Horticulture has two mantras that we always remind you of when talking or writing about planting. One is “right plant, right place,” which we’ll discuss later. The other is “Fall is for Planting.”
Fall is the ideal time to plant almost everything from lawns to trees. There are a few plants, however, that should be planted in the spring. Annuals are chief among them. The Morton Arboretum in Chicago also recommends waiting until spring to plant some slow to establish tree species, such as bald cypress, American hornbeam, ginkgo, larch, magnolia, hemlock, sweetgum, tuliptree, and willow. Also, broadleaved evergreens, such as rhododendrons, and narrow-leafed evergreens, such as yews, prefer spring planting. In general, plants with shallow, fibrous root systems can be planted easier in the fall than those with fewer, larger roots, according to the Morton Arboretum scientists.
The most generally accepted fall planting time is August through October, although I shy away from planting in August unless the owner is prepared to water frequently. August is often very dry and hot around here. Then someone throws a switch right after Labor Day and days continue to be warm but nights cool off. When air temperatures are cooler than soil temperature, plants add root growth rather than top growth, resulting in better developed root systems in spring.
I have one caution. Conifers should be planted earlier than hardwoods. So, I recommend planting conifers in September and hardwoods in either September or October. You can plant hardwoods right up until the ground freezes but there won’t be time for the roots to get as well established as they would if planted in September or October.
Many nurseries and garden centers order new plants for fall planting. You’ll be able to tell which are new and which survived the summer drought. If you’re looking for a bargain, you may be able to negotiate deep discounts on the survivors. Personally, I don’t like to do that. I rather pay list price and get new stock.
Plant the same way in fall as you do in spring. Select a planting site whose conditions are right for the plant you select. Remember – right plant, right place. Dig the planting hole two to three times bigger around than the rootball, but only as deep. If potted, remove the plant from its pot. If balled and burlapped, remove the wire basket or rope but leave the burlap around the ball.
Set the plant in the hole and backfill, stopping occasionally to press the backfill to fill in any air pockets. Don’t pile soil up against the trunk. Finally, water well.
It’s good to mulch any new planting, but it’s especially important in fall. The mulch will help moderate the temperature shifts during the winter. Spread 2 to 3 inches, but don’t pile it up against the trunk in a mulch volcano. Before winter, add another inch of mulch, but be prepared to remove that in spring.
This year has been a year of extremes, from record cold to record heat, from record rainfall to near drought. I won’t even try to predict what kind of fall and early winter we are in for, so I suggest that you do your fall planting early so that your new acquisitions can become well established while weather conditions remain seasonal. That way, they’ll be better able to withstand nature’s winter assaults.