Fall is the best time to fertilize shrubs and small trees that have been in the ground for at least a year. A few handfuls of slow-release nitrogen fertilizer under the dripline in the next few weeks will be greatly appreciated by those plants.
An application of herbicide in the spring is not always totally effective because various weeds have different times when they break dormancy. Herbicides, sold for use on lawns, only work if the target weed is actively growing, rather than sitting dormant. While the spring application of herbicide will deal with many of the common pests such as dandelions, it is not so effective on the late starters such as creeping Charlie, oxalis and others because they don’t really begin growing until long after the spring herbicide has been applied. On the other hand, the whole blooming family of broad-leaf weeds is growing very well right now in October, so now is the best time to strike.
Most broadleaf herbicide products have a mixture of two or three of these chemicals: 2,4-D, dicamba, MCPP and triclopyr. You can get good results with any combination of these herbicides over the next two or three weeks.
Fertilizer applied to the lawn in late fall is used by the grass plants to build more roots and to store food for next spring. It does not cause the foliage to grow any more this season. A side benefit is that the lawn is likely to stay green longer into the winter months.
The timing of the late fall fertilization is very important. You want to apply the product just as the lawn no longer is growing enough to need any more mowing and is still green. That will be about a month or more before the ground really freezes. In Metro Detroit, the time for late fall fertilizing is the first two weeks in November.
You are looking for a product that is high in nitrogen (N), low in phosphorus (P) and high in potassium (K); the three NPK numbers will be something like 15-4-12. Some of the fertilizer companies have products with the word “winterizer” somewhere on the label. These are appropriate if they have slow-release nitrogen and are used according to the label in terms of how much you spread. Avoid the “weed and feed” products. They are convenient but not very effective in killing weeds.
My organic fertilizer of choice is either Espoma Organic Lawn or Milorganite. They are both granular and easy to spread. They can be found at English Gardens, Bordine and many other garden centers.
Jeff Ball, a Metro Detroit free-lance writer, has authored eight books on gardening and lawn care. You can visit his yard care Web site at http://www.yardener.com . E-mail him at firstname.lastname@example.org.