October 11, 2017
Many of the vegetable plants and many of the annual flowers that you planted in the spring are beginning to fade away. If you look closely you may find that some of the plants will be infected with some type of fungus disease. Leaves will have black or brown spots that may expand into leaves turning completely brown or black. Leaves may be completely covered with a white powdery film. Once the fungus attacks, the leaves eventually die. As the leaves die, the fungus disease forms spores. The spores are like eggs. Spores sit on the soil, waiting for spring. Come the spring, when new plants go into the ground, rain or watering of the plants by you, allows the spores to splash up on the leaves and the spores begin a new generation of the fungus disease.
One way to minimize the spread of the fungus diseases from year to year is to clean up all of the dead plants and leaves and dispose of the diseased plants and any leaves that may have fallen on the ground. If you don’t clean up your garden, be it a 20 foot by 40 foot plot of land or a large planter, you are allowing fungus diseases to over winter and start the mess all over again. People often ask me if they can compost this type of dead plant material into their compost pile. My feeling is that most compost piles don’t heat up enough to destroy the spores. My thought is that if you can dispose of these plants with the municipal pick up of leaves, you are getting much of the cause of next years’ fungus diseases out of your yard.
Once you get the planting bed cleaned up, you should add some lime to the soil and then plant a cover crop of winter rye seed onto the surface of the planting bed. The winter rye will sprout and form a grassy mat that will hold the soil in place over the winter. Come the spring the winter rye is tilled into the soil, adding valuable organic matter to the soil.
Over the last 2 weeks, many people have come into the store with leaves from their maple trees. The leaves have these raised black spots that look like globs of tar. The name of this plant disease is tar spot. Tar spot usually begins in the spring when the leaves are emerging during prolonged periods of rain. It is the constantly wet leaves that get the tar spot going on your trees. Tar spot usually doesn’t kill a tree and it is not very often that it shows up year after year. I have seen rainy springs where the tar spot is so bad that by July every maple leaf has fallen off the trees. Come the following spring, normal conditions appear and the tar spot doesn’t show up at all. Since you never know from year to year what the early spring will bring us is a giant unknown, it is best to rake up the infected maple leaves and dispose of the leaves.
Well, that’s all for this week. I’ll talk to you again next week.