 Of course, we can expect some fruit reduction in cases where severe
frost or freezing catches trees in the stages of tender bloom and
early fruit set. Book figures are about a 10 percent reduction in
apples at full bloom with a temperature of 28 degrees. Peaches and
apricots in early fruit set at similar temperatures will see about a
25 percent fruit reduction. An additional decrease in temperature to
about 26 degrees magnifies the losses. Of course this isn't always
bad. Many have been complaining the past couple of years about too
much fruit and broken branches.Of bigger concern is rhubarb. A
hard freeze can actually damage leaf cells enough to release a toxin
back into the leaf stalks. The leaves are always toxic on rhubarb,
and if damaged enough to wilt or have black or brown along the
edges, the toxin is almost certainly released. The solution is
rather simple, at least this early in the game. Pull the stalks with
the damaged leaves, and you get to start over with the regrowth. It
may happen again as the plants have more growth, but at least now we
are early enough we don't feel quite so bad about starting at ground
level again.
For those who got some potatoes set out, if foliage is damaged
enough to wilt, it is probably best to cut tops back to ground level
and allow regrowth. Rotting back into the tubers causes more
problems later on.
Garlic mustard
Garlic mustard is a cool-season biennial herb with stalked,
triangular to heart-shaped, coarsely toothed leaves that give off an
odor of garlic when crushed. First-year plants appear as a rosette
of green leaves close to the ground. Rosettes remain green through
the winter and develop into mature flowering plants the following
spring. Flowering plants of garlic mustard reach from 2 to 3 1/2
feet in height and produce buttonlike clusters of small white
flowers, each with four petals in the shape of a cross. We haven't
reached the temperature threshold for the flower stalks to elongate,
but that will come shortly.
Control of garlic mustard is somewhat difficult. Seeds can remain
viable for at least five years in the soil. Small amounts can be
pulled up (including the roots). Garlic mustard can regrow from root
material.
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For herbicides, glyphosate (Roundup) is the most often
recommended. Remember, glyphosate kills broadleaves and grasses
when it gets on them. There has been some success with 2,4-D
LV400 where there aren't concerns with other understory plants.
Very large patches have been controlled with fire, but that
completely destroys the understory of timbers.
Remember to monitor garlic mustard areas for at least five years
due to the seed dormancy period. Some action at this early time may
help prevent larger problems down the road. It is much easier to
control small patches than large ones.
The to-do list
-
Get ready to mow!
Many are actually looking forward to the mowing duties after the
winter we've experienced. Use a mower with sharp blades, and
remove no more than one-third of the leaf blade — for a 2-inch
mowing height, mow when grass is 3 inches tall.
-
Roses should have
their final pruning any time now. It appears winter damage was
severe on the Knock Out roses I've looked at. Cut back to green
wood — hopefully you have some left!
-
Plant early garden now, if you haven't
already. This would include things such as lettuce, spinach,
onions from sets and other items that tolerate frosts. Hold off
on those warm-loving plants such as tomatoes until after May 10.
[By
JOHN FULTON,
University of Illinois
Extension director for Logan, Menard and Sangamon counties]
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