hungry for more light will stretch tall and thin, and/or lean towards the brightest light source. If a light is too close and intense, burned leaves will turn yellow or brown, and sometimes have papery dry brown spots or tips.

In most cases, you’ll want to be able to raise the lights as the plants grow taller. This can be accomplished with an adjustable light chain, pulley system, or good old-fashioned string. Keep that in mind if you’re starting on a shelving unit that is already tight.

Tall vegetable seedlings inside of a greenhouse are shown with T5 grow lights that can be adjusted for height with rope hanging amongst the top of the canopy. The vegetable seedlings will be transplanted outdoors soon but using grow lights helps grow healthy seedlings. — As you’ve seen in other images in this article, fluorescent lights are usually kept fairly low above plants. These huge tomato seedlings had been potted up several times and were just about to be planted out in the garden. We raised the grow lights every week as the plants became taller, and eventually stopped using them all together as part of the hardening off process.

A cannabis plant with burnt and bleached leaf tips from being too close the the light source when using grow lights. — Leaves suffering from light burn; the result of a strong LED light being too close to the plant. Image courtesy of growweedeasy

How long should I leave my grow lights on?

Seeds don’t need light in order to sprout. Steady warm temperature is more important for sprouting, such as that provided via a seedling heat mat. So, you technically don’t need to turn your grow lights on until after they emerge from the soil. However, you’ll want to provide light as soon as possible after germination. Freshly sprouted seedlings have the tendency to get leggy, fast! To play it safe, you could turn on the light a few days after you plant seeds, even if they haven’t popped up yet.

Once sprouted, most vegetable seedlings and other garden plants require at least 12 hours of good light per day, along with 8 hours of darkness. However, seedlings will grow the best when provided 14 to 16 hours of light. Houseplants are happy with less, where 6 to 12 of light is sufficient (depending on the type of plant).

To help keep our light schedule on target, we’ve found it incredibly convenient and useful to add a timer to our grow light set-up! The timer is set to turn the lights on around 6 am and off at 9 pm. You can find a full list of all our favorite seed-starting supplies here.

Tables inside of a greenhouse that are arranged in a U shape along the three sides of the greenhouse have trays of vegetable seedlings growing atop them. The tomatoes and pepper and other light loving plants along one side have grow lights hanging above them to provide additional supplemental light while the plants that can get by with less light such as greens and flowers aren't being provided with additional artificial lighting. — The short days of winter (January-March, when we start our spring and summer seeds) don’t provide enough natural light to the seedlings. So, we use grow lights to extend the hours of light they get – giving priority to heat/sun loving crops like tomatoes, peppers, and eggplants. The leafy greens, herbs, and flowers do okay with the natural daylight in the greenhouse as they become larger and spring draws near, though we keep those under lights for the first few weeks after germination also.

Grow light reflectors

Most grow lights come with built-in reflectors around the bulb fixture, helping to amplify and cast the light downwards. You can also create additional reflectors in your grow space! For example, one of my good friends starts her garden seeds using grow lights in a spare closet. Lining the back and side wall around the seedling trays with tin foil creates a reflective surface that bounces additional light back to the plants. The inside of specialized grow tents are usually lined with a reflective material for the same reason.

Can grow lights hurt my eyes?

The short answer is yes, so don’t stare at them. Any type of extra bright UV light can be damaging to our eyes. Blue light is also known to disrupt brain activity and sleep patterns. Working around colored grow lights can be generally uncomfortable to some folks (as opposed to those that emit white or “natural” looking light). We tried using an LED light that produced a very pink/purple hue one year, and being around the light gave me an instant headache. The plants that year also didn’t look nearly as healthy as they normally do with T5s.

Lettuce plants are growing underneath pink and blue LED lights. — Personally, I can’t stand being around colored lights like this. Even this picture makes me feel ill. Maybe they won’t bother you, but it is something to consider… especially if you’ll be working around the lights a lot or have them in your living space.

Other safety considerations

Always be sure to mount or hang your light in a safe and secure manner that meets the manufacturer’s recommendations. Some grow lights give off heat. In general, LED lights are the least warm, T5 fluorescent tubes are also fairly cool but slightly warmer than LED, while T8 fluorescent, CFLs, or incandescent bulbs heat up the most.

Choose quality, reputable light brands that have good reviews. The light should be UL-listed or certified, meaning it has been tested to meet safety standards for electrical devices. If you’re using grow lights in an area that may be exposed to moisture (e.g. a humid greenhouse or one with ceiling vents), seek out a light that is considered waterproof or otherwise safe to use in that setting, and connect the light to a grounded outlet.

PART THREE: POPULAR GROW LIGHT OPTIONS

Biggest Bang for Your Buck

Several of the customer reviews for this Durolux T5 high output light fixture literally say “the biggest bang for your buck“! I haven’t seen many comparable units at this affordable of a price. With four fluorescent bulbs that emit a combined 20,000 lumens, this four-foot long shop-light style unit provides ample bright full-spectrum light for growing seedlings and more. It would be perfect hung over a table or mounted inside a wire shelving unit, and is equipped to connect several lights together if needed. Despite the strength, you can still keep them as low as 3 to 4 inches above plants without burning.

Looking for something a tad more compact? Check out the shorter two-foot version here.

Buy it here

A box style T5 florescent light with four bulb ballast.

Two box style T5 ballasts hang above vegetable seedlings inside a room on top of plastic tables. Using grow lights indoors is crucial to happy and healthy seedlings.

Most Versatile Houseplant Grow Light

This sleek little LED grow light is ideal for houseplants that could use a boost! It can clamp onto a variety of surfaces (e.g. bookshelf or table) and has 3 swivel heads that move around as needed. The lamp provides a cozy warm-looking light but is indeed full-spectrum, and has 5 different brightness levels to choose from. It also has a built-in timer! This unit is so versatile, it could probably also work for small number of veggie seedlings (especially as supplemental light with a sunny window). The three-light version is shown below, and a smaller two-light option is available as well.

Buy it here

Houseplants sitting on a shelf with a clip on light that contains three bulbs that are arranged to provide light equally throughout the plant canopy.

A two tier image collage, the first image has a pyramid shaped shelving unit with many potted plants on each shelf. There is a clip on houseplant light with three bulbs providing light to each tier of shelf space. The second image shows many potted plants arranged in a corner of a house with a clip on houseplant light providing additional lighting to the plants in a 360 degree direction. Using grow lights in a low light space can provide enough light for some plants.

Best all-in-one set up for serious seed starters

Vermont-based Gardener’s Supply Co has created some awesome all-in-one grow light shelf kits! If you plan to start more than a handful of seedling trays, or have dozens of small potted plants, this could be a great option for you. After all, once you factor in the cost to purchase several quality lights plus a shelving unit, this snazzy 3-Tiered SunLite shelf would just about break even. The unit gets great reviews for being sturdy, mobile, easy-to-use with adjustable lights, and most importantly, effective at providing high quality light. I’ve also seen folks hang additional light over the unit and create a 4th upper shelf! The one shown below is the full-spectrum 6500K T5 fluorescent version.

You could also step it up a notch and go for the ultra-efficient LED version. We recently added this grow light shelf to our grow room/barn at the new homestead, and had the most robust, healthy seedlings we’ve ever grown!

Buy 3-Tier SunLite

Buy the LED version

Seedlings we grew under the LED SunLite shelf, in under 4 weeks!

Best Little Lights for Beginners

If you’re a brand new gardener, only need one modest light or two, or otherwise want to keep things as simple and inexpensive as possible, consider these options. First, check out this two-pack of 2-foot long T5 fluorescent lights. We’ve used the 4-foot long versions, and they’ve held up to many years of use. They aren’t the highest output lights in the world (2500 lumens per two foot bulb), but they’ll do the trick! Their mounting/hanging system is admittedly a bit wonky too. We had to MacGyver that. Another similar (perhaps brighter) option is this two-foot long box light from VivoSun.

Buy it here

A set of two 2 foot high output T5 light fixtures that can be daisy chained together.

If you’re a beginner looking to try LED lights on the other hand, MarsHydro is a really well-known brand. Here is one small and affordable full-spectrum light fixture they offer. It’s rated to light a 2 feet by 2 feet space of veggie seedlings. However, keep in mind you’ll need to hang LEDs much higher over your plant canopy. The one recommends to hang the light about 18 to 24 inches above.

Buy it here

A LED light fixture with attachment cables.

Best overall LEDs for grow tents (& more)

Are you venturing into grow tents, or creating a DIY grow set up in your closet or shed? Horticultural Lighting Group (HLG) Quantum board lights are incredibly well-rated and powerful. The lighting portion of the lights are made by Samsung, and are quite popular with the herb-growing community (if you catch my drift). Yet you can use them for other types of plants and locations too of course! We have this model (shown hanging in our greenhouse earlier in the article), which is rated to adequately light a 3×3′ space of plants in veg, or 2×2′ area while they’re in flower. Note these lights can’t daisy-chain together, but they do have larger options. Another popular brand with similar specs and options to HLG is Spider Farmer.

Buy it here

And that concludes this crash course on using grow lights 101.

Well that was illuminating, now wasn’t it? I hope that this article turned on a few light bulbs in that noggin’ of yours, and helps you plan your grow light set up for the happiest plants possible! I also hope I made this somewhat complex subject nice and easy to understand. Please let me know if you have any questions or feedback in the comments below. Also, please help spread the love and knowledge by sharing or pinning this article. We appreciate you coming to us to learn something new. See you next time!

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Deanna Talerico

Deanna Talerico (aka DeannaCat) is a garden educator and writer with over 15 years experience in organic gardening. She is a retired Senior Environmental Health Specialist, and holds a M.A. in Environmental Studies and B.S. in Sustainability and Natural Resources.

64 Comments

Ema Suarez-Berumen

August 29, 2022 at 11:03 am Reply

Hello,

I am so happy I found your blog and is incredibly helpful, especially for myself that I have just started trying growing plants and have completely no experience whatsoever.

I do have a quick question regarding my Mandevilla and its growlight if you don’t mind answering.

Its growlight is Full Spectrum (natural yellow light) with 420 LED beads and output of 200W. It is set for 12 Hrs (starting at 7:00 AM), it is healthy and keeps on growing, yet it does not produce any flowers.

My question is, what type of grow-light would stimulate flowers without harming them?

Thank you for your time,

Ema
- Aaron (Mr. DeannaCat)
  
  August 29, 2022 at 2:15 pm Reply
  
  Hello Ema, while I am not familiar with Mandevilla in general, it seems that they can be increasing difficult to set blooms indoors. Do you keep the plant indoors year round or do you keep it outdoors during the warmer weather? It may be beneficial to move the plant outdoors through the summer as your plant may bloom during this time, being sure to move it back indoors before temperatures reach the low 50’s F.
  
  There are more high powered LED lights but they can also be hard on your eyes so if the plant is in a part of your house that you are in often, having a high powered LED in the corner of the room is not recommended. I use this grow light indoors to grow cannabis through its whole cycle and it covers a 4×4 foot space and you would likely want to keep the light 14-18 inches above the top of the plant. However, when I am in the room working with the plants, I wear glasses that protect against all types of UV lighting or else you can harm your eyes.
Roy Tada

August 8, 2022 at 7:09 pm Reply

Thanks for all the pot info<,i aslo love to grow aloe vera the thick and wide strain.
Rebekah

April 20, 2022 at 1:30 pm Reply

Deanna,

Thank you for the detailed answer to my google search of ‘why are my plants leggy?’ I feel very fortunate to have found your website and happily subscribed to your newsletter. I have just moved from New Mexico to NW Montana and learned I am not the only one desperately missing the sun!

I visit the tanning beds and now I will purchase grow lights for my seedlings. 🙂

Rebekah
- Aaron (Mr. DeannaCat)
  
  April 20, 2022 at 1:47 pm Reply
  
  We’re glad you found us Rebekah and congratulations on your move, I am sure it will be a learning curve with the different climate and all. But yes, good grow lights will help your seedlings tremendously and will give them a great head start before you harden them off to plant them outdoors. Good luck on getting your garden going and have fun growing!
Nicole

April 5, 2022 at 8:58 pm Reply

I would like to know how to choose a grow light? Which parameters of grow lights should be paid attention to?
- Aaron (Mr. DeannaCat)
  
  April 6, 2022 at 7:44 am Reply
  
  Hi Nicole, I don’t know that we have any exact parameters, it has been more of a trial and error experience. It also depends on what the purpose of the light is. If you just want grow lights for seedlings until they can be transplanted outdoors into your garden, we have had good success with high intensity or high output LED lights that have at least 3 light tubes in each ballast that seem to cover about 3×1.5 foot space. If you are going to be growing a plant from seed to harvest indoors, we would go with a full spectrum LED light. Hope that helps and let us know if you have any other questions.
Blake

April 3, 2022 at 4:38 pm Reply

Hey there,
I knew this would be the place for the info I need 🙂 I’m using LED lights this year for the first time and have been puzzled about my struggling veggie starts. I now know that I have burned my plants somewhat, with the lights too close. Woops. Do you recommend starting over, or can my starts recover?
Thank you!
- Aaron (Mr. DeannaCat)
  
  April 4, 2022 at 8:01 am Reply
  
  Hi Blake, it depends on how small the seedlings are and how burnt they got. If you have a high powered LED light, hopefully the manufacturer has instructions on how high to hang the lights for seedlings. Our high powered LED light that can be used from seed to harvest for full cycle plant growth recommends 24-30 inches above for seedlings and 12-18 inches for full sized plants. In all, you just need to use your best judgement as plants can recover from light burn but it helps if they are more mature seedlings that can handle it. Goods luck!
Claire

March 30, 2022 at 9:30 am Reply

Hello! I have created my own grow light shelves with flourescent bulbs. I have started seeds for my garden and have had a lot of seeds sprout and grow into very healthy, happy plants. But I have had others that sprouted about 3-4 weeks ago and still have their baby leaves. They seem to just have stopped growing. Particularly my brussel sprouts, eggplant, and bell peppers. Any tips as to what may have gone wrong?
- Aaron (Mr. DeannaCat)
  
  March 30, 2022 at 11:52 am Reply
  
  Hello Claire, congrats on building your own seed starting racks, that is exciting! Are all of your eggplant, pepper, and brussels sprout seedlings stunted or just some of them? Eggplant and peppers are notorious slow growers and may take awhile before they start to take off, they may be stunted if conditions are too cold (especially their soil temperature), if they are overwatered, or they are too crowded/don’t have enough root space. The plants may also just be runts or mutants but the chances of that happening are much smaller than what you seem to be experiencing. If you think soil temperature may be an issue you may want to add a heat mat below your seedlings and set it to 70 degrees F or so and that should help their growth accelerate. Hope that helps and reach out if you have any further questions, good luck and have fun growing!
  - Claire
    
    April 3, 2022 at 8:21 am Reply
    
    It may be that they are too cold! I will look into a heat mat. Thank you!
Alicia

March 22, 2022 at 9:31 am Reply

Hello- I am curious to know what distance you use between brand new seedlings and the LED grow light from Gardener’s Supply (vs the T5 flourescents you use). I am new to starting seedlings and have the LED version of the 3 tiered Sunlite. Thanks so much, your website is the best and so helpful!!!
- Aaron (Mr. DeannaCat)
  
  March 22, 2022 at 10:49 am Reply
  
  Hi Alicia, congrats on your seed starting rack. We actually have the high intensity LED 3 tiered Sunlite rack and we keep the lights only 3-4 inches away from the seedlings and we have only seen amazing results. We are growing some of the best seedlings ever using this set up. We haven’t experienced any of our seedlings being scorched by the light, even when they grow into the lights before we have a chance to raise them higher. Hope that helps and good luck on getting your seedlings going!
  - Lisa
    
    April 2, 2022 at 8:35 pm Reply
    
    Can you share more about how you arrived at the 3-4 inches with the Sunlite LED high-intensity lights from Gardener’s? I have the same lights without the shelving unit and being a novice/1st time grow light user, I was at a loss at the distance placement. Gardener’s gives no indication in their instructions, nor were able to provide any specifics because there weren’t any from the manufacturer. I’ve been reading about the caution of having LED lights too close so keeping it away a foot or more would prevent burn…but not all LEDs. What made you decide to go with 3-4 inches? Is there something I can look for that will help me know? Was it just an experiment the first time?
    I love all the stuff you guys share on your blog! So many things I am trying are ideas I got from you. Thanks bunches!
    - DeannaCat
      
      April 3, 2022 at 7:47 am Reply
      
      Hi Lisa – We went with what the most common recommendation for grow lights in general, which is just a few inches above the seedlings. It was a bit of a trial and error too, we kept them nice and low and figured we’d see burned leaves if it was too strong. However, given the way the light shelf is designed (with lights on fairly tightly spaced shelves) we suspected that had to be okay – you can only raise the lights so much there, ya know? Especially as the plants get larger. This is compared to some large intensive square LED light boards that Aaron uses to grow cannabis – in that case, the manufacturer specifically tells folks not to place them any closer than a couple feet from the plants, so he has them suspended from the ceiling of our grow room and the plants on the floor. If there is a risk of burning and/or they should be kept further away, the manufacturer should say. Otherwise, closer is usually better or seedlings will get leggy. I hope that helps! Thanks for reading
Mary Roberts

February 5, 2022 at 9:40 am Reply

Hi there! Thanks for the article, it was exactly what I was looking for. But, if you are willing to help a fellow gardener, I have a couple of questions that I think, based on your website, you may have the perfect combination of expertise to know! 🙂 I just inherited from my father 2 large panel LED lights that have 3 fan outlets on the top. I don’t have any information on them, as he had them for many years and used them in a grow tent to grow cannabis plants seeds to harvest. I am growing vegetable seedlings – tomatoes, eggplants, peppers, etc. In the previous 2 years, I’ve used a single bulb T5 fixture. They work but also kinda drove me crazy with how frequently I had to rig up something to get the light to shine on all my seedlings – without reaching and becoming too leggy. So, this year, I purchased a wire rack with 4-5 adjustable shelves and attached the panel lights from my dad, plus another smaller panel light someone else gave to me (it only has a 2 fan exhaust output). You are right, they are SUPER BRIGHT!! If I do choose to use them, I will have to put a curtain around the shelving unit to block the light from the rest of the room. It is uncomfortable to be around. I am wondering the following: (1) the length of the shelves is about 3 feet long, will the light reach the seedlings on the fringes equally as those directly below? (2) how far away do you recommend the light should be from the seedlings? (3) I’d like to use the LED panels, as they are already mine, but do you think it’s too much for the veggie plants? Should I just revert to using the T5 grow lights? Any advice you offer will be MOST APPRECIATED!! I just don’t know anyone who can advise me on something like this!! Thanks so much for sharing your knowledge. :). ~Mary
- Aaron (Mr. DeannaCat)
  
  February 5, 2022 at 10:06 am Reply
  
  Hello Mary, do you know the brand and or model of the LED lights? If they are high powered LED lights made for full cycle plant growth, they should probably be placed at least 24-30″ above the seedlings. The area the light can cover will be determined by the brand and how big of a panel the LED lights is. Most smaller LED lights can typically cover at least a 2×4 or 3×3 feet of light coverage. The higher powered LED lights may not have enough headspace for your seedlings if you have them on a rack. If you know what the make and model of the light is, it will be easier to find directions on hanging heights for different stages of plant growth . Also, high powered LED lights can be tough on your eyes, they sell sunglasses that block certain rays that the LED lights emit, making it easier to be around the lights when you are working around your plants. Hope that helps and let us know if you have any other questions.
  - Mary Roberts
    
    February 6, 2022 at 2:55 pm Reply
    
    Thank you so much for your quick and helpful reply!! You are so kind to help me
Josh B

January 5, 2022 at 4:36 pm Reply

Greetings! I just recieved a link to this odler post in my email and noticed that just about every recommended light in this review is no longer available! I guess that’s the rub doing business with Amazon. There is no telling if a product is tried and true and will continue to be available a year from its inception on the website, or if it is destined to be gone with the wind six months later. Any thoughts about testing and recommending products from a more reputable source, even Home Depot or Lowes? Despite not having a global reach, they at least cover a broad range of the North American continent.
- Aaron (Mr. DeannaCat)
  
  January 6, 2022 at 8:09 am Reply
  
  Hi Josh, thank you for reading the article, I just double checked all the links in the article and only one of the lights is “unavailable” at the moment. We also have linked Gardener’s Supply Company for multiple lights and they are a good company that we like to support. We haven’t looked into or tried any lights from Home Depot or Lowe’s but it looks like HD carries HLG lights that we recommend in the article. Again, thanks for reading and let us know if you have any other questions.
Peter Boonzaaier

May 7, 2021 at 12:27 pm Reply

Hi
Thank you for a great tutorial. I live in South Africa and recently acquired a grow tent sized 80x80x170cm. I am a total beginner and would love to work with peppers and chilli types. I managed to get a full spectrum grow light
A full-cycle grow light will provide your plants with the blue, red, UV and IR spectrum wavelengths that are needed for optimal growth.

Specifications:

Wattage: 50 Watts
Voltage: 85 to 265Vac 50-60 Hz
LED Colour:
Red 620-630nm
Blue 460-470nm
UV 390-400nm
IR 725-735nm
Coverage: 2sqm at 2-meter height
PAR:
142 mol @ 0.5m
76.4 mol @ 1m
45.8 mol @ 1.5m
40.2 mol @ 2m
Dimensions: 330mm x 30mm

Also i got led bulbs:
Wattage: 9W
Lumens: 900lm
Beam Angle: 150 Degrees
Lifespan: >10,000 Hours
Colour Temperature: Warm White (3000K) or Cool White (6500K)

my question is now that i am starting seeds will this be enough? and if not what do you recommend.
Looking forward to your feedback:)
PS: Did i mention im a student with a very low budget lol
Peter
- Aaron (Mr. DeannaCat)
  
  May 10, 2021 at 2:59 pm Reply
  
  Hi Peter, it seems like you have a couple fairly decent lights to use which should work more than well enough for your chili peppers. Since most grow lights seem to be made for cultivating cannabis, pepper plants should do just fine with them as well. The main learning curve you will have to figure out is how high above your plants to hang your lights so the plants get enough light but not too much where they are burned by them. If you look into the brand of lights you have, there may be recommended light height for seedlings and mature plants. Hope that helps and good luck with your chilis!