The Master Gardener voice mail has started up again for the 2010
growing season and from the questions so far, gardeners are anxious
to start planting. This is an unusually early spring and the
indicators are that the mild temperatures will continue. This may be
a good year to get a jump on gardening.
The most common question now is “how soon can I plant”? The short
answer is “right now”! Even with freezing nights, cool weather
crops like spinach, chard, kale and lettuce can be planted as soon as
the ground can be worked. Keep the soil surface moist to ensure
germination. However be warned that some lettuce varieties are
susceptible to frost damage after they are up. Row covers solve this
problem unless we get a night below 20 degrees.
Peas are another crop to plant early. Even the first leaves are very
frost tolerant. After the plants have emerged, mulch the row with
leaf mulch or chopped up straw to keep the plants moist and the roots
cool. Go ahead and plant your carrots and parsnips early. Add some
radish seed every four inches or so as row markers. These early
radish are frost tolerant as well.
Potatoes can be planted early and because they are generally planted
about four inches deep, they take a while to emerge. Once they
emerge, the tender leaves and shoots are not very frost tolerant so
timing is a little more important with them. Again, a cloche or
removable row cover can get this crop in much earlier.
There are a number of frost tolerant flowers too. Daffodils, tulips,
crocus, and others emerge well before the danger of frost is past but
have to be planted the previous fall. Pansies and Johnny-jump-ups are
very hardy and can be planted out after a little hardening off if
they are coming from a greenhouse.
For the rest of the vegetable garden, let soil temperature be your
guide. Crops like beans, corn, squash, cukes and the rest of the
vining crops need warm soil temperature and frost free nights. Beans
and sweet corn need soil temperatures of at least 60 degrees to even
germinate. Don’t hurry these!
Plants that you purchase or start indoors like tomatoes or peppers
are damaged by nighttime temperatures below 50 degrees. Unless you
have some way of protecting the young plants with walls of water, a
cloche, or a high tunnel, keep them in until the nights are warm.
Plants exposed to cold temperatures may never fully recover so
waiting is best. Beets are another vegetable that likes temperatures
consistently above 50 degrees.
Onions, on the other hand, don’t mind cool nights. Whether you start
your own or grow from sets, they can go in the ground very early.
Don’t plant them too deep, the roots just need to “catch” since
they grow best about half in the ground. Plants in the brassica
family (cole crops) like cabbage, brussel sprouts, broccoli, or
kohlrabi can be set out after severe frost danger is past as they
tolerate a light frost. Harden the plants off by setting the trays
outside during the day for a few days first.
