Another growing season is about to end in the more northerly parts of our country, and frosts can soon be expected in New England, upstate New York and in the Great Lakes and northern Great Plains areas. It is not too early, therefore, for you to reminisce over the past gardening season and begin to plan for next season.
A View Back At the Landscape And Garden
First, ask how the weather affected our gardens this year. In many parts of the country and particularly in the Northeast, a wet spring helped to produce lush growth on trees, shrubs and lawns. But this abundance of water was also favorable for the development of diseases caused by fungi and bacteria, and as a result many gardens may now have more than the usual number and kinds of parasitic organisms.
With such a tremendous build-up of parasites, gardeners would do well to consider what might happen to their gardens next year and do something about it before the snow flies. Measures taken now to reduce the large amount of fungus and bacterial inoculum present will go a long way towards assuring a healthy garden next year.
A Plea to Clean Up
This, then, is a plea to clean up the garden this fall. It has been demonstrated time and again that the removal and destroying of annuals and all above-ground parts of perennials that are blighted, spotted or mildewed will reduce the disease incidence materially the following year.
Among the well-known diseases that can be kept in check or greatly reduced by a thorough fall cleaning are leaf spot and crown rot of iris, leaf blotch and bud blast of peonies, hollyhock rust and phlox mildew.
The insidious black spot disease of roses can be reduced by gathering and destroying all black-spotted leaves, inasmuch as the causal fungus lives from season to season primarily in fallen leaves. Some of this fungus, unfortunately, also survives in infected canes, but drastic pruning of canes early next spring will eliminate many such infections.
Organic matter conservationists, of course, will take exception to my recommendation to burn diseased plant parts. The fact remains, nevertheless, that a great many kinds of parasitic fungi, bacteria and microscopic eelworms (nematodes) live over winter in decaying parts. Adult nematodes, which even now are blighting the lower leaves of chrysanthemums in many gardens, can survive in dried chrysanthemum leaves for as long as three years!
Unless such diseased plant parts are gathered and destroyed (I burn them) this fall, the disease-producing organisms will return to the soil and be ready to cause new infections next year.
Composting Will Destroy Parasites?
Organiculturists will argue that composting such material will destroy the parasites. This would be true if the pile were always properly made and expertly handled. But my observations have revealed that few gardeners make the right kind of compost pile and that the parasitic organisms are not destroyed in such piles. I firmly believe that the relatively small amount of additional organic matter conserved is not worth the risk of reintroducing the parasitic organisms back into the garden via improperly composted material.
Thus far I have mentioned only microscopic organisms that can be kept down by a fall cleanup. It is well to remember that many insect pests also can be thus curbed. Hollow-stemmed top growth of such plants as dahlias and corn which may harbor borers and other insects over the winter should also be gathered and burned. The tops of snapbean plants infested with Mexican bean beetle larvae and adults should be burned. If this material is thrown on the compost pile, the insects have ample opportunity to crawl or fly to hibernating spots in and around the garden.
Still another way to reduce insect damage is by practicing clean culture, for by keeping weeds under control one eliminates a common breeding place for many kinds of insects.
In order to forestall a flood of letters from organic gardeners I will conclude this brief piece by stating that compost made from disease and insect-free vegetable matter is valuable stuff!
by P Perrine – 63490
