Spring isn’t the only time to plant
As I count the days until spring, I find myself thinking of all the things I want to do in our yard and gardens as soon as the weather begins to warm.
Each year, there are so many that I create lists that I share with my husband, who patiently goes along with my spring gardening projects, which often require his backhoe. As a devoted and sometimes obsessed gardener with several acres, these lists can get pretty long. I learned years ago that, no matter how hard I tried, we often couldn’t get everything done before spring turned to summer. That’s when I discovered the benefits of fall planting.
Some gardeners may find it surprising to learn that fall, like spring, can be an ideal time to plant. The cooler temperatures during the fall season mean less stress on new plantings as they begin to take root in their new locations. Fall rainfall here in central Pennsylvania tends to be ample, allowing roots to soak up moisture without the need for extensive supplemental watering. Root systems continue to develop until the air temperatures drop into the 45 F range, even though top growth has become dormant. When planted in the fall, plants have an opportunity to become established before the spring growing season begins and can often out-perform spring transplants which will need to use their energy to build root systems.
I have reduced my spring “to-do” list by completing a significant amount of planting in the fall. Perennial beds which have become too crowded over the summer are dug up, divided and replanted in early fall, providing plenty of plant material for new beds. This has saved me a considerable amount of time in the spring, when I’m busy with so many other projects. It has worked very well for irises (Iris spp.), daylilies (Hemerocallis spp.), Solomon’s seal (Polygonatum spp.) and numerous other perennials. An added bonus is that these fall transplants have a head start the following spring.
Many, but not all, trees are suitable for fall planting as well. Deciduous trees (those that lose their leaves in winter) are often good choices for planting in the fall. Some popular examples for our area include maple, crabapple, sycamore, redbud, and linden.
On the other hand, evergreens, such as pine, spruce, and fir and not recommended for fall planting. Because evergreens do not lose their leaves or needles in winter they are more susceptible to drying out when strong winter winds arrive and the ground is frozen, making them unable to pull water up into the top growth of the plant. Deciduous trees that have thick, fleshy or tap roots or are slow to establish, such as magnolia, oak, and birch are also not suitable for fall planting.
Deciduous shrubs are also well suited for fall planting and the choices are nearly endless. As with trees, however, evergreen shrubs, especially broad leaf varieties such as rhododendron, boxwood, and holly, are not recommended for planting in the fall. More detailed information of fall planting of trees and shrubs is available from Iowa State University at https://hortnews.extension.iastate.edu/1997/8-22-1997/fallplant.html
Fall is an ideal time to plant most spring-flowering bulbs. That’s because, in order to flower, these bulbs require a period of cold temperatures called vernalization. Without that cold period, which can extend from weeks to months depending upon the bulb variety, the plant will not flower. Many of our most-appreciated spring flowering bulbs, including tulips, daffodils, and hyacinths require vernalization. By planting them in fall, they are able to experience the extended periods of cold they need to put on a beautiful show of blooms in spring.
Another candidate for fall planting is turfgrass. According to Lawn Management through the Seasons, a Penn State publication by Peter Landschoot and John C. Harper II, “Late summer to early fall is usually the best time to establish a new lawn from seed.” That timeframe gives the lawn two seasons of cool temperatures before it will need to withstand the heat of summer.
There are a few things to keep in mind when planting in the fall. Make sure plants receive sufficient moisture. If rainfall is inadequate, supplemental watering is necessary. Here in central Pennsylvania, mid-September through mid-October is usually a good timeframe for fall planting, although the possibility of extreme weather conditions, such as extended heat or drought or a very early onset of winter weather are always possibilities to be considered. Planting at least six weeks before a hard freeze is essential. Adding a layer of mulch around fall plantings can provide some extra protection through the harsh temperatures of winter.
While fall planting can benefit many plants, it also can help busy gardeners by providing an additional window of time in which to get everything planted.
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Debra G. Burrows, PhD is a retired Penn State Extension Educator and certified Master Gardener. She can be reached at firstname.lastname@example.org.