SPRING TIPS IN THE VEGETABLE GARDEN
Dr. Leonard Perry, Horticulture Professor Emeritus
University of Vermont
Planning the garden layout, starting seeds indoors, and making coldframes are some of the spring activities for this year’s vegetable garden.
In planning your veggie garden layout, avoid planting members of
the same plant family in the same spot that they were in last
year, or even the year before. This is called “crop rotation.”
Members of the same family are susceptible to the same diseases
and insect infestations, and utilize the same nutrients. Planting
crops from the same family in the same bed, year after year, can
deplete soil nutrients, even with proper fertilizing.
For example, avoid planting members of the tomato family
(tomatoes, potatoes, peppers, and eggplant) in the same place year
after year. Likewise, the cucumber family contains this and
melons and squash; the onion family has, in addition, leeks and
garlic; the cabbage family has this crop and many others such as
broccoli, cauliflower, kale, radishes, and turnips.
There are various other crop rotations you may read or hear
about, but a simple one revolves around nutrient use. Leafy crops
(lettuce, spinach, cabbage for instance) need lots of nitrogen, so
start them out in beds that are new or enriched well with compost
and manure. The next year, in this same bed, planting fruiting
crops such as tomatoes, squash, cucumbers, and peppers. They
don’t want much nitrogen, but lots of phosphorus.
The third year, in that same bed, plant root crops such as onions
and carrots. These mainly need potassium, and grow fine if there
is less nitrogen and phosphorus from the previous years. Finally,
in year four, plant legume crops such as beans and peas that
actually put nitrogen back into the soil. Add lots of compost and
manure the fall of that fourth year, with other nutrients, and
you’ll be ready to restart your rotation the following spring.
I garden in several raised beds, and simply rotate crops among
them from year to year—perhaps the simplest form of crop rotation
and the minimum you should work toward. With this, I can usually
manage a couple years between having the same crop in the same
bed. Keep a simple layout map of your beds and plantings from
year to year to help in your planning.
If you start seeds under grow lights or fluorescent shop lights
indoors, check the tubes for signs of age. Tubes that have been
used for two to three seasons probably have lost much of their
intensity even though they look fine. Dark rings on the ends of
the tubes are a sign they need to be replaced.
To get an early harvest of lettuce and other greens, dig out a
large shallow container and sow some seeds. Grow them indoors
until the weather warms enough to put them outside during the day.
Keep cutting leaves from the outside of the plants to prolong the
harvest. Or, you can sow seeds for a mesclun mix and cut off the
leaves when still young. They will regrow for another harvest in a
Long-season alliums, such as leeks and onions, should be started
from seeds now. Sprinkle the seeds on top of seed-starting mix,
keep it moist, and as soon as the seedlings emerge place the flats
under grow lights. Snip the ends periodically to keep them about
three to four inches tall and help them to grow strong.
Check seed packets and catalogs for recommendations, then plot
out planting times for seeds you'll be starting indoors. You can
find online sowing tables too, such as one I compiled
(pss.uvm.edu/ppp/pubs/oh90sowv.pdf). Don't try to get a jump on
the season by planting earlier; larger plants are more easily
stunted than smaller ones and won't necessarily grow faster once
they're transplanted outdoors. This is especially true for melons
and squash that only grow when it is warm. Unless you give them
protection, wait until at least late May to plant them outside.
Cold frames are handy for hardening off seedlings. You can make a
simple cold frame by placing hay bales along the perimeter of a
rectangle, and placing old windows or a glass storm door over the
top. Purchased cold frames are convenient -- some have
thermostatically controlled tops that open automatically when the
temperature inside hits a designated point. Since the midday sun
can heat things up quickly, this feature is especially handy if
you're away for long stretches during the day.
When your garden soil is dry enough to work in, sow peas, spinach
and greens. Transplant cole crops such as broccoli, cauliflower,
and cabbage into the garden. You’ll need to buy cole crops as
small plants if you didn’t sow their seeds indoors back in March.
Set up the pea trellis before you plant so you don't disturb
emerging seedlings in the process.
Other spring tips for vegetables include planting a patch of
asparagus which, being perennial, should last in that location for
many years—it is a crop you do not rotate. Look into buying, or
ordering, “seed potatoes” (not seeds, but rather small potatoes)
of varieties you don’t find in stores. I like to grow potatoes
above ground in 15-gallon fabric-mesh bags, which you can buy just
for this purpose.
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