Four easy ways to start seeds indoors
Hello March! This is the month when I get serious about seed starting.
I’ve already planted slowgrowing vegetables, flowers and herbs beneath my grow lights and by late March, I’ll have sown heat lovers like tomatoes and peppers too.
Starting your own seeds indoors allows you to take advantage of the diversity of varieties available from your favourite seed companies, but if you have a big garden it can also save money.
There are many ways to start seeds indoors, but the biggest consideration is light. You need a bright south-facing window or a grow light. I use grow lights to ensure I can supply enough light, leaving them on for 16 to 18 hours each day. In low light, seedlings grow leggy as they stretch for the sun, impacting their vigour and health.
There are many types of grow lights available with models for every budget. I prefer LED fixtures as they use less energy and produce less heat.
You’ll also need to consider containers. Head to any garden centre and you’ll see there are plenty of options like cell packs and trays, soil blocks, and biodegradable containers, or you can DIY your own seedling pots from items like egg cartons. Here are four ways to start seeds indoors:
• 1) Cell packs and trays - Sowing seeds in plastic cell flats and 1020 trays is popular for its efficient use of space. A tray measures 10 inches by 20 inches and holds a cell or plug flat insert. This system, which fits beneath most grow lights, allows you to start a lot of seedlings at once.
You can also buy half trays whose narrow profile makes them perfect for windowsill seed starting. I typically get a few seasons out of each tray and cell pack insert, and then (as long as the tray has the recycle triangle on the bottom with a number between one and seven) recycle them.
• 2) Soil blocking - For decades, using cell packs and trays was my go-to system for seed starting. However, with the goal of reducing plastic waste, I’ve switched to soil blocking. This plastic-free method of seed starting uses molds that form compressed cubes of potting mix.
The downside to soil blocking is that you need to buy metal molds, which cost about $50 to $75 each. That said, they are made from sturdy materials and a good quality blocker should last many years.
The upside to soil blocking, is that you get vigorous seedlings with a well-developed root system. Instead of circling around the inside of a cell pack or pot, the roots are air-pruned as they grow. This results in less transplant shock when the seedlings are moved to the garden.
• 3) Biodegradable pots and flats - I’ve never been a big fan of biodegradable pots, also called plantable pots. They’re made from natural materials like peat, coconut coir, or manure. The idea is that they’re planted into the soil at planting time along with the seedling.
And while planting a biodegradable pot minimizes root disturbance, in my experience, our growing season isn’t long enough for the pot to break down. The pot remains around the root ball, preventing it from growing into the surrounding soil and stunting plant growth. If you wish to use biodegradable containers, peel them away from the rootball before transplanting.
• 4) Recycling - Recycled items like toilet paper rolls, egg cartons, newspaper products and cardboard tubes of toilet paper or paper towel rolls can be used to start seeds indoors. Like biodegradable containers, these should be removed at transplanting time.
Egg cartons are handy, but they don’t have a lot of root room. I start quick-growing plants, like cabbage, kale, cucumbers, basil, and broccoli, which only need four to five weeks of indoor growth. By the time they’ve outgrown the egg carton cups, they’re ready to be hardened off and moved to the garden.
If using cardboard rolls from toilet paper, start by turning them into mini pots. Using scissors, make a handful of one-inch cuts at the bottom of one end of the roll. Fold these in to create a bottom to the pot. I then place them in a plastic container or tray to keep them upright. Fill with dampened potting mix and plant.