Starting Seeds on the Windowsill
by Ruth S. Foster
As the days lengthen the gardening bug begins to buzz around again in one's head. Starting seeds is still a pleasure I enjoy and do most years. Before the spring snow has melted, I can tell from the angle of the sun that it's time to start the seeds.
People always started seeds on the windowsill. It wasn't difficult, the percentage of success wasn't bad and it was an enjoyable response to spring's siren call.
Up North the summer season is short, so starting slow growing annuals that don't reach full bloom in September, like my beautiful blue Dutch salvia, is not as smart as buying a few flats professionally grown in a warm greenhouse. But never mind.
Starting seeds at home is still a fun thing to try. With reasonable care, most will grow.... Eventually that is.... The secret, I have discovered through long experience, is to be realistic. Mother Nature never guaranteed that every single acorn would become a giant oak. Not all seeds either, so don't fret.
The basics are not complicated, but there are a few little tricks to help things along.
A good warm South facing sunny window works well. A scientific, seed starting set-up with lights works even better. Light is the most important thing once seedlings start. Without it, seedlings become tall and leggy. I have grown mine without additional lights and they've done OK. They are just slower and have to be planted deeper when they get put out in the garden.
Bob, a superb gardener friend who graces my garden with his vigorous heirloom tomato seedlings, grows his seeds in the cellar under lights. ( 18 hours a day and cool- 60 degrees).
Fluorescent lights are usually 6-12 inches above the plants. Incandescent light bulbs are too hot and can burn.
Potting Mixtures: Bob's is sand, potting soil, vermiculite and a dash of super-phosphate, and adds very weak, diluted liquid fertilizer at each watering.
Most bagged potting soil is vermiculite, peat moss, composted forest or agricultural products, peat sedge, occasionally lime, and fertilizer components, often manure, inorganic chemicals or slow release coated pellets.
A test by Consumer Research Magazine showed that for transplants, though not seeds, bagged potting soil with slow time release fertilizer already added produced more flowers or tomatoes than plain potting soil to which the fertilizer was added by the gardener. I am not convinced. I'm just reporting this tidbit.
I started some seeds in just such a potting medium and they developed fungus gnats. These are tiny black flies whose miniscule larvae eat the roots. Fortunately there is a simple, though temporary, cure for these flying pests.
To control fungus gnats crumble "MOSQUITO DUNKS" (Bacillius thuringiensis israeliensis) on the soil. Repeat as needed, usually monthly. This safe, non-toxic BTi kills fungus gnats in the soil as well as mosquitoes and black flies in ponds and water gardens. Sold at garden centers, it's manufactured by Summit Chemical Company, 7657 Canton Center Drive, Baltimore, Maryland, 21224.
Soaking seeds overnight improves germination time and rate, but soaking over 24 hours ruins the seeds. PLANT SEEDS in flats, with plastic or saran wrap covers to conserve humidity, until they sprout. After they sprout keep them moist by misting. Thin them if they are too thick.
The English think that the jostling of transplanting when they have 3 sets of leaves makes them put out more growth hormones, but I've never seen any scientific studies verifying this. Anyway, when transplanting, use a pencil and hold by a leaf tip, not by the stem. Bob moves them to 4 inch pots to grow on until they are planted into the garden.
Fertilizer helps. But half strength please. These are babies. Most balanced fertilizers will work, either liquid (diluted 1/4 to 1/2 strength) or slow release pellets. Compost in the soil also helps. Granular fertilizers may burn delicate new roots unless buried a couple of inches deep. Be careful though. Too much fertilizer, especially nitrogen, will cause to weak, rapid growth. Ideally, a good seedling should be short and sturdy.
When to start different seedlings. For slow growing varieties, calculate how long it will take to get a sturdy 4-6 inch seedling. It's not so easy to calculate this. Why is it that the more complex a task, the more we cherish the result ?
Growth rate is affected by light, heat, moisture and more. Here are the number of weeks ahead to sow some common seeds before the date you expect to plant them outdoors in your area.
Timetable for vegetables:
4-6 WEEKS Leaf Lettuce
6-8 WEEKS Basil, Broccoli, Tomatoes
8-10 WEEKS Cucumber, Pepper, Eggplant
Timetable for easy-to-grow annuals:
6-8 WEEKS Cleome, Cosmos, Gaillardia, Marigold, Morning Glory, Sweet Alyssum, Zinnia
Anyone can push a bean in the soil and expect it to sprout within a few days, but not all seeds are so easy. If you tackle something slow and difficult (like many flowers) be patient. If you just want the fun of watching thing grow, pick easy ones.
Boring Technical Information:
Different seeds have different germination times, ranging from fast ones like marigolds at about a week to, gaillardia and lupine which can take 3 or 4 weeks just to sprout. Read the back of the seed packet.
Some seeds must be fresh, others have a long shelf life. To test old seeds, put some between wet paper towels and see if they sprout. When in doubt, buy fresh seeds. Seeds need good contact with the soil, , so the growing medium is often very lightly tamped down with a small board.
Bottom heat, supplied by an electric propagation mat or a warm (but not hot) radiator helps slow starters to germinate, especially perennials and herbs, even wildflowers. It's challenging to try these from seed, which is often a two year endeavor, but eminently satisfying.
Don't plant seed too close together. It's easier to separate the roots when they have enough space. Also it inhibits DAMPING OFF DISEASE. ( Seedlings fall over and wilt from a fungus infestation.)
To thin seedlings, cut the weak ones off with scissors. Pulling them out damages the delicate roots of those that remain.
When sowing very fine seed, water the soil from the bottom (by standing the pot or tray in water until the top becomes wet) then broadcast the seed over the top.
One expert greenhouse gardener I know covers the seeds with a layer of newspaper which is then kept moist by misting the paper so the seeds do not wash around. Works for small and large seeds as well. Most seeds germinate best in darkness which is why one lightly covers them, usually about 1/4 to 1/2 inch, depending on seed size. The bigger the seed the deeper one plants it.
The New England Wild Flower Society Framingham, Massachusetts (www.newfs.org) has many unusual wildflower seeds and a seed catalogue that explains the tiny nuances of many esoteric seed varieties: darkness, light, heat, chilling, moisture and more.