Welcome to another issue of Pest Alert. Categories for topics are as follows, H - Herbaceous plants and flowers, W - Woody Plants, V - Vegetables, F - Fruit and L - Lawns.
DISEASES
H SANITATION IS IMPORTANT. Now is a great time to clean up that vegetable and flower garden to get it ready for winter and next year's plants. Many of the most common diseases overwinter on diseased plant debris from the previous year. Careful removal of old plant stems and leaves, after they have frosted, can reduce future problems. Clean-up in the fall is preferable to spring since the plant debris will be more intact making it easier to do a thorough clean-up. If you don’t physically remove the material, plowing or spading it under will work well too. However, rototilling the garden will only bury some of the debris and leave much of it at or near the soil surface where it can start disease problems for next season. Organic waste from the garden makes excellent material to add to the compost pile.And, as long as the pile is active, the material will be safe to incorporate back into the garden next season as compost. For additional information on composting see ExEx 6004 - Composting Yard Waste and ExEx 6005 - Recycling Lawn and Yard Waste.
INSECT CONTROL
H HAVE YOU CHECKED YOUR HOUSEPLANTS? Many home gardeners routinely move some of their houseplants outside for the summer. While this can be a great way to revive plants that have been suffering from low light levels inside the home, it can also lead to some real insect and mite problems in the home this fall and winter. Houseplants are exposed to a much larger variety of insects, mites and other animals while outside. When plants are brought back into the home, some of these unwelcome pests may be coming along for the ride. Be sure to check your plants carefully for pests like aphids, scale, spider mites, slugs and other pests. Examine the undersides of leaves, new shoots and even knock plants out of their pots to look for pests. Consider isolating incoming plants for a while to see if anything shows up. Some pests may we washed from the plants with forceful jets of water or a houseplant insecticide may be used. If you want to dig up plants that are growing in your flower beds, knock most of the old garden soil off the roots then repot them using a good potting soil. Unwanted critters may be in the garden soil too. Also, potting soil is formulated to provide better drainage then a garden soil that may have a rather high clay content.
WEED CONTROL
V ASPARAGUS
can be treated with Roundup to control perennial grass that encroaches
into the bed, but do it very late in the fall after all asparagus stems have
been killed by freezing temperatures. Treat the border area to prevent grass
from moving into the patch.
L,V,H
LATE FALL WEED IDEAS. 1)
Perennials like quackgrass and field bindweed in the garden area can be
treated with Roundup. Wait
at least a week before tilling. 2)
Dandelion can be treated very late.
It doesn’t freeze easily. Recent
rain will trigger more seedlings if it warms.
3) Use Roundup to treat grass and weeds if you are
starting a new garden area for next year.
4) Burning weeds that have
been raked into a pile in the garden likely has only limited weed control value.
Most seeds have shattered and spread before they were moved into the pile and
are not affected by the fire. 5)
Check chemical storage. Glass
bottles break if they freeze. Clean
hand sprayers with ammonia and soap. Don’t
store them in a manner that hoses are bent or kinked.
6) Perennial grass is not
damaged by early freezes. Roundup
can be applied as a “border” barrier to keep grasses from encroaching into
gardens, asparagus patches, in gravel drives, around posts or trees, or in rock
borders. This can often be doe in
late October. 7)
Don’t try to use Roundup to take out invading grass in raspberries.
The new shoots will translocate the chemical into other plants in the
patch. 8)
Retreat groundivy with broadleaf spray herbicides (such as 2,4-D, MCPP,
diacamba, mixes). Two
applications in fall are usually required.
The weed grows after temperatures drop into the 20's.
OTHER NOTES
W FALL NEEDLE DROP IS OCCURRING NOW. The fall coloring and loss of inner foliage is a natural occurrence of evergreen trees, including pine, juniper (cedar) and arborvitae. The normal shedding of needles is most apparent on pines and spruce and results in numerous calls from alarmed tree owners. The critical factor is the age of the affected needle. Healthy pines retain their one- and two-year old needle while shedding their third. Healthy spruces retain their one- to six-year old needles while shedding their older ones. However, we have been receiving calls from people concerned about excessive needle loss on spruce. Generally this is due to a combination of normal interior needle drop and the loss of current and one-year old needles from rhizosphaera needlecast disease. Usually the interior needles merely turn yellow before falling, the needles infected with needlecast turn a purplish-red before falling. There is no recommended control of needlecast at this time of year. Control is initiated in the spring just as the new growth begins.
L
TIRED OF RAKING LEAVES?
Fallen tree leaves can be recycled into your
lawn with several passes using a mulching mower or regular rotary mower with the
side discharge unit blocked. Recent studies have shown that mulching of leaves
is not detrimental to the turf, and may provide a number of benefits, including
increased microbial activity, water infiltration, and improved soil structure.
Additionally, nutrients are recycled back into the turf profile.
Application of 1 lb. of nitrogen per 1000 sq. ft. in late fall will help
adjust the temporary change in the carbon:nitrogen ratio due to the introduction
of the leaf residue.
W WATERING
IS STILL A GOOD IDEA
for trees and shrubs. In many parts
of the state we have had limited precipitation during August and September.
Some people are concerned that watering during early fall will delay
hardiness and increase winter injury. While
this can occur if marginally hardy trees are provided with luxurious amounts of
water during this time, this is the exception rather than the rule. Instead, providing trees and shrubs with water will usually not delay
dormancy and can increase winter hardiness.
W WE ARE AT THE BEST TIME TO FERTILIZE TREES
AND SHRUBS. Fertilizing
after the first hard frost will allow time for the tree to absorb and utilize
the nutrients this fall. Fall
fertilizing will not result in an expansion of shoot growth, or a reduction in
winter hardiness. Fall fertilizing
will improve spring growth, however, as 70 percent of the nutrients used in the
construction of spring growth are absorbed during the previous fall.
The best tree and shrub fertilizer is primarily nitrogen with low amounts
of phosphorous and potassium, a 30-5-5 for example.
High phosphorous fertilizers do not improve winter hardiness of woody
plants nor do they promote better root growth or flowering next year. W
WHY ARE MY TREES DROPPING THEIR LEAVES NOW? We sometimes get this question from tree owners concerned that their tree is
dropping leaves before the others in the neighborhood. Evergreens will
naturally drop There are several reasons to explain this and not all of them indicate a
problem. It might be a tree species that drops leaves earlier than
the others. Black ash, Kentucky
coffeetree, and black walnut are all examples of trees that drop their leaves
earlier than most trees.
It might be due to drought. Trees in many areas of the state experiencing drought were
starting to drop their leaves in late August. If the tree is not able to provide water to the foliage it will begin to
shed the leaves prematurely. It may
be due to a fungus. A number of
trees, most notably ash, walnut and oak, have anthracnose. This is a fungus disease that results in blotches forming on
the leaves and often causes the leaves to drop prematurely.
There is no recommended control at this time other than removal of the
infected, fallen leaves. While it may not be a great help in controlling the disease,
it can provide some reduction of spores the following spring. Back to the Pest Alert page
Most recent revision Wed., October 4, 2000 by David F. Graper.
