Gardening: Choosing vegetable seeds
by Holly S. Kennell, WSU Extension Agent
The garden in my head in January is my favorite garden. Because it is purely imaginary, it is free of weeds and pests.
Gorgeous vegetables are visualized just as they appear in all the seed catalogs that have been arriving in my mailbox for the last several weeks.
I'm enough of a realist to know that my actual garden will never look quite as good as my fantasy garden. It can come fairly close, however.
Closing the gap between vision and reality depends a great deal on knowledge. Luckily for new gardeners, not all that knowledge has to come from experience.
Some vegetables are easy; some are usually successful, if you know a thing or two; and some are a challenge, even if you know all the tricks.
Here are some things to remember as you choose your vegetable seeds, which will help you grow your dream garden.
In the Puget Sound area we have a very long frost-free growing season, often around 225 days. Compared to the majority of the country, however, we have a very cool growing season. Hot days are rare; cool, overcast days are frequent; and evenings usually cool off, even on warm days.
Some vegetables need a certain amount of accumulated heat to mature. This is reflected in the "days to maturity" numbers in the seed catalogs. National seed catalogs assume the heat per day is warmer than we get here, so these numbers aren't accurate for us.
To get a more realistic days-to-maturity number, you usually must add 20-30% more days for heat-loving crops like tomatoes, peppers, sweet corn, squash, etc.
The silver lining to this climate story is that we can grow cool-weather crops through much of the year. In most parts of the country, spinach, lettuce, mustard greens, choys, etc., can be grown only during a very short period between winter frosts and summer heat. We can even overwinter many hardy crops like kale, chard, and certain varieties of broccoli, cabbage, onions, etc.
Some gardeners don't worry about day-to-maturity numbers. Instead, they just pick the varieties marked "early" or "fast-maturing," knowing that these will mature with the least heat. Other people order from local seed companies or ones that specialize in seeds adapted to cold or short seasons.
Another strategy is to buy from seed racks and to use purchased transplants. This is perfectly fine as long as you know your varieties. Many people assume that if a seed company or grower is offering a particular variety in a local store it must be locally adapted. Unfortunately, that isn't always true. I'm afraid it is another instance of "let the buyer beware."
Knowing varieties that have proven to grow well in your area is your safest bet. Keep a record of which ones work for you, so that you can learn from your experience. Don't trust your memory.
Keep in mind the Divine Wisdom Motto: "To remember is divine; to write it down is wisdom."
Talk to your gardening friends and neighbors about their favorite varieties. Several years ago, we surveyed a big group of local gardeners and came up with a list of commonly-used varieties. This eight-page list with descriptions is available by sending a self-addressed stamped envelope to: W.S.U. Cooperative Extension, King County, 506 Second Avenue, Suite 612, Seattle, WA 98104. Ask for Recommended Vegetable Cultivars Descriptions.
Here are a few specific hints that may be useful:
- Choose pea varieties with resistance to enation mosaic virus. This disease is widespread, but there are now resistant shelling, snap, and snow (Chinese) peas.
- A few onion varieties bred for growing in the south may never bulb up here. Bulbing is triggered by day length, which is totally different at our latitude.
- Tomatoes are a favorite crop, but not an easy one. Good varieties include Early Girl, Champion, Fantastic, IPB (Early Swedish), Sun Gold, Stupice, and cherry types.
- Most of the soils in our region heat up very slowly in the spring. Seeds that need warmth to germinate may just rot--especially beans and the "super sweet" (sh2) corn varieties. Raised beds will help, as will clear plastic over the soil several weeks prior to planting.
- Many gardeners pre-sprout their seed or grow transplants to avoid germination problems. Make sure that your transplants are timed right for this climate. Our last spring frost is between late March (Seattle and favored locations near the Sound) and late April (inland and higher elevations). Seedlings of tomatoes, peppers, basil, squash, and other heat lovers shouldn't go out until mid to late May, unless protected by coldframes or rowcovers.
Holly Kennell is a Community Horticulture Agent for WSU Cooperative Extension in King County.