Up here in Zone 5 (ish), March is a slog.
It’s not that the weather is terrible, or not just that the weather is terrible, but Illinois March is cruel– you know there’s a springlike day just struggling to get out, but winter Just. Hangs. On.
What’s a gardener to do?
Seed Starting 101
Roughly my presentation
at the Chicago Flower and Garden Show
DIY stage, March 10
- Space—how much space in your seed starting area, how much space in your garden
- Cost—I never started seeds until about 7 years ago, because I wasn’t growing all that much; once I started expanding my garden nursery starts got too expensive
- What you’ll eat
- Something new
Type of seeds:
- GMO (Genetically Modified Organism) produced by any means of genetic modification, whether by modern genetic engineering or age-old plant breeding methods
- GE Genetically Engineered—these are your Frankenseeds, and are not commonly encountered in home gardening
- Hybrid- An “F-1”, or first generation hybrid, is created when a breeder cross-pollinates two pure plant lines to produce a seed with desirable traits (such as disease resistance, uniformity, or color) from both parents; not stable from generation to generation
- Heirloom, aka open pollinated is a stable hybrid—breeds true from single parent. Generally the plant needs to be stable for 50 years to be considered an “heirloom”
- Winter sowing
Materials to start seeds indoors
- A warm surface or a seed heating mat
- 12 to 14 hours of light—a sunny window is not enough. Get specifically grow lights, or just get a shop light with one warm fluorescent tube and one cool flurorescent tube, OR get can clamp lights with a 150 or 200 W CFL bulb
- Sterile containers*
- Seed starting mix
- An electric fan
Sterile containers can be purchased seed starting kits, biodegradable pots, standard ceramic pots, plastic 4” starter pots, TP tubes, DIY newpaper pots. But if they aren’t new, you must sterilize them with heat, 10% bleach solution, or rubbing alcohol.
Step by step for indoor starts
- Make a calendar—you want 4” tall plants on planting day, with at least 4 sets of leaves. Your seed packet should tell you how long from planting to sprouting; assume 3 to 4 times that for plant out date. So a tomato will sprout in about 6 to 8 days; and get to four inches in 3 to 4 weeks. In other words, don’t start tomato seeds indoors before the beginning of April or later, because you can’t plant them until late May.
- Sterile containers can be purchased seed starting kits, biodegradable pots, standard ceramic pots, plastic 4” starter pots, TP tubes, DIY newpaper pots. But if they aren’t new, you must sterilize them with heat, 10% bleach solution, or rubbing alcohol.
- Moisten the starter mix (only moisten what you will use today)
- Slightly underfill your containers
- MAKE MARKERS BEFORE YOU PLANT. Again, creative reuse, popsicle sticks, plastic plant markers, etc. Use a black sharpie or laundry marker so the writing doesn’t fade or run
- Lay your seeds on the surface of the cell or planter, then cover with the correct amount of starter mix/soil—the packet will tell you how deeply to plant, but generally you want the seed twice the depth of its largest dimension.
- Overplant. Assume 80% germination on freshly purchases commercial seeds, 50% if you’ve gotten seeds at a seed swap or by saving them yourself.
Taking care of your seeds
- Most vegetable seeds will sprout in a week. Some, like beans or radishes, will sprout in a couple of days. Some, like basil, parsley and parsnips, may take a month.
- Keep them moist but not soaking. Until they sprout you can help keep the soil moist by laying a piece of plastic wrap over the top of the pot.
- Water seeds and sprouts from the top, seedlings from the bottom
- Because no indoor light is the same as sunlight, keep those lights on 14 to 16 hours a day. Use a timer.
- Once they’ve sprouted, place a fan on low in the room. Doesn’t need to be blowing on them direct, but this will help keep fungal diseases like damping off at bay, and will make the stems stronger.
- Be ruthless—pinch off weaker seedlings until you have only a few more than you need. Once you plant, donate the ones you don’t need to your local garden club sale or school garden.