The threshold of the gardening season features the season opener, likely in your kitchen: seed starting. Now is the perfect time to get going with this project.
Young transplants that you start from seed will save you a small fortune. A $2 packet of, say, tomato seeds will contain at least 20 seeds: that is 20 plants that you don’t have to buy in May. At $1 each plant or $20 for the batch (sometimes more sometimes less) you will spend later, will cost you about $4 today in seeds and supplies. That is a $16 saving or, put another way, a 500% return on your investment, in just 8 weeks!
Seed starting is immensely satisfying. Kids love to watch seeds sprout and mature. They tend to see it for the miracle that it is.
Where to start. Here is our step-by-step guide to successful seed starting.
Begin by identifying where you will grow your seeds. Some seeds need light to germinate, most don’t, and others like gentle heat, like on the top of your fridge where the heat radiates up from the back of it. Once germinated, all seeds need light. The more the better. A south or west facing window will suffice. If you don’t have one add artificial light to augment what you have naturally.
Seeds. Buy fresh seeds. By law, the seed packets that you purchase from racks or buy online this time of year were harvested last year from the 2021 crop. They are fresh. Seeds that linger in your junk drawer may still be viable. To determine if they are, perform a germination test by placing a few seeds on a pre-dampened paper towel, roll it up and do not let it dry out for a week to 10 days. Unroll it from time to time to see if the seeds have produced a white shoot. If they have, your seeds are good to grow this year. If they have not, after 10 days, throw the works into your compost.
Supplies. You will need seed starting trays and soil. Though, the soil is soil-less, and will contain peat, perlite, sterile compost and maybe a little sand. Look for “seed and cutting” mix at your retailer. And if you wish to avoid using peat, consider an alternative like coir, harvested from the sustainably grown coconut, or add more compost.
A transparent “greenhouse” top placed over your newly sown seeds will hold moisture and encourage early germination. If you see any sign of powdery mildew, which appears like a soft, faint cotton ball, prop it open with a popsicle stick to allow air to circulate through.
When to sow. A seed packet will usually tell you when to sow the seed. We sow our tomatoes 6 to 7 weeks before we plant them out in late May and early June. The second week of April is perfect. The goal is to grow a short, stocky healthy green transplant that is not leggy or overgrown. Pay close attention to the timing as the start time differs by species.
Rotate. The seedlings growing in a sunny window will turn towards the sun. Just as we migrate towards the fridge when we are hungry, plants get most of their nourishment from sunshine. Turn them every day or two to keep them growing evenly.
Harden them off. About three weeks before planting out, place your young, tender seedlings out of doors for a few hours, first in indirect light, and each day for a longer period and more direct light until they are completely acclimated to the out of doors. A cold frame is very useful for this purpose.
And finally, be prepared for some failures. Growing from seed requires consistent and daily attention to detail. A little work, a little risk, for a big reward.
Mark Cullen is an expert gardener, author, broadcaster, tree advocate and Member of the Order of Canada. His son Ben is a fourth-generation urban gardener and graduate of University of Guelph and Dalhousie University in Halifax. Follow them at markcullen.com, @markcullengardening, and on Facebook