February 29, 2012
If it weren’t for the fact that it was leap year, I would be talking about it being the first of March. Figuring that it is close enough, let me tell you about a garden assignment you can do soon that will help you to have healthier plants this coming season.
There are some trees and shrubs that are prone to fungus diseases. Rose bushes immediately come to mind with their perchance for powdery mildew and black spot. Lilacs are prone to powdery mildew. Fruit trees and almost all of the ornamental flowering trees are prone to diseases. At the end of the season, the leaves die off and the diseases that have lived on the leaves form spores before the leaves die. The spores settle into the crevices in the bark, waiting for spring. The spores are like ‘eggs’ that perpetuate the disease from year to year. If you could kill off the spores, you would have less disease problems the following year. There is a spray that you can use to kill off the spores before they have a chance to “hatch”. The spray is called lime sulfur spray.
Lime sulfur spray is a dormant spray. This means that the spray must be applied to the plants before the plants begin to put out new leaves. Once the new leaves begin to emerge, the spores have begun to attack the new leaves and the dormant spray won’t work. Lime sulfur is mixed with water and it is sprayed onto the twigs and branches of plants that are prone to fungus diseases. The spray must be applied when temperatures are above 40 degrees and as I said, it must be applied before the leaves emerge. March is usually the best month to apply this spray because temperatures are above 40 degrees many days during the month. You may be able to spray in April but if you wait, April’s warming temperatures can make new leaves appear rather quickly. If you had a problem with fungus diseases last year on your deciduous plants, then this is one of the early season gardening tasks you should be performing soon.
Lime sulfur spray is not the only dormant spray that you can be doing at this time of the year. Once the temperatures get cold in the fall, many insects lay eggs on trees and shrubs. These eggs hatch out in the spring and insects begin to feed again on your plants. In some cases, the insects themselves settle into the cracks and crevices of the plant and re-emerge to feed again in the spring. You can control many of the eggs and many of the insects by applying a dormant oil spray before the new growth emerges in the spring.
Dormant oil is also called horticultural oil. It is mixed with water and sprayed onto the twigs and branches of your deciduous plants. The spray must be applied when the temperatures are above 40 degrees and if they are to be effective, the spray must be applied before new growth emerges in the spring. The oil solution covers the eggs and any over wintering adults and smothers them. Since March is a month with these temperatures, this is another garden project you should plan on doing soon.
The old saying that an ounce of prevention is worth a pound of cure really does apply to the treatment of your plants with lime sulfur spray and/or dormant oil sprays. It’s time to get back outside and do something!
Well, that’s all for this week. I’ll talk to you again next week