By Dan Eskelson
The recent cool temperatures and welcome rains suggest the end of summer; I know many are saddened by the change, but I will not miss the record heat – and the smoke – of this year’s season.
Though yard work is usually not at the top of the priority list this time of year, autumn and fall are important seasons for our gardens. Late season chores may not yield immediate, obvious results, but they are very important for our gardens’ winter hardiness and long term health.
One of the most neglected fall garden chores is watering…once the weather cools, we often forget that our plants still need water. In areas that freeze hard in the winter, late season watering is especially critical because roots will be unable to take in moisture when the soil is frozen. Be sure your gardens are well irrigated shortly before freeze up, whether by deep, soaking rains or by your irrigation system.
Another important fall garden chore is caring for your lawn. Both natural and high maintenance lawns can benefit from fall aeration. When soil is moist but not saturated, aerate with a hollow tine coring machine, leaving the cores lying on the surface – subsequent rains/irrigation will “dissolve” them. Fall timing for this operation is ideal, since aesthetics are not as important now as in the spring. Fall and winter moisture will soak deep into the aeration holes, encouraging deep roots.
In my opinion, the most beneficial lawn fertilization is applied in the fall. When the mean temperature is 50 degrees – e.g. daytime high = 60, nighttime low = 40 – leaf blades stop growing, but roots are still active. Fertilizer applied during this average temperature range will feed the roots only and insure hardiness over winter with plenty of reserve for spring. Fall fertilization of turf often eliminates the need for spring fertilizer and resulting surge growth. Turf grows fast enough in the spring without additional food!
Add more spring color to your yard by planting bulbs. Tulips, daffodils, alliums, crocus and others are planted in mid-late fall. Improve the soil with compost and bone meal, or other phosphorus source, to encourage flowering.
In the perennial bed, cut back plants to a one inch stub after a hard freeze. This will eliminate many insect and disease habitats while still marking the plant location for your spring work. Remove all weeds before seeds mature. If frost heaving is a problem in your yard, mulch perennials with 4-6 inches of coarse organic material – wait until just after a hard freeze to mulch. It’s not the cold that causes the problem, it’s the alternate freeze and thaw that pushes the roots out of the soil.
Similarly, in the vegetable garden, remove spent crops and weeds. Because our spring weather is often cold and wet, build new planting beds in the fall so early spring seeding can be accomplished without the need for much soil work. This can lengthen your season by several weeks. Like ornamental bulbs, garlic is best planted in the fall.
Special winter protection may be required for some plants…the trunks of fruit trees, maples, and others with thin bark can be protected from rodent damage with trunk collars. I like the white, spiral-type collars, since these also reflect the sun’s heat, which can cause bark splitting in late winter and early spring.
Fall is a great time to reflect on the season’s successes and failures. Nature has given us some time to appreciate and study our gardens without the hectic schedules of spring and summer. Enjoy your fall garden work!
As the gardening season wraps up, Dan will be taking a break from his bi-weekly column. Look for Garden Corner again in the spring.