Barbara Ellis — Seeds to Seedlings

Longer days — if not warming temperatures — signal the coming of spring. That means I’m up to my elbows in seed-starting mix, plus making space for heat mats, pots, and seedlings. To be truthful, before I have room to begin sowing, I have to clear enough space in my greenhouse for the project. Actually more of a garden room, the greenhouse is carved out of half a garage next to the house. It has windows along two walls and a conventional roof, albeit with skylights. It’s insulated, and I keep the temperature just below 60°F. Despite the lack of a greenhouse roof open to the sun, it allows me to overwinter many more plants than I could if they all had to find room in the house — with enough space for seedlings, provided I clean it up in midwinter.

Houseplants and tender perennials occupy positions along the windows, and boxes of overwintering cannas, et cetera, fill a large chunk of the floor space. I use a really simple system to organize all the seeds I sow each spring. First, I gather up envelopes — 8×10-inch ones are best — from the recycling box. I sit down with my calendar, reference books, and computer next to my pile of seed packets and sort them into envelopes based on sowing dates. Starting with the first seed packet, I count backward from my last spring frost date to determine the sowing date, then write the date on the outside of the envelope and on my calendar (see Season of Seeds for information on determining your frost date).

I repeat the process with each seed packet, adding some to existing envelopes and making new envelopes and sowing dates for others. For example, I’ll have one envelope for seeds that need to be sown 10 to 12 weeks before the last frost date — geraniums and petunias, for instance — and another for ones that are sown 4 to 6 weeks before last frost. Sowing information is on the backs of your seed packets.

The exact number of envelopes and sowing dates varies according to what I’m growing in any given year. My goal is to gather together seeds that all need the same general treatment and schedule. I’ll frequently have separate envelopes for cool- and warm-season crops that have similar sowing dates but different transplant schedules. Here’s why: Cabbage (cool season) is sown indoors 6 to 9 weeks before the last spring frost and transplanted to the garden 2 to 3 weeks before the last frost date. Peppers (warm season) are sown indoors 6 to 8 weeks before the last frost date and need to be transplanted on or after that date. Even though they are sown at roughly the same time indoors, transplant time is decidedly different. Keeping the seed packets in separate envelopes helps me remember to keep them on the proper schedule.

This all may sound complicated, but once you have all your seeds sorted into envelopes, it’s easy. As you sort, jot down any notes you may need on the outside of the envelope (refer to the seed packets themselves when sowing time arrives for exact requirements like depth or need for light or darkness). Then, when the first sowing date on your calendar arrives, you are ready to fill pots and sow.

Sowing Basics
When I’m ready to sow, I always premoisten seed-sowing mix before filling pots. That’s because seed mix — or any potting soil, for that matter — is really hard to moisten once it is in pots. I dump it into a large plastic drywall or cat litter bucket, add plenty of warm water, then stir it around. If you start a day earlier, you can skip the stirring and just let the mixture soak up the water. Rinsed, recycled pots are perfect for starting seeds; I usually use 3-inch pots or market packs. (You can sterilize them before use in a solution of 9 parts water to one part bleach if you like, but I skip this step.)

After filling a pot with soil, rap it sharply on the table top to settle the soil, then fill again to within 1/2 inch of the top. Then it’s ready to sow. Use the recommendations on the back of the seed packets for sowing depth. Also, always stick a label in each pot with the name of the plant and the sowing date. I sort sown pots and market packs into flats for germination, keeping plants with similar transplant schedules together. Bottom heat speeds germination for most plants, so as many of them as will fit go on heat mats.

Although sown flats don’t need sunlight until seedlings emerge, for me it’s easier right from the start to set the flats where they are going to grow. That way I don’t have to clear out space later. To maintain higher humidity, I also make simple hoop houses out of bent coat hangers and drape them with plastic dry cleaner’s bags. After that, I check daily to see if pots need watering and wait for the seedlings that signal spring.

Barbara W. Ellis is a freelance writer, editor, and lifelong gardener. She is the author of many gardening books, including The Veggie Gardener’s Answer Book (Storey, 2008) and Covering Ground: Unexpected Ideas for Landscaping with Colorful, Low-Maintenance Ground Covers (Storey, 2007). She holds a bachelor of science degree in horticulture from Ohio State University, Columbus, Ohio, and a bachelor of arts from Kenyon College, Gambier, Ohio. She has worked as managing editor at Rodale Press and as publications director for the American Horticultural Society; she is affiliated with the Hardy Plant Society Mid-Atlantic Group, the Garden Writers Association, and the Perennial Plant Association. She lives and gardens in Kent County, Maryland, where she and her husband live in a renovated “green” home on Worton Creek with an assortment of rescued dogs, cats, and parrots. Her garden, which is managed organically and designed to be wildlife friendly, features a wide range of ornamentals, herbs, and edibles for both sun and shade.