Grow lights

When I first began researching the best grow lights for indoor gardening, I quickly got lost down an overwhelming information overload, since there are so many products available. With all the features acronyms, and different ads shouting for your attention, it's easy to get confused.

  • What does it all mean?
  • What's actually important?
  • And what can you ignore?

As with anything gardening, it all comes down to what plants need--which is really pretty simple. They need light, and if you want to bring your gardening indoors--or start hearty seedlings indoors--you need to give them a boost of added light. Household lights are basically insufficient--especially if you want to bring the plants to full growth.

As someone living in a northern climate, I’m just not ready to say goodbye to my gardening hobby at the end of every short summer. Grow lights are something that I’m looking into for my own household use to extend my (very short!) growing season.

So here's the skinny.

 Good luck with your grow light shopping.

The best grow light for general gardening use is a full-spectrum LED panel light. For many gardeners’ needs, the best overall light would be the Green Sunshine Electric Sky ES300 V2. This is an LED light that can cover plant needs at all stages of growth. It covers a 2 by 4 foot space for flowering plants, or 5 by 7 foot space for vegetables. This light replicates the sun’s infrared wavelengths, and projects light to give full coverage to a rectangular space. 

Depending on your budget, you may want to check these out, too:

  • For the lower-cost option, something like this BOHON LED grow light would be a great place to start. It’s affordable, easy to assemble and can give off different wavelengths of light to accommodate different growing stages. The flat panel structure makes it easier to provide the right amount of light to all the plants on your tray (no skimping out on those poor guys on the margins!), and the fact that it is LED means that it is more energy efficient and longer lasting. Keep in mind that this is low budget. While 72% of Amazon ratings are positive, longevity is an issue for this light.
  • For a medium budget: You’re ready to invest past the cheapest products, but not wanting to go too deep--this Optic 1 Cob grow light may be what you are looking for. It is not a panel light, but for its size it can cover an impressive 2 x 2 foot space for flowering plants. You could experiment with one light, and if you’re happy with it, you could slowly purchase more of them. The light provides full-spectrum coverage, meaning it’s good for every stage of plant growth, and it comes with a hanger and a six foot power cord.
  • For higher-value, the Black Dog LED PhytoMax2 1000 provides the highest power (1600 LED watts) and boasts the largest coverage available (6.5 x 6.5 feet). It comes with an 8-foot power cord, and a set of 8-foot adjustable light hangers. This light provides the full spectrum, so your plants will get what they need at every stage of growth. At over $2000, this light is an investment for the serious grower.

How to decide the best option for your situation

So how do you figure out the best option for you--and your plants’--specific needs?

Well, there’s a reason that there are lots of products on the market. There are different factors to consider, and there’s a grow light out there that will best suit your situation. What would be ideal for me may not be ideal for you.

So while an LED panel grow light is a great place to start, the real answer to the best grow light is: it depends.

Grow Light Basics 

To be perfectly honest, the idea of buying grow lights is a huge leap for me as a backyard gardener. When I first began to consider it, I had images of my house looking like a garden center, or parting with plenty of money to buy complicated systems I don’t understand.

I’ll say it: I was intimidated.

A bit of research, though, has made me feel equipped to make the leap. It really doesn’t have to be that complicated.

As we all know, plants need light. They need light for the process of photosynthesis--capturing sunlight and turning it into energy to grow. A by-product of photosynthesis is oxygen--take a deep breath and enjoy that fresh air feeling that indoor plants bring!

Supplement natural light & extend the growing season

Grow lights replace sunlight for indoor plants. If you live in a climate like I do, where the first frost warnings appear in September and finally end in June, grow lights are a great way to extend your growing season. You can supply your plants with plenty of warmth and light even when your backyard is buried in snow, and when that summer sunshine finally shows up, you can get a head start with strong, sturdy transplants.

To start seeds indoors, or to grow plants to maturity indoors, you need to think about how you are going to provide your plants with enough light. Putting seedlings in front of a south-facing window will work for a small number of seeds, but if you want to grow a lot of seedlings, or to grow the plants to maturity, it’s not going to be enough.

If, like me, you’d like to bring your gardening indoors to escape a long frigid winter, the weak wintry light streaming into your kitchen is just not enough to support plant life. Even in the case of just a few seedlings, they'll be stronger and healthier if they get additional light.

Except for a few shade-loving houseplants, your plants will require grow lights.

Flowering & fruiting plants, & seed starting

Flowering/fruiting plants, like tomatoes or cucumbers, will require the most light. Vegetables and herbs will require less light. Seedlings grown under the right amount of light will be stronger and make for heartier transplants than their leggy, sun-starved counterparts merely set in front of a window.

I’ve always started seedlings indoors (you kind of have to when frost warnings can appear in mid-June), but to be honest, I haven’t been very happy with them.

This year, they were pretty fragile looking and they didn’t thrive when transplanted to the garden.

Grow lights, as opposed to my dining room window, would help me to grow more robust seedlings. Or, if you want to get really committed, you could cheat the climate altogether and grow plants to full maturity under grow lights, enjoying fresh herbs and crispy lettuce all year-round.

Even tomatoes and lemons can be grown under lights! Hm…. That is a tempting thought.

Different types of grow lights (& their pros & cons)

There are a few basic different types of grow lights, each with their pros and cons:

Standard fluorescent lights

Standard fluorescent bulbs are pretty weak in intensity and need to be placed very close to the plants to have much of an effect.

They can be useful in situations where you just need a little bit of light, for shade-loving plants or to supplement light coming in from a window. You can find fluorescent bulbs that are higher intensity, or advertising “full-spectrum light,” meaning they can support flowering plants. (More on the “full-spectrum” bit later.)

If you're only growing a few plants, fluorescent bulbs may be all that you need.

LED lights

LED lights are more expensive, but in the long run they are a smart investment. They use far less electricity, produce much greater light intensity, and have a much longer life span than fluorescent bulbs. (When I say longer life span, I don’t just mean a few extra hours--we’re talking 2-4 times longer than a fluorescent bulb will last.)

But not just any LED light will do. You need to buy an LED light that is designed for gardening use, to ensure it gives off the full spectrum of light that your plants need. (Again--stay tuned for more on that!)

So don’t just grab any old LED light from the hardware store; buy one from the horticulture/gardening section. If you're growing a larger number of plants, LED lights are great because they don’t produce the heat that fluorescent bulbs do.

Another plus: LED lights won’t shatter. Just in case you are clumsy, or, like me, have some little people running around the base of your set-up.

HID lights

HID stands for “high intensity discharge.” Before LED lights became popular, HID lights were very common for large-scale indoor gardening. They are very powerful and can be relied upon to grow sun-loving plants, like tomatoes, to maturity.

Downsides are that they generate heat, are not energy-efficient, and are pretty expensive.

Light Color 

Although light appears white to us, it really has a full spectrum of wavelengths in rainbow colors. (Remember light passing through the prism in science textbooks?)

Both the red and blue parts of the light spectrum are the parts that the chlorophyll in plants require to grow. Gardening is all about giving plants what they need to grow, so the fact that they need a variety of light (both red and blue light) is important. If it’s important to the plants, it’s important to us as gardeners.

Cool vs. warm light

Although it’s a bit confusing, terms like “cool” and “warm” are used to describe different light colors. These words are not referring to heat or lack of it; they are referring to the color of the light.

“Cool lights” are lights that mostly give off light in the blue and yellow part of the spectrum. “Warm lights” give off light in the orange-red wavelengths. Incandescent bulbs give off mostly “warm” light, and fluorescent tubes often give off “cool” light. You can usually spot the different between cool and warm lighting--cool light appears brighter and blueish, warm light is softer and more golden.

(For some reason, this discussion reminds me of string lights at Christmastime. Have you ever seen two different types of lights on the same Christmas tree--warm and cool? It’s irritating.)

Cool light can be enough to support leafy plants and vegetable seedlings. If you are only interested in a cool growing light, something like this LED bar light, which you can set up horizontally or vertically, would be a place to start.

Full-spectrum lights

Flowering plants, however, require “full-spectrum” grow lights. These lights, also referred to at times as “balanced” or “natural”, give the full spectrum of light--the whole rainbow. This is necessary as flowering plants need warm light at different points of their growing phase.

Light color, or “temperature”, is measured in Kelvins. You will see numbers like “4000K” when shopping for grow lights. The higher the number, the cooler the light. Herbs, leafy vegetables, and seedlings will do fine with higher spectrum lights (6500K). Fruiting plants and flowers will need added low spectrum bulbs (3000K). Full-spectrum lights will ensure that you’ve covered all your bases.

Mixing & matching different types of lights

Some gardeners opt for the inexpensive option of mixing and matching their own lights. Providing light from both incandescent and fluorescent bulbs will, together, give the whole spectrum of light. If you’re going to try this out, a ratio of 3 to 10 is suggested. For every 30 watts of light from an incandescent bulb, provide 100 watts from a fluorescent source. Another thing to remember is that incandescent and fluorescent bulbs have different life spans; you will have to switch out the incandescent bulbs earlier than the fluorescent.

This mix and match approach can easily get tricky, and difficult to ensure that all your plants are getting equal coverage and equal amounts of the full spectrum of light. Again, this is where that “full-spectrum” grow light is ideal. Although more expensive, it can really simplify things and keep all your plants happy.

If you’re a beginner with grow lights, full-spectrum lights are a good starting point, rather than trying to fiddle with just the right mix of cool and warm. And if you grow a variety of plants, as I do in my own garden, the full-spectrum lights will keep everyone happy--from herbs to tomatoes.

Light Duration: How many hours of light do plants need?

Plants need light, but they also need times of daily rest and darkness. (Don’t we all? Let’s take a lesson from the plants.) During this time, plants convert the energy that they captured during the day into growth.

Some plants require periods of darkness to trigger flower buds. Of course, out in nature plants get this time of rest by the cycle of day and night. When you bring gardening indoors, this is another thing you will need to replicate.

Even the best grow lights aren’t quite the same as sunlight. Generally, plants will require more hours of light from an indoor source than they would from the sun.

A good rule of thumb is 16 hours per day. This allows 8 hours for your plants to snooze. The lowest number I came across in my research--a bare minimum--is 6 hours of rest required per day.

One of the best ways to monitor your light duration is to set up a timer to automatically turn your grow lights on and off. These are not expensive and are simple to set up; for less than twenty dollars, you can forget about babysitting your plants every day.

Light Intensity 

Light intensity can be adjusted first by the brightness of the bulb.

The higher the wattage, the higher the intensity.

When you’re checking out light intensity, one thing to be aware of is the PAR acronym. PAR stands for Photosynthetically Active Radiation, and it measures the amount of light that plants can use. This is different from lumens, which measures only the light detected by the human eye.

Don’t be totally swayed by a high PAR number. The figures can be misleading. The PAR number measures the amount of light in the center of the area being covered, directly under the light. So if you’re imagining a tray of seedlings, a great PAR number is really only great for the seedling smack dab in the middle. What about the ones on the edge? Some of the best grow lights actually have lower PAR numbers, because they spread the light over the entire area more effectively than a light that just blasts the middle.

So, all that to say … a PAR number is pretty much pointless. Phew. There’s at least one acronym you can just skim over as you browse grow lights. Many companies don’t even advertise them, because it’s really not a reliable measurement.

Grow light distance to plants

Besides bulb brightness, another way to adjust light intensity is how close the bulb is to the plants. A weaker light, placed close to the plants, can provide the same intensity as a stronger light placed further away.

It’s a pretty logical concept, but one thing you should keep in mind here is that incandescent lights give off heat, so they should not be placed too close to your tender plant leaves.

Fluorescent lights, giving off less heat, can be placed closer. If you notice any browning or “burning” on your leaves, that’s a sign that the light is too intense and the bulbs need to be move further away.

Assembling and Adjusting Grow Lights 

If you’re wanting to grow a lot of plants efficiently and inexpensively, you can build you own set of basic wooden shelves, complete with pulley systems that will allow you to lift your lights higher as your plants grow. This would work in a situation where space and aesthetics aren’t really top priorities.

If you’re like me, you just glazed over as you read the last few sentences. Perhaps you envisioned your small living space overcome with clunky scaffolds and chain pulleys.

Stick with me.

You don’t need to check out of the grow lights discussion if the idea of a building project makes you feel completely overwhelmed. Like I mentioned, there are products out there designed for every type of indoor gardening need--you’ll find a grow light that gives your plants what they need, with a set up that fits into your space, and even adds to the style of your home if desired.

Key features for adjustability

For many home gardeners, the DIY approach is less attractive after considering all the different products already out there. The grow light stands you can buy are more aesthetically pleasing, will fit into your living space more easily, and are easy to assemble.

A key feature to look for is the ability to adjust the light height. Remember, it’s all about providing the plant with the light it needs. Being able to easily adjust the light allows you to tweak light intensity and to accommodate all the plant growth that you will surely be experiencing with all this tender loving care!

While the ideal distance between your light and your plants depends on the type of bulb and its intensity, there are some basic guidelines:

  • Fluorescent grow light: 3-12 inches away from plants
  • LED grow light: 12-24 inches away from plants
  • HID grow light: 24-60 inches away from plants

A very simple option are grow lamps that stand on their own. Some of these are as small and unobtrusive as the lamp you had on your college dorm desk. While they’re small-space friendly and super easy to set up (plug in!), a downside is that they do not distribute equal light.

Panel lights

If you want to provide a whole tray of seedlings with light, a panel light is really the way to go.

Even then, watch carefully for signs that plants on the edges are not getting enough light. If they start leaning in, toward the center, they are telling you that they are craving more.

Tube lights, even new ones, often give off weaker light at the edges. For this reason, regularly rotating your plants is also a good idea.

Should I get a timer for grow lights?

When you’re setting up your indoor growing space, remember the bit about light duration.

Plants need to be put to bed every day! They require 6-8 hours of rest in darkness in every 24 hour period.

So, yeah, invest in a light timer to control how many hours of light your plants are getting, and to ensure daily rest times. For less than $20, it’s a good investment!

Go Find Your Grow Light!

Where I live, the growing season comes to an end by September. By then, I’m harvesting all my produce, covering my tomatoes each night, and watching leaves turn dry and yellow. I’m just not ready to say good-bye to gardening yet. At the very least, I’ll be itching to start even earlier next spring.

I’m coming to the realization, with a bit of research, that grow lights are really what I need to maximize my growing season, and to enjoy a hobby I love even when the situation outside isn’t ideal.

I don’t know what your reasons are for bringing your plants indoors, but I hope you feel a lot more informed and confident. I hope a few acronyms and words that were once unfamiliar jargon now make sense, and will help you navigate the many options out there as you find what works best for you.

Are you ready to make the leap? I am!