Many gardeners are surprised to find out that, contrary to popular belief, fall is actually an excellent time to plan perennials. Gardeners and the nursery industry revolve primarily around spring planting with Mother’s day being the biggest plant shopping day of the year. However, if we dig into why we plant in the spring, we find that fall has many of the same characteristics that make spring a great time to plant and is even better in some respects.
When planting any new plant into the ground, the primary goal is to get the plant established. In other words, you want the plant to stretch its roots out into the surrounding soil, becoming anchored and able to sufficiently take up water and nutrients for growth. Early spring, after the threat of frosts, is essentially the first time this can happen in a new year. However, as most know, spring planting is a constant race between getting the roots established and hot, dry summer conditions setting in. If plant roots aren’t established by the time summer heat rolls around the plant will wilt and die without supplemental watering.
It turns out fall is almost exactly like spring from a plant root perspective. Even when the above ground material has turned brown and died back for the winter, plant roots continue growing until the soil temperatures reaches below freezing. Temperatures are typically cool and wet in the fall, perfect conditions for root growth. In addition, even if temperatures dip below freezing in the air, soil temperatures maintain warmth far longer. Soil temperatures in NW Ohio can maintain grow-able temperatures into December in warmer years. The presence of good temperatures and suitable moisture is a perfect combination for plant establishment. Instead of racing against hot, dry weather, the roots race against the soil freezing which takes a long period of sub-freezing air temperatures.
In NW Ohio, the months of SEPT and OCT are perfect for planting into your garden and in warmer years, that can be extended into early NOV. Those planting times leave plenty of time for root establishment, far more months than Spring allows. We usually start getting hot dry temperatures by JUN/JUL in NW Ohio, leaving only a month or two for the roots to get established. Comparatively, planting in SEPT will likely give you at least three soil months of root growth. As an added bonus, plants established in fall will begin growing in early spring as soon as the soil warms, far quicker than you can plant new plants. Your fall planted plants will be far more established and grow bigger that first growing season when compared to spring planted plants.
We do recommend mulching the plant in well at the time of planting. The mulch layer will hold moisture in the root space of the plant, fighting against any dry spells we may get in the fall. The mulch also serves as a kind of “root blanket” that keeps soil temperatures warmer for longer, extending your root growing season even more.
Give it a try this fall. We know you will be surprised by the results and have even bigger, healthier plants next season.