Our rainy spring and summer has prompted a plethora of low life forms, primarily the fungal kind. Having frolicked for months, much of the damage is done and the gardener must now concern himself with late season clean-up and sanitary issues.

The apple and crabapple trees have been hard hit with cedar apple rust or Gymnosporangium juniperi-virginianae. Rust needs two hosts to complete its life cycle and the common cedar or Juniperus virginiana is the primary host, a plant found all over the state. The secondary stage of life and final spore disposal is completed on the apple and crabapple trees, evident as tiny yellow spots on leaves that mature into yellow/orange lesions with tiny black dots in the center. By midsummer, small cap-like structures with tubes become evident on the undersides of mature leaf lesions which may also be seen on the fruit.

There is no point in spraying at this stage of the cedar apple rust development, the critical factor in controlling it will be fall clean-up. Plan to rake and completely remove all fallen foliage from the area and include removal of any old fruit that remains on the tree for winter (known in the trade as mummies). Apple orchards in the state spend considerable time removing any Juniperus virginiana, commonly known as Virginia Cedar in a two to four mile radius of the apple trees to help eliminate cedar apple rust. Juniperus horizontalis and J. scopulorum are also capable of hosting the rust and completing the first cycle of spore disposal.

Apple scab or Venturia inaequalis has left many trees defoliated, crabapples have been particularly hard hit and once again the damage is done and spraying with a fungicide would be a waste of time. The spores of apple scab are spread during late April through early June (from bud break to fruit set), and once leaves begin to fall, the battle is lost. A thorough cleanup of leaves in fall, doubled with fruit removal, will function as the best preventative. Older varieties of crabapples are hardest hit, but seem to overcome their pre-mature leaf loss the following year as an abundance of new leaves return. Many of the new crabapple hybrids are resistant to apple scab.

Peony leaves may also look a little worse than usual when we have experienced a rainy start to the year. The foliage will be liberally marked with irregular brown to black spots and this is known as peony blight or Botrytis paeoniae. A common problem from year to year, our high humidity in summer allows the spores to travel easily from plant to plant. It is critical that the stems and leaves are removed in fall and this simple practice will do more than any fungal spray.

Foliage may be removed earlier but I prefer to let foliage mature as new eyes develop underground for the next year. I can vouch for fall clean-up from experience, having left a peony bed un-tended one winter, the new shoots that emerged in spring developed black stems and subsequently black buds. The entire bed was stricken, never flowered, and looked horrible the rest of the year. The same bed was carefully cleaned last winter and flowered beautifully this spring.

In conclusion: our unusually rainy seasons leave us little choice but to concentrate our efforts on fall clean-up. Old leaves should be burned, composted or bagged and removed from the property. If your making your own compost, it should be turned regularly. I would check the temperature and consider the compost safe if the internal temperature reaches 125 degrees. All of this benefits your garden.... the removal of rusts, scabs, the awful blight and by all means, don't forget the mummies!