After a long, hot summer, the recent early rains are welcome as our gardens begin their fall decline into dormancy. We still have lots of time to make sure they will be ready for next year’s growing season.
Even with good watering, most gardens suffered in the lengthy days of 90-plus degree temperatures. Some plants began losing leaves early, lawns turned brown and evergreen trees of all sizes began dumping excess needles early. These responses took a lot of energy away from the plants. Their reserves are low as they go into winter. In the spring that lack of reserves could show up as delayed dieback and weak growth.
While the early rains are helpful, make sure stressed plants are getting water deep into their roots. Dig a few test holes 8 to 10 inches deep around your plants. If the soil is still dry at the bottom of the hole, give them an overnight soak with some soaker hoses wound through the plants. This is particularly important for shrubs and trees that were on the edge of sprinkler system or had no irrigation at all. In mid-September, the WSU Spokane County Master Gardener Plant Clinic saw several Douglas firs with significant needle dieback because of a lack of water.
To further help shrubs recover, apply a slow release fertilizer to the area around the drip line of the plant. The roots will take up the nutrients and store them for spring growth. Apply a 2-inch layer of good compost over the root zone when you finish raking up the leaves and needles and the ground is bare. Along with feeding the plant, it will also help control cool season weeds like bulbous blue grass and chickweed that will pop up over the winter.
Kentucky bluegrass lawns tend to go dormant when the temperatures go above 90 degrees. This year most of our lawns began going dormant in mid-July instead of the usual early August. Again, this robbed the grass of time to grow healthy roots. With plenty of early rain this fall, it’s a perfect time to put down a slow release organic fertilizer to bolster the roots as they begin going dormant. They will store the extra nutrients and be able to begin growing vigorously next spring.
Along with your fertilization program, it is also a good time to do some lawn weed control and reseeding to get the lawn ready for next spring. If you had small weed issues, simply hand dig the few offenders. If you had large patches of weeds, it is best to treat those areas with a herbicide and then over seed the area with new lawn seed. The herbicide will kill the weeds and the grass seed will be incorporated into the top layer of the soil by the freeze-thaw cycles over the winter and come up in the spring to out-compete the weeds.