Grow Lights Are Essential to Seed Starting Indoors

Your seedlings are dependent on light, but not just any kind of light: good-quality light, and lots of it. This is a piece that I really got wrong when I first started and was reluctant to buy artificial lights. I was convinced my seedlings would be a success in a south-facing windowsill. 

Don’t get me wrong—you can keep a plant alive in a south-facing window. But we need our seedlings to rapidly grow into strong, healthy plants that will thrive in your garden, and overall, you’ll find better and more consistent success with artificial lights. 

Here's the thing: Seedlings grown indoors without artificial light tend to be leggy (or tall and narrow without many leaves). Or they lean over too much because they're looking for sunlight. Or they just grow very slowly. It's rare for seedlings to get enough light to be fully healthy and robust from just sunlight indoors. Seedlings like their light source very close to them.

And before you ask, standard light bulbs that you'd use in a lamp or light fixture don't provide sufficient light for seedlings either.

Let's look at some of the best options for giving seedlings the type of up-close-and-personal light they really want.

What to Look for in Grow Lights for Seed Starting Indoors

If you're shopping around on your own, look for three things that will save you time and energy and keep your seedlings much happier.

Full-Spectrum LED Lights...

The most common types of grow lights you'll find are LED lights and fluorescents. LED lights are super long-lasting and energy efficient compared to fluorescent lights. (If you keep LEDs on for 12 hours a day, you're looking at about $2 in electricity for the month.) LEDs also don't produce that much heat, so you don't have to worry about seedlings getting too warm if they're close to the light source. While LEDs are a little bit more expensive than other types of bulbs, I think they're worth it in the long run.

Full-spectrum is the closest thing to natural sunlight at noon that you can have indoors thanks to their balance of red, white, and blue lights.

... That Are Maneuverable...

Your light source has to be able to be raised and lowered as your seeds sprout and grow. You'll want your light source very close to the seeds as they're just starting to germinate, and then, as the seeds grow, you'll want to be able to raise the light source to give the leaves more room. You can easily maneuver wand lights over your seed starting trays, or you can go with a more formal setup like mine, where your lights hang over your shelves and can be raised and lowered with a chain or pulley system.

...And Come with a Built-In Timer

Look for lights with a timer or remote to simplify your life. All you have to do is program your lights to turn on and off at the same times each day, and then check to make sure the timer is working. Most timers have memory functions that give you the option of turning on for 4, 8, or 12 hours every day. Your seedlings will appreciate the consistency.

Some of the links in this article are Amazon affiliate links, which means I receive a small commission at no extra cost to you if you click on the link and purchase the item. All opinions remain my own.

The Best Seed Starting LED Lights

Here are some of my favorite options when it comes to grow lights for seed starting indoors:

• GooingTop LED Grow Lights ($26.99 for planting clip with 2 full-spectrum lamp heads) - I really like that these can just clip on to the side of a shelf or tabletop (though be warned that these clips can scratch or make little indentions in your furniture). The lights are at the end of flexible goosenecks, so you can basically just maneuver each wand tip right over the trays and control their angle and height. You can even extend two lights over one large tray or split two heads between two separate trays.
• Lxyoug Grow Lights with Adjustable Tripod Stand ($31.44 for 4 full-spectrum lamp heads) - This has 4 lights on the edge of flexible goosenecks. This stays in place thanks to the tripod stand instead of clips, so you won't risk scratching your furniture, but you do need a fair amount of space to set this up next to your trays.
• FRENAN Grow Lights with Adjustable Tripod Floor Stand ($49.99 for 4 red-blue spectrum lamp heads) - This is a similar product to the tripod stand above.
• Burpee Two-Tier Grow Light ($299.99 for the aluminum structure with two shelves, two seed starting trays, and two adjustable growing lights) - This is a smaller version of what I have. The lights suspend above each shelf and can be raised or lowered with the chain pulley system.
• Super Sprouter Deluxe Propagation Kit ($55.56 for a seed starting tray, a humidity dome, and a high-output fluorescent grow light) - This kit is a great option for beginners who aren't looking to start a whole bunch of seeds indoors.

Tips for Starting Seeds Indoors with Grow Lights

Many seeds do not require any light to shine on the soil to germinate. Even so, I begin turning my grow lights on and off from the first day that I plant my seeds, and I recommend you do the same. Otherwise, make sure you're ready to turn on the lights as soon as you see the first sign of green emerge from the soil. Your seedlings will be much healthier if they wake up and feel a little light shining on them. Lower your lights to be just a couple of inches above your seed trays. 

Your lights should be on for 12 to 14 hours a day. Get in the habit of turning your lights on when you wake up and turning them off before you go to sleep (if you're not using a timer). Just as important as turning your lights on each day is turning them off. Remember, we’re imitating nature, so we need to give our plants some time in the dark to simulate night. 

You may be thinking, “But if these plants were outside right now, they probably wouldn’t receive 12, much less 14, hours of sunlight per day,” and that’s especially true the further you are from summer solstice. Just know that time under artificial lights is not the same as actual time under the sun. 

As your seedlings start to grow, you’ll slowly lift the lights higher so that you don’t burn your seedlings. You also want to make sure your seedlings have plenty of space to grow without coming into contact with the lighthead. It's best to leave about 4 inches or so.

Monitor your plants for signs that you're not getting the lighting situation quite right. Seedlings that like their light situation will grow straight up and stay pretty short and full.

Signs your seedlings aren't getting enough light:

• seedlings grow "leggy," meaning their stems are too long and thin (they're stretching toward the light)
• seedlings look pale green or yellow (they're not getting enough light to produce chlorophyll)
• seedlings have long gaps on the stem between leaf nodes
• seedlings drop their leaves
• seedlings are growing too slowly

If you notice any of these signs, either increase the duration that your grow lights are turned on or move your lights closer to the seedlings.

Signs your seedlings are getting too much light:

• seedlings look burnt
• seedling look discolored or have brown tips on leaves (I’ve had leaves turn almost white and get a papery texture when the light was too strong or too close.)

If you notice these signs, try moving the light source further away from the leaves. 

If your light source isn't big enough to cover every single leaf on your tray, make sure to rotate the tray each day so that your seedlings will grow more evenly. Otherwise, those seedlings on the edge will grow leggy and lean toward the light source.

You might find that you need more lights or larger lights than you anticipated, especially if you're growing plants that need a little bit longer time indoors before they can be moved outside. Plants like tomatoes and peppers often need to be potted up to larger containers so their roots don't become stunted in those little cells, and if you're potting up a lot of seedlings, you're going to need more light to cover them all.

Seed Starting Without Grow Lights

If you're not ready to invest in artificial lights, then you'll use free solar light, and by that, I mean the sun. Just know that your seedlings might never be as robust as their friends grown under lights. This is especially true when most of us are starting seeds indoors for the spring and still experiencing shorter days in the winter months.

For that reason, I recommend steering clear of plants that need to spend longer indoors like tomatoes and peppers. Focus on starting herbs for your garden instead.

Find More Indoor Seed Starting Tips and Resources Here at Gardenary

The difference in seedling health that a good set of grow lights can make means they're more than worth the initial investment. Plus, you can use these same lights when you're not starting seeds to grow your own microgreens indoors.

We've got lots more tips waiting for you in our Seed Starting course inside Gardenary 365. Our goal is to help every gardener have the confidence and skills needed to start their own seeds indoors, so we're constantly releasing more resources. (Find our recommendations for seed starting supplies on Amazon.)

Thanks for helping make gardening feel ordinary again, and best of luck to you as you start your seeds!