Essential Equipment for Indoor Seed Starting

A blizzard storms away outside here as March comes to a close, but our first seedings are already sprouting happily indoors. What a treat is is to start planting before the snow is even gone! I find myself beginning again with a minimalist approach to seed starting this season, because our family has recently moved to a new property with almost no existing gardening infrastructure. Sure, I have dreams of building a heated nursery greenhouse again and plumbing in some running water and a utility sink, but those upgrades will have to wait for future years. For now, I've just got an old barn to work with, and it is in the loft of this barn that I took a bit of time this winter to assemble a decent seed starting space with the bare essentials. As a result, I thought it fitting to cover the bare essentials for those of you just getting started with seed starting. You really don't need much, but what you do have matters.

The barn enjoys a peaceful "spring" day with our garden site under snow in the background.

The barn loft needed new joists, flooring, and an actual stairway to make the sapce safe and easy to access.

A few unfinished details remain, but the loft is now ready to host our seed starting station this season.

So what are the bare essentials for seed starting? To answer this we can, as usual, look to the 5 core variables that I teach in my Free Workshop: space, temperature, soil, light, and water. Optimizing growth is just a matter of controlling these five core variables, and with some pretty simple technology, we can do that just about anywhere, even in an old barn in the middle of the Canadian prairies in winter.

Here's a look at the basic seed starting setup that's going to get us through this spring.

Space

The first question you'll likely ask yourself is where to carve out some space for seed starting. I'm sure I could have found a place to squeeze some seed starting equipment into the daily living area in our home, and that would add an element of convenience to seedling care, but my personal preference is to keep the dirty work of growing food out of our clean living spaces. If I designate a separate work space for seed starting alone, I can make a mess when I need to and still live in a clean house without having to constantly navigate through a maze of seedlings.

Regardless of the location you choose to start seeds on your property, the best way to make the most of your available space is with shelving. The vegetable seedlings we need to start will only be a few inches tall so it makes the most sense to stack them vertically. The space savings doesn't seem obvious at first because shelves take up space too, but some quick math tells us that our 4 tier shelving units can support 32 ft² of growing area with a footprint of just 8 ft². That leaves me 24 ft² of free space for my morning burpees. The bonus perk of the shelving is that it makes every tray of seedlings really easy to see and move around.

The shelves I use are 2 feet deep by 4 feet wide and can be easily adjusted to different heights without the use of any fasteners. You'll see a lot of pictures of seed starting trays supported on wire shelving but not from me. I prefer the solid shelves because they don't allow spilled soil and water to rain down on top of the items on the lower levels.

Here's a link to a source for these shelves in Canada.

Here's a link to a source for these shelves in the United States.

Soil

The term "soil" is a bit misleading here, because ordinary garden soil doesn't work well for seed starting. It's not great at holding air space and moisture in the small volumes we are using for our young seedlings. Instead, we make a soilless mix using ingredients selected to provide everything our seedlings will need for the first few weeks of growth. Our mix includes peat moss, perlite, compost, lime, and a blend of organic fertilizer, and the recipe is tailored to work well for soil blocks. I especially like that our mix includes slow release fertilizer because I don't have to be concerned with mixing liquid fertilizers or wonder how much excess fertilizer could be building up around my plants over time. A common mistake for newbie seed starters is to buy some generic potting mix off the shelf and use it for all of their seedlings without realizing that the mix is just a blend of peat moss and perlite, with no nutrients to support plant growth throughout the seed starting period.

A round bucket makes mixing up potting soil easier. I use a drill and paddle mixer to speed up the process.

The finished soilless mix holds water, air, and nutrients so our seedlings can get a great start to life.

Once you've got your soilless mix sorted out, you'll need something to contain it. Here's where you've got some freedom to go your own way because it is possible to start seeds in anything from folded boxes of newspaper, to old plastic yogurt containers, to juice boxes. So technically, you could freecycle your way through your seed starting tasks using an assortment of containers with different materials and sizes, and have absolutely no initial cost. However, you may pay the price in other ways, whether it be through the extra time needed to source containers, the challenge of starting seeds in containers of the wrong size, or the burden of storing and looking at your pile of random potting devices. If you'd prefer to standardize your seed starting a little more, every garden centre should be able to equip you with a basic collection of plastic seed starting cells and pots. I'll admit that containers have disappointed me in the past though. They break easily, and create unnecessary garbage. I also know that I live a happier life without clutter. That's why I opted to go with soil blocks and avoid containers altogether. Still, there are many options that will work in this department, so consider your priorities and go your own way.

You can read more about how we start seeds in soil blocks here.

Here's a link to a source for soil blockers in Canada.

Here's a link to a source for soil blockers in the United States.

Temperature

Temperature seems to be the variable that home growers overlook the most, even though it's so easy to control. I think that because us humans can just put on a jack or extra sweater when we're cool, we don't really empathize too well with plants and their sensitivity to temperature, but imagine their situation. Their seeds, just coming out of dormancy, are realizing they have found their way into some moist soil and are now trying to figure out if they should risk everything they've got on sprouting. If the seed sprouts, it has one chance to grow to maturity and produce more seeds. If it succeeds, it can pass on its genetic information to the next generation, but if the seed sprouts and conditions are not favourable enough to grow to maturity, no new seeds are produced and its genetic information is lost forever! Ok, that was maybe a slight tangent there, but I hope I made the point that the stakes are high and temperature is the first major variable that the seed assesses when deciding whether or not to come out of dormancy. It doesn't know where it is in the world, it can't look on the calendar and see what month it is, and it certainly won't assume that it's safely planted on your seed starting table and that everything will totally workout in its favour as long as it takes a chance and sprouts for you.

Thankfully, it's not that hard to communicate to your germinating seeds that they have found a great place to grow. You just need to make sure their seed starting trays are kept at the right temperature. Every crop has a sweet spot, and once you stick to these temperature ranges, your germination percentage and speed can be improved greatly. We control the temperature of our germination shelves with electric heating mats. The waterproof mats slide under our trays and warm them from the bottom to our desired temperature setting. We control the temperature with an external thermostat that has a temperature probe that can be place right between the soil blocks. If the temperature of the soil blocks is too cold, the heat mat turns on. If the temperature of the soil blocks is too hot, the heat mat turns off.

Here's a link to the type of heat mats we use.

Here's a link to the type of temperature controller we use.

Light

Intense, high quality light is critical for your seedlings because it drives growth and regulates their physical characteristics. Insufficient light has long been known to be a source of undesirable elongation in seedlings, but with the introduction of LED lighting technology and more easily modified light spectrums, we've also learned that changes to red, blue, and green percentages in the light can impact factors like root growth, stem thickness, and overall strength. So, if your serious about growing high quality seedlings at home, get yourself some good grow lights. They'll last forever and they'll work, as long as you use them properly.

To learn more about grow lights, read this in depth grow light study.

Our onions are the first seedlings up under lights at our new location.

Water

Then there's water, the one variable you can't really set and forget, the variable that's probably prone to the most accidental screw ups, the variable that's going to demand the most of your time and attention. Ugh. That's not a great introduction, but it's true. You can get everything else right and still ruin the show with the incorrect application of water.

That said, the watering job is really quite straight forward once you acknowledge the upper and lower moisture limits. We know that plants can't live without water and their roots will be starved of oxygen if we give them too much water. Our job as gardeners is to provide a comfortable amount of water that keeps our plants in between those two limits. That just takes consistent attention and a method of water application that matches your choice of containers.

I use a sprayer wand to water my soil blocks while still indoors.

What's nice about water, is that you can bring it anywhere. Yeah, a nearby water faucet and sink is ideal for seed starting, but it's not a necessity. For example, this year, in the loft of our barn, I'm just using a portable pressurized sprayer wand. After twenty quick pumps to the canister, I've got my own pressurized water supply in a location where I have no running water otherwise.

Do you have what it takes?

I hope that after running through this list of 5 core variables, you realize that setting up your own seed starting space may not be as daunting of a task as you once thought. Along with this list of equipment, your young plants with require your consistent attention and a willingness to learn. I remember feeling so stupid when I first started growing my own seedlings indoors. It wasn't because I was stupid and seed starting is not inherently difficult. It's actually quite easy when you do things the best way. What's challenging at first, is that it's also very easy to do things the wrong way, and one simple wrong step can be the difference between life and death in the seed starting game. If you're new to seed starting, enter this world with optimism and excitement, knowing that you'll kill plants along the way, but confident that you'll learn from the process and carry on to master the art in time. If you want to take the fast track, join me in the Seed to Table course community.

Happy seed starting!