Why Plant in the Fall?
By Brian Grubb, Horticulturalist
For gardeners and plant lovers, all seasons are a time to rejoice, but fall is a special time in the hearts of many for planting. It does not take much to consider some of our more iconic garden stand-outs that are routinely fall planted. Take Allium or any of your favorite fall-planted geophytes, like Tulipa or Narcissus. So, what are the real benefits of fall planting, and would I personally recommend this practice, as a seasoned horticulturist?
Every year, I look forward to fall in my own garden, and to the benefits of planting. I love being outside in the fall. I am a lazy gardener. I disguise this in the mantra of '“highest quality, least effort.” Fall planting fits into this category. There are numerous reasons to fall plant. Let us use the example of native trees, shrubs, and herbaceous plants for fall planting, although any hardy, perennial, woody, or herbaceous plant will fit this category.
One of the greatest benefits of fall planting is warm soil temperatures, which are ideal for establishing new transplants. In combination with warm soil, we tend to have cooler air temperatures. This combination places less stress on the leaves and stems of a plant but allows for roots to maximize growth from the warmer soils compared to spring. Roots can maintain activity into November, or until the ground freezes. Establishing plants in the ground in the fall maximizes this root growth. Similarly, in spring, plant roots will begin to grow before shoot growth. Having these plants already in the ground provides a jump on spring growth and establishment.
Insect pressure on plants tends to be lower in the fall. Consider aphids, beetles, and borers. These insect life cycles tend to be completing in the fall months, so pest pressure to our plants can be minimized by fall planting. This is also true for weed control.
Many native perennial plants are grown as one-year-old seedlings. Most of these require at least two years before they will flower—or at least a cold treatment, known as vernalization. Taking advantage of fall planting will allow your one-year-old native seedlings to receive this vernalization and flower the following spring.
For me, the choice is always easy. As a rule of thumb, I am always planting annuals in the spring, around Mother’s Day. I plant most, if not all, my perennial plants (woody and herbaceous) in the fall. I await the winter in positive anticipation of things to come. It is a rite of spring for me as a professional horticulturist. It is just engrained in the way I do my work. Of course, there are always exceptions, and I can be found moving and planting almost any time of year. Fall for me is the best time for transplanting, too.
Final Tips for Success:
Provide sufficient time for roots to establish. I personally do not like to plant too much past Halloween, but planting into November is reasonable.
Make sure your plants are healthy with developed buds, stems, and roots. Otherwise, a more protected overwintering site may be appropriate.
Mulching will help protect against frost heaving in the event roots are not anchored by the first few hard freezes.
A note from the CGC: If you’d like to plant in the fall, check out our online Fall Native Plant Sale!