At the end of the season, cleaning up tree fruit and small fruit plantings will yield benefits in the future. Consider taking the time to prepare your plants and trees for the winter.
Pick up fruit
Unharvested and rotting fruit on the ground provides overwintering quarters for insects and diseases. Take time to pick up these fruit and dispose of them. Apple maggots are a perennial problem in apples. Research at the University of Massachusetts has shown that one of the best ways to control this pest that will attack next year=s crop is to remove fruit on the ground this fall. Apple maggots spend the winter in old fruit and emerge as adults the next spring to attack fruit. Reducing populations this fall will make control next year much easier.
Rake up or mow leaves
Apple scab is the most devastating disease on apple trees. Fruiting bodies of this fungus overwinter undetected and unseen in the leaves and litter under a tree, providing the inoculum (spores which initiate growth of the fungus) in the spring to infect trees as leaves and flowers open. Research at the University of New Hampshire has shown that if the inoculum is reduced in the fall, infection pressure is substantially reduced the following year. Leaves should be either raked up and disposed of, or mowed into small pieces, which speeds decomposition and destruction of inoculum.
Control mice
Mice cause more damage to plants than most people realize. During the winter there is very little food available for mice. The succulent bark of fruit trees is a favored alternate food. During years when there is a heavy and continuous cover of snow, mice can travel with relative safety undetected under the snow in search of food. If there is a high population of mice and there is a snow cover, the chances are great that trees may be either damaged or killed. Mice eat the outer bark of trees which contains the transport system that carries food manufactured in the leaves down to the roots. Trees that are completely girdled starve to death the following year because of a lack of transport of food to the roots. Mice also eat tree roots. Damage from mouse damage to roots is less obvious but, when severe, can also kill trees.
Strategies for controlling mice
There are several strategies that a home gardener can use to prevent mouse damage.
- Mow grass and ground cover as low as possible under and around trees during the fall. Research has shown that mice migrate out of areas with little or no ground cover because they are exposed to attack by predators such as hawks and cats.
- Trunks of trees can be protected from mouse damage by enclosing the trunks of trees with an 18 inch high piece of hardware cloth. This prevents mice from getting to the bark. Make sure that the hardware cloth completely encloses the tree trunk.
- Create bait stations. Place old shingles, corrugated iron, old boards, or other large flat objects in several places on your property near fruit plantings. This should be done in September. Mice seek shelter under these objects, and often use these as part of their trails or runs as they move around your property. Once activity is detected, you can place mouse bait in the runs and then place the shingle or other object back over the run. The advantage of this method is that you are placing the bait where mice travel and live, yet you protect other nontarget animals and birds that might eat the bait if it were exposed on the surface.
- Remove mulch. The use of mulch during the growing season is an excellent horticultural technique to increase plant growth and preserve moisture. However, it harbors and protects mice. It is important to pull mulch away from trees early in the fall. This slows the growth of the trees thus allowing them to acclimate to cooler conditions and gain winter hardiness. It also eliminates a hiding place for mice.
Mice can cause extensive damage to plants. Fall is the best time to reduce populations and reduce injury. An added benefit of this is that if you reduce the mouse population you may have fewer mice finding their way into your house this fall when the weather turns cold.