University of Vermont
Department of Plant and Soil Science
Summer News Article
CONTROLLING SLUGS AND OTHER JUNE GARDENING TIPS
Leonard Perry, UVM Horticulturist
and Charlie Nardozzi, Garden Consultant
Controlling slugs and mosquitoes naturally, raising containers for
better drainage, and fertilizing warm-season vegetables are some of
the gardening activities for this month.
With the summer weather upon us, slugs in some areas (particularly
wet ones) may seem everywhere. They eat holes in the leaves of many
vegetable, annual, and perennial plants. One of their favorites is
one of gardeners’ favorite perennials—hostas. There are many
chemical and non-chemical controls for slugs, including one that
contains iron phosphate as the active ingredient. The slugs eat the
pellets and die, yet the iron phosphate doesn't harm other wildlife
or the environment (it may harm earthworms). Avoid other toxic
baits, as children or pets may eat them with serious consequences,
There are many other methods to trap slugs, such as under boards or
in wet newspaper rolls in the garden. The more famous trap is
saucers of beer which attract them and in which they drown. Some
gardeners swear by coffee grounds, sharp gravel or egg shells
sprinkled around plants, while others report mixed results at best.
Yet the caffeine from a weak coffee spray often deters slug feeding
on leaves. You can buy copper strips or products to place around
choice plants, just for this purpose. These supposedly repel slugs
through creating an electrical charge as they cross.
To allow good drainage in your container plantings, raise the pots
off the ground or deck so water can seep out the drainage holes.
This also will reduce the staining that can occur when pots sit
directly on wooden steps or a deck. You can purchase pot feet from
garden supply stores, or make your own using flat stones of similar
size, rubber bumpers from the hardware store, or even old checkers
from the game you never play anymore. Anything that will elevate the
pot a bit should work. Bricks work well for containers on the
Examine your yard for areas with standing water, such as old tires
or upturned garbage can lids, and dump them. Mosquitoes breed in
these types of places, so by removing them you'll get a head start
on controlling the pests. The larvae that hatch from eggs need
about 10 days to feed on organic matter in the still water. Use
"mosquito dunks" in ponds or rain barrels. These disks contain a
specific strain of Bt (Bti, a natural bacterium) that controls the
mosquito larvae. Covering rain barrels with a fine screen may be
all that’s need to keep mosquitoes from entering and laying eggs.
Sow new crops of beets, carrots, and summer lettuce to extend the
harvest. You don't need much space, you can sow a border around
other vegetables. If possible, choose a spot that's partially shaded
by taller plants for sowing lettuce, so it will stay cooler.
Tomatoes, squash, and cucumbers can use some nutrients now, so
scratch some granular fertilizer into the soil around plants or in a
shallow trench alongside a row. Do this when the soil is already
moist, and then water it in.
Where does one begin when choosing a hosta among the hundreds
available? You might start with the hosta of the year, named each
year by the American Hosta Growers Association
(www.hostagrowers.org). For 2017, the winner is ‘Brother Stefan’--
medium sized (just under two feet high and three feet wide), with
crinkled gold leaves and wide irregular green margins. White blooms
appear in early summer.
Nardozzi is a nationally known horticulturist, author, gardening
consultant, and garden coach; gardeningwithcharlie.com).
Return to Perry's Perennial
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