The Best Ways to Set Up a Seed-Starting Station in Your Home
If you're serious about growing your own seedling starts this year, here's the setup I've come to rely on.
Seed starting certainly seems like it should be as simple as throwing seeds into soil, parking them near a window, and waiting for your new green friends to join the party. There are a slate of reasons to really consider whether you’re ready to even get into seed starting (hint: don’t do it in the first year or two of your garden). But once you decide you’re ready, you can set yourself up for success by getting the right gear to ensure you have enough heat, moisture, light, and space.
There are many ways to grow seeds, and if you have a method that works for you, don’t let me dissuade you from continuing to do so. But I’ve constructed the least time and physically consuming way to do with the least waste and most success. My methods are cobbled together from many great gardeners I’ve had the privilege of learning from over the years.
Find the right space
You will most likely grow your seeds in 1020 trays, which is a standardized size (10” x 20”), but can come in many different cell formats. The important thing here is to plan for the right depth of space and width of space to accommodate those trays. Whether you purchase commercial shelving or build your own, a shelf depth of at least 11 inches means you can only fit the trays the long way, and a depth of at least 21 inches means you can fit the trays side by side the short way. One of the only commercial shelves I’ve found that have the needed depth are Husky Heavy or Industrial Duty shelves, but the design of them means you’ll always have a shelf at the midpoint of the unit height, so you don’t have total control of the vertical spacing of all the shelves. You can also build a basic similar unit for far less money, if you have the skills.
Shelves that work as seed-starting stations:
Accommodate eight 1020 trays with a 39 inch shelf height: 5-Tier Heavy Duty Boltless Steel Garage Storage Shelving Unit (48 in. W x 78 in. H x 24 in. D)
Accommodate fourteen 1020 trays with a 39 inch shelf height: 4-Tier Industrial Duty Steel Freestanding Garage Storage Shelving Unit in Black (77 in. W x 78 in. H x 24 in. D)
Accommodate thirty two 1020 trays with a 22 inch shelf height: 5-Tier Industrial Duty Steel Freestanding Garage Storage Shelving Unit in Black (90 in. W x 90 in. H x 24 in. D)
Spacing between shelves is just as important because it must accommodate grow lights hanging from the shelf above, and allow room for the plants to grow, keeping the lights far enough away to not give the plants sunburn. As you continue growing seeds over the years, you’ll notice that different plants grow inside to different heights before they go outside. For instance, you plant herbs long before they get too tall, but your tomatoes might need a lot of vertical space. For that reason, you can space the shelves at different heights, but I have spaced my shelves at 25 inches, 25 inches and 22 inches height.
Prepare the lights
The biggest faux pas I see in amateur seed starting is inadequate light. The reality is that you need to imitate the sun, and a small directional plant light isn’t going to cut it. Without enough light, seedlings stretch to find it and become leggy and weak. You want those watts as close as you can get to the plants without burning them, and lots of them. Traditionally, growers I follow have stuck with incandescent fluorescent bulbs because they have tremendous wattage and some heat. They also suck energy and are hard to dispose of, so like a lot of people, I've moved to LEDs. In the setup described above, you’ll be running lights along the length of the shelves. If you’ve got the trays running the long way as well, you’ll only need two (but three wouldn’t hurt) lights along the length. If you’re running trays the short way, use four lights.
These lights will “throw” a beam that is wider than the light itself, but you should ensure that all the trays are covered end to end. Lights come in different lengths, so you can pull the lengths you need for your specific space to cover everything. Since I started, I’ve been using Barrina lights, and haven’t had any burnouts with any over the last six years. There are certainly other brands, I just haven’t personally tested them. LED lights can usually be linked together, and though the lights come with tons of linking extensions, you can easily buy more cheaply to fit your situation. I reconfigure how they’re linked a few times a year based on how many lights I need on.
You need to suspend the lights from the shelf above, and you will need to be able to adjust them up and down over the season. They’ll start very low, just over the seed trays, and will get raised as plants grow. You want six to eight inches of clearance for the lights so they don’t burn the plants, which LED lights are prone to do in a way incandescent bulbs aren’t. You can set up a single eye hook and chain to the end of each light, but I would recommend creating a system where all the lights for a shelf raise and lower together, otherwise it’s just a lot more work. I created such a frame using 1" x 2” wood, attached the lights to the bottom of the frame, and then hung the frame using the eye and chain method described above. I’m sure there’s an even more efficient way using pulleys.
Grow lights to help plants get enough “sunlight”:
Get enough light involved
It’s really simple: Seeds wait for the sun to warm the Earth enough before they’ll sprout. To trick seeds into sprouting inside, you need to heat them without cooking them. To do this, you use heat mats specifically for this purpose, and a temperature controller. Choose heat mats that will cover the size shelf you need, and you don’t want to overlap them. If you’re only growing one 1020 tray, they make mats exactly that size. If you’re growing four next to each other, they come in that size, as well.
Once you have the mats in place with the seed trays on top of them, you’ll want a meter that ensures the soil doesn’t get too hot or cold, otherwise you just cook the seeds. Since having a thermostat for each mat would be expensive, I get one that will allow you to connect multiple mats to it. Each mat has a probe you put into the soil, and you plug the mat into the thermostat. When the soil is too cold, it turns the mat on, and when it's too hot, it turns it off.
Heat mats and thermostats:
Set up the grow trays
This is, you might argue, the exciting part. The first thing to note is that different seeds need different size cells. So the 1020 trays come with different cell sizes. Generally, you’ll be looking at 50 cells, 72 cells, or 128 cells. Tomatoes and most nightshades benefit from the larger cells in a 50, while many flowers do just fine in a 128. Over time, you’ll figure out what you need. Many companies produce these plastic 1020 seed trays, and you’ve likely encountered many at the nursery. Generally, those are single-use plastic that disintegrate in the sun and create a lot of waste. To avoid this, some people have changed to a method called soil-blocking, which doesn’t use a tray at all, but uses a tool to create small blocks of soil that can stand on their own, and you transplant directly into the garden. It has a lot less waste. For years, I blocked. However, it is a lot of physical work to create the blocks and in an effort to reduce that workload, I have switched to a new breed of hefty, reusable molded plastic seed trays that have aeration built in, so they perform as well as seed blocks (without all the work). I’ve been using Neversink Tools Winstrip trays for the last three years, and I just keep buying more of them; I think they’re amazing. They require less seed-starting mix than seed blocking, too. When it’s time to pull these out of the seed tray, you just stick your finger in the bottom and they pop right out, with a fantastically developed root system.
Since I grow inside, I use a system called bottom watering, which means the seed trays don’t get watered from above, which is messy and needs a lot of tending. The seed trays sit in a bottom tray that has no holes, and that tray has water in it. This way, the seedlings can wick up only the water they need. Although I have many of these, I am slowly replacing them with the Neversink version, because it’s much sturdier, which will become important when you want to use these year after year.
Finally, you need a dome on the trays during the germination stage. This keeps humidity on the seed and actually reduces how much you need to water since there’s almost no surface evaporation. You remove these once the tray has germinated. Neversink sells these as well, but you can buy them inexpensively; any will do fine.
Seedling trays, bottom watering trays, and humidity domes:
Winstrip starter set (Three 50 cell, two 72 cell and 128 cell, and seven bottom watering trays)
Use a fan to encourage strong stems
A mistake I made the first year I started seeds was thinking I wanted the most humid environment possible, but that’s not really accurate. You need humidity to get seeds germinating, but after that, too much humidity can help spread disease and lead to fungus and gnats.
An addition I always have now is a small clip on fan at the end of each row to blow on my small seedlings once they’ve got enough leaves. The breeze helps strengthen the stems of these plants and moves air around. Any small clip-on fan will do.
Start seeding
If all of this seems overwhelming, remember this: You can start with one tray on a small heat mat under a decent plant light, and see how you like it before really digging in. If you’ve tried seeding before without much success, you can try a new system to see if it's more efficient or higher-yielding.
Early seed starting will start in February, so now is the time to get those seeds ordered and get your seed-starting materials cleaned and sterilized.