Unbelievably, we are nearing the end of August and entering September, the beginning of meteorological autumn. Where have the days and weeks of summer gone? If you are like me you did not get all or even most of the things done in your gardens that you enthusiastically planned last spring. Yes, part of the reason for my lack of progress was of my own making, traveling and hosting a number of visiting friends and family. The other part was the unbearable heat and humidity (and air quality) in June and July that made it nearly impossible to work outside for any length of time. And because of the continuing drought I spent most of my time outdoors watering. Interestingly, while reviewing the past few years of columns I’ve written for September issues I mention June and July as being unbearably hot and dry, but August bringing more rain and cooler temperatures. I am beginning to see a pattern here and if the pattern of the last few years continues, September will be an ideal gardening month.
As September approaches, our yards and gardens still require and deserve a lot of attention. There many things that can be done in the, hopefully, cooler fall months of September and October, even November.
Flowers: Deadheading your annuals will make them continue to bloom until frost, but it is important to deadhead your perennials as well. This will conserve plant energy for next year rather than it being used for seed production. It is ok to cut back any yellow or brown foliage on perennials but leave the green so it can continue to produce carbohydrates to store in the roots for next year. Now is a good time to divide and transplant perennials, as well as to plant new ones. The added bonus to fall planting is that many of the garden centers will have perennials on sale. Transplanted and newly planted perennials will need 3 to 4 weeks of mild growing conditions to get established and ready for dormancy so be sure to plant by the end of September.
Lawns: The best thing you can do for your lawn this fall is water, if our August rains do not continue. Your lawn requires 1 to 1 ½ inches of water per week. How often to water is dependent on the amount of rainfall we get and on the soil type. Sandy soil drains readily so that much of the water will drain down to below the root level; in this case it is better to water ½” 2-3 times per week. Loamy or clay soil retains the moisture better so a weekly soaking of 1” will suffice, just be sure that the soil is not so saturated that water is standing on the lawn. If at all possible, water in the mornings to reduce the potential of evaporation in the heat of the day and to prevent turf disease.
Mid-August to mid-September is also the best time of the year to reseed or overseed a thin lawn. September is a good time to dethatch, power rake or core aerate your lawn; turf will need a good 6-8 weeks to recover from these procedures so be sure to do it early in the month. And Labor Day weekend is good time for an early fall fertilizing — if you don’t mulch and leave your clippings on the lawn.
Trees and shrubs: Water is also critical for trees and shrubs as they are preparing to enter dormancy. They require 2” of water per week especially for trees that are younger than 5 years. Once again, high temperatures will contribute to soil moisture evaporation so they may require even more water if we experience hotter than usual weather. Remember to water as far out from the tree as the canopy, as the roots grow that far out from the trunk. (You may already be doing that if you are watering your lawn.) Continue to water your trees and shrubs until the ground freezes, especially evergreens as they need plenty of moisture to retain their green needles through the winter. Fall is also a great time to plant new trees and shrubs because cooler temperatures put less stress on them, and they are able to develop their root system and become established quicker. If you do plant a new tree or shrub, be sure to mulch over the root system, but not touching the trunk of the tree.
I, for one, intend to spend as much time outdoors as I can this fall, before the eventual closing of the doors and windows. We may be weary of yard work right now but attention to your yard and garden in the fall will yield big rewards next spring. There will be more tips for the fall in next month’s column.