Seed Germination Database
I grow a large percentage of my flowers from seeds, since that is cheaper than purchasing plants. I also like the challenge, as some of them can be very difficult to germinate. So they provide entertainment of sorts for me over the winter months!
The plants listed in this database are those that I have tried to grow from seed at one time or another. As another family member has charge of the vegetables, this database includes mostly flowers--annuals, perennials, and tropicals--and a few unusual herbs.
I got my information from a variety of sources, including Norman C. Deno's excellent book, Seed Germination Theory and Practice, and its supplements, Eileen Powell's The Gardener's A-Z Guide to Growing Flowers from Seed to Bloom, and Alan Toogood's Plant Propagation. Online sources include The Thompson and Morgan Successful Seed Raising Guide and Tom Clothier's Garden Walk and Talk .
Of course, the sources frequently don't agree with each other--or with my own experience. In that case, I just have to make an educated guess as to who's right! A good rule of thumb is that hardy annuals and perennials should be started in cooler conditions than tender annuals and tropicals. But I generally keep even the tender annuals and tropicals at temperatures in the 60's after they are up. Cooler temperatures produce stockier--and generally healthier--seedlings.
I would recommend that anyone interested in starting plants from seeds purchase at least one shoplight--with flourescent bulbs and a timer--and keep the emerging seedlings under that illumination. They will grow straighter there than on windowsills, and an electric "sun" is more dependable during the dark months. It's also best to use a "soilless" starting mix, like Pro-mix, rather than regular garden dirt.
Seeds that require long periods of pretreatment can be kept in damp paper towels enclosed in Baggies instead of in soil. They will take up much less room in your refrigerator or coldroom that way! Besides, family members who aren't gardeners tend to be a bit squeamish about flats of dirt among the leftovers. For more information on the paper towel method, see Norman Deno's book.
As seeds sown outdoors tend to get washed away or eaten by rodents, I plant those that need outdoor temperatures in a small flat inside an empty ice cream bucket. Then I snap the lid onto the bucket and put it under a table on our porch. The lid not only keeps rodents out, it keeps the soil inside moist over a long period of time.
Below are the codes you will need to understand the germination instructions. And, at the top of this page, you will find links to the pages where the different types of plants are listed alphabetically by their Latin names. Have fun!
W: "Warm" (70-80 degrees)
C: "Cool" (60-70 degrees)
O: "Outdoor" (Start seeds outdoors, as they require varying temperatures.)
40: Refrigerate at 40 degrees until germination begins.
40-70: Refrigerate at 40 degrees for 3 months, then move to 70 degrees.
70-40: Keep for 3 months at 70 degrees, then move to 40 degrees.
C & S: Chip seeds and soak them overnight before planting.
CSO: Commercial seed only.
GA: Soak seeds overnight in water treated with gibberellic acid.
MBF: Seeds must be fresh for best results (planted soon after they are harvested).
SBW: Pour boiling water over seeds and let them soak overnight.
SD: Rub seeds on an emery board and soak them overnight before planting.
SK: Soak seeds in water overnight before planting them.
SM: Soak seeds overnight in water treated with liquid smoke.
WA: Soak seeds, changing water every day, for a week before planting.
L: Light required. Press seeds into surface of soil, but don't cover them.
JC: Just cover. Barely cover the seeds with soil, about 1/16 of an inch.
1/8": Cover with an eighth of an inch of soil.
1/4": Cover with a fourth of an inch of soil.
1/2": Cover with a half inch of soil.
D: Dark needed. Cover the flat until the seeds begin to germinate.
UP: Plant seeds upright with tip protruding slightly above soil surface.
Speed of Germination:
VQ: Very quick. (2-9 days)
Q: Quick. 10-19 days
P: Pokey. (20-29 days)
VP: Very pokey. (30 days or more)
1. Seeds with hard and shiny or fuzzy coats should be either sanded or nicked.
2. Seeds enclosed in berries should be soaked for several days--with water changed frequently--until all pulp is removed.