Using Grow Lights for Seedlings and Indoor Gardens
Do you want to start garden seedlings indoors? You can grow healthy seedlings and plants indoors, with some supplemental light. Learn about using grow lights, plus tips to make an inexpensive grow light shelving unit.
Growing plants indoors is an enjoyable project for any gardener. Whether you want to start your garden seedlings, grow herbs inside, cultivate an indoor vegetable garden, or provide supplemental light to your houseplants during winter, using grow lights will help you raise healthy plants.
What is a Grow Light?
A grow light is an electric light that simulates natural sunlight. Plants need light for photosynthesis, which is the process of converting light, oxygen, and water into energy that helps the plant grow. In order to grow healthy seedlings and plants indoors, you will need some supplemental light. Using grow lights will provide
Natural sunlight contains all the color in the spectrum from red to blue, and yellow to violet. Grow lights are used to create an artificial light that closely replicates natural sunlight.
Commercial growers and greenhouse gardeners have additional lighting options, but for home growers, fluorescent or LED grow lights are all you need for starting seeds, and growing edibles indoors.
- Fluorescent Lights are budget friendly and ideal for germinating seeds, growing herbs, and leafy greens indoors. Fluorescent lights are not very expensive to use, don’t heat up, and are available in many sizes to fit your shelving. You can use full-spectrum bulbs, or a mix of cool and warm bulbs in order to recreate the full spectrum of light.
- LED Lights (Light Emitting Diod) offer full-spectrum lighting ideal for growing seedlings and plants indoors. They cost a bit more than fluorescent lights, but last longer, use less electricity, and provide better light spectrum than fluorescent bulbs. The pricing on LED lights has come down significantly over the years.
Benefits of Using Grow Lights for Seedlings
Get a jumpstart on your vegetable garden by growing your own transplants from seeds. Seedlings need more light than a windowsill can provide to grow healthy and strong. When they are not given enough bright light, the plants will grow weak and leggy. Using grow lights to start seeds is a great way to grow healthy transplants for your vegetable garden.
Starting your own vegetables, herbs, and flowers from seeds indoors under grow lights offers a number of benefits, including:
- It is less expensive than purchasing garden transplants.
- There is a greater selection of seeds available in comparison to the standard plant varieties at most local nurseries.
- You have full control over the quality of the plants. When you grow your own transplants, you know that they are well cared for and raised without unwanted chemicals.
- It provides a little gardening therapy during the winter months when the ground is under a layer of snow.
Using Grow Lights for Indoor Herb Gardens
Culinary herbs can be grown indoors on a sunny windowsill, but more light will help grow healthy dense foliage. Grow lamps can provide enough light so you can grow herbs that flourish inside even in winter. The article below provides information on how to start an indoor herb garden, plus which thrive inside:
Growing Vegetables Indoors with Lights
In addition to starting seedlings and herbs, artificial lights can also be used to grow many vegetables indoors. Most leafy greens and some root vegetables will grow very well inside under lights. Freshly harvested lettuce, spinach, and radishes are a treat in the middle of winter. The article below will help you get you started with your indoor vegetable garden:
How to Build a Grow Light Shelving Stand
When I first searched online for grow light shelving units for starting seeds indoors, I quickly discovered that they cost way more than I wanted to spend. A three-shelf unit with lights was well over $400 at the time (and around $600 as of 2022!). If you have the money to splurge on a grow light system, this 3-Tier Garden Grow Light Kit from Gardener Supply is a dream.
I could not afford such a unit, so this required some creative thinking to figure out a less-expensive option for starting seeds indoors. After shopping around, and learning my options, I built a grow light shelving unit in our basement using sturdy wire shelving, shop lights with florescent bulbs, a power strip timer, and seedling trays. I have used it for over 10 years now!
Parts for Your DIY Grow Lights
You can assemble your own inexpensive grow light shelving stand that will serve well for starting seeds indoors and growing an indoor garden. This is a simple and affordable grow light shelf made from easy to find equipment. Here is what you will need:
Look for a wire-shelving unit that accommodates 4-foot strip lights. I wasn’t able to find a large shelving unit locally, but I did find some 23-inch 3-tier shelving units. Two of these units placed side by side are the perfect size to hang two 4-foot shop lights across each shelf. The shelves are 13-inches deep and two standard seedling trays fit perfectly on each shelf. Plus there is room for two lamp fixtures on each shelf if more light is needed.
These 3-Tier Shelving Units can be found in big box stores or online. Be sure to select units that measure around 30 inches H x 23 inches W x 13 inches D.
If you want a larger grow light shelf, this 6-Tier Shelving Unit will more than double your growing space.
Fluorescent and LED lights come in all different shapes and sizes. You are looking for fixtures that will fit your shelves. If your shelves are 48-inches wide, then look for 4-foot fixtures that will distribute light evenly across the shelf.
The lights I use are your standard 40-Watt 4-foot shop light fixtures found in big box stores or online for around $30. These come with chains and a couple s-hooks. You will need to pick up extra s-hooks to hook the chain to the wire shelving.
Check the packaging of your lights to be sure you are buying the correct bulbs to fit your fixtures. The lights come in different sizes, including T8 and T5. The “T” in T5 stands for the bulbs is tubular shape, while the “5” denotes that it is five eighths of an inch in diameter. Older shop light fixtures that you may have around your basement or garage are T12. It may be difficult to find T12 bulbs.
Fluorescent light bulbs also come in full-spectrum, cool, or warm colors. Full-spectrum bulbs provide a balance of cool and warm lighting that represents natural lighting from the sun. Full spectrum lighting is the best for growing plants.
However, you can also mix and match a cool and warm bulb for a wider spectrum artificial light. Just be sure to rotate your trays every few days so your plants receive the benefits of both as they grow.
Cool white bulbs provide blue-green spectrum and are suitable for starting seeds, growing leafy greens, and herbs. The blue light stimulates vegetative growth of foliage and roots. Warm white bulbs provide red-orange spectrum that stimulates the production of blossoms and fruit. Red light helps regulate plant growth and development, and enhances photosynthesis. You can get a good balance of spectrum by combining one cool white and one warm white bulb in your light fixture.
If the bulb temperature isn’t shown on the box, look for the kelvin rating. Kelvin is often used as a measure of the color temperature of light sources. Full-spectrum lamps will have a kelvin rating of 5000 to 6500K. Cool bulbs are around 4000K, while warm bulbs are 3000K.
LED Grow Lights:
The newer LED grow lights offer full spectrum lighting ideal for growing seedlings and plants indoors. They are more expensive than fluorescent lights, but the pricing on LED lights has come down significantly over the years. Be sure to select the correct sizes for your shelving unit.
Power Strip with Timer
Seedlings require at least 12-16 hours of light each day. I set my power strip timer for 16 hours on, then 8 hours off. The power strip with a timer is also commonly available in big box stores or online.
Plastic Gardening Trays
You will need trays or containers to help prevent water from dripping. These black growing trays measure about 20 x 10 inches and one tray fits perfectly on each shelf. These trays are perfect for seed starting using cell packs or recycled containers. I like to double them up for a more secure tray that can be moved around without flexing. You can also use recycled produce trays or small plastic storage totes.
How to Setup Your Indoor Grow Light System:
This DIY indoor grow light system is a simple and affordable setup that is perfect for starting seeds for your vegetable garden, growing vegetables indoors, and providing light for your indoor herb garden. Here is how to put together a grow light shelf using easy to find items:
Step 1: Gather your Components
- 2 3-tier shelving units
- 4 4-foot shop lights plus bulbs if needed
- extra S-hooks
- 4 Plant growing trays
Step 2: Assemble the Shelving Units
Follow the instruction that came with the shelving units and put them together. Since the shelves are adjustable, make sure they are at the same level for both units, and you have plenty of space for the plants and the light fixtures.
Step 3: Setup the Growing Area
Locate the shelves near an outlet. Try to select a place away from heavy traffic, pets, cold drafts, and excess heat. Place the shelving units side by side. I situated the shelves on a little used workbench, but they could also be raised up on a folding table to make it easy to tend to the seedlings.
Hang your lights from the top and middle shelves using the chains and s-hooks. Plug the lights into the power strip timer and plug the timer into the outlet.
Place your plastic gardening trays on the shelves, set your timer, and start growing seedling and edibles indoors. Keep the lights about 2-inches above the plants so you don’t burn the leaves, and adjust the level as the plants grow.
Watch your plants for signs of too much or not enough light, and adjust the lights as needed for the best light intensity. Plants that are receiving too much light will show signs yellowing of leaf burning, with scorched and bleached papery spots on the leaves.
Plants that are not getting enough light become leggy and tend to stretch towards the light source. Leggy plants have thin, weak stems and large gaps in between leaves. Other signals of not enough light include pale green, yellow, or white leaves. This is a clear sign that there is not enough light for the plant to produce chlorophyll. Plants without sufficient light may also drop their leaves, especially older leaves.
Step 4: Grow Something
Here are gardening and growing tips to get you started:
I hope I have encouraged you to put together your own inexpensive grow light system that will serve well for starting seeds indoors. It is also fun to experiment with growing edibles indoors during the winter months. Check out the following articles for tips for indoor gardening:
Good planning is key to a successful vegetable garden
Whether you are new to growing your own food or have been growing a vegetable garden for years, you will benefit from some planning each year. You will find everything you need to organize and plan your vegetable garden in my PDF eBook, Grow a Good Life Guide to Planning Your Vegetable Garden.
FREE email series:
5 Easy Vegetable Gardening Tasks You Can Do in 15 Minutes or Less!
Plus get seasonal gardening tips, recipes, and ways to preserve the harvest right in your inbox each week.
The Pros and Cons of Growing Cannabis Using Aquaponics
Seasoned cannabis cultivators looking for large yields and a quick growth cycle might want to consider aquaponics. Chris Bond examines the good and bad when it comes to growing marijuana in an aquaponic setup.
How to grow cannabis hydroponically is well documented at this point. There are hundreds (if not more) of resources, articles, and how-to manuals on growing marijuana with a hydro system; not so for aquaponics. The difference between a hydroponic system and an aquaponic system may seem like only a matter of degree, but there are some definitive differences to consider.
Aquaponics is the marriage of two distinct farming or production systems combining fish farming with plant production. When it works, the results can be amazing; if it doesn’t go well, you lose two potential crops, not just one. It is not something necessarily advised for the novice cannabis grower, but may provide a fun and unique challenge to one who has already mastered some of the finer points of hydroponic cannabis production.
The Basics of Aquaponics
In almost all aquaponics systems, water circulates between the section where plants are being grown and a separate section where fish are being raised. There are numerous configurations to achieve this. Some setups have the plants directly above the fish, and some have the two systems separated in different rooms but are attached by an intake pipe and a return pipe, ensuring that the water continuously cycles between the plant roots and the fish tank.
Any plant that can be grown hydroponically should be able to be grown aquaponically (I say “should” as I cannot find any verification that all such plants have indeed been tested in an aquaponic system). The choice of fish breed, however, is somewhat limited to those that can be raised in such tight quarters in water appropriate for hydroponic plant production. Overwhelmingly, the fish species selected are one of three: tilapia, perch, or trout. Those with larger tanks can try catfish and those who are not interested in consuming the fish can raise goldfish in an aquaponic assembly.
In any healthy, balanced aquaponic system cannabis plants enjoy a continual supply of nitrogen created by the fish waste. These flow from the fish tank and can be absorbed by the plant’s roots. The plants will also get some lesser micronutrients as a side benefit, but overwhelmingly they get nitrogen. The fish get clean water as it is oxygenated and purified by the plant roots. In most systems, fish food will need to be added as well. When your cannabis plants need additional nutrients, they can be applied directly to the plants without entering the recycled water supply when a “double root zone” system is employed.
This involves creating a physical barrier between the top portion of the roots and the section that is submerged in the water. Many creative solutions and media are used for this, including various types of mesh or burlap (untreated) along with soil or other media with nutrient-holding capacity. This allows for targeted applications of nutrients such as phosphorus and potassium to the root zone, while staying out of the water supply. Foliar feeding of nutrients can also be performed if the double root zone method is not utilized.
The Pros of Growing Marijuana via Aquaponics
Most successful aquaponic cannabis producers cite the main reason for using this production method (besides producing fish as well) is that their plants can often be harvested an average of about 10 days sooner than by utilizing other growing methods. If your goal is a quick turn-around, aquaponics is certainly a cannabis growing method to consider. It is also thought to contribute to higher yields when compared to other growing methods.
Other growers cite environmental concerns.
Growing any crop with aquaponics saves water. Less water is used compared to those plants needing constant irrigation. Less water is also used because it is serving “double-duty” by keeping two separate crops alive and sated. Other growers like that it is a way to grow cannabis organically as the main fertilizer for their plants comes directly from fish. At the time of this writing, there are no recognized certifiers for organic aquaculture of cannabis; it can still be grown without using any artificial chemicals. This also results in organically raised fish for your table or to sell as an added bonus.
Regardless of the reasons for choosing aquaponics for your cannabis production, there are some very real considerations to make before jumping in.
Aquaponic systems are neither cheap nor easy to operate. They may be comparable in cost and only slightly more complicated than most hydroponic systems, but nonetheless they still cost more to set up than most soil-grown cannabis operations. It is likely additional filters will need to be set up, plus bigger pumps and larger tanks than are needed to grow a comparable amount of cannabis using only hydroponics. They are also significantly more complicated.
A successful aquaponic cannabis grower must be in tune not only to the needs of one crop and growing system, but essentially two. The grower must understand not only the needs of cannabis plants need at any given time, but must be aware of the state of the environment the fish are living in as well. It is even more vital than with a hydroponic system that the pH, temperature and electrical conductivity levels are constantly monitored. If one is out of balance, the whole system can collapse faster than more simple growing systems. This typically requires more time spent tending to an aquaponic system than any other growing method. To further complicate matters, the time required to go from seed to harvest is considerably less than it takes to go from a fingerling (the term used for many young fish) to the frying pan.
Expect the fish to take several months longer, meaning that you may be halfway through the cycle of a second crop of cannabis when you need to harvest the fish and add new ones to the system, all while trying to maintain proper levels.
Producing cannabis aquaponically is not a method generally recommended for those just dabbling in production or those who are just starting out as hobbyists. It is a step best undertaken by those who have graduated from successfully growing in soil or soilless mediums, and are ready to challenge themselves. Mastering hydroponic cannabis production, while not a prerequisite, will give the aquaponic cannabis grower a leg-up when attempting to set up and operate a viable and high-yielding aquaponics system. Once you have mastered this level of dominion over both flora and fauna, you can take pride knowing that you have reached one of the higher echelons of cannabis production.
If nothing else, fish can be a whole lot more interesting to watch while they are swimming around as you enjoy some of your aquaponically-grown bud.