Fall is for planting. A little slogan that nurserymen coined a number of years ago to promote fall nursery business. About 30 or 40 years ago our industry was heavily weighted towards planting in the spring and with good reason. Product could be dug dormant and planted in March through June, receiving beneficial spring rains and the new plantings would have seven or eight months to begin to establish themselves prior to winter. This meant a higher survival rate and healthier landscapes. Our industry has changed significantly over the last 30 years.
Larger trees are now being grown in 25gal or larger containers and these trees rival their balled and burlap counterparts in quality. New techniques and products have enabled nurserymen the ability to dig trees when it was not possible 15 years ago. Products such as bioplex, applied to the tree ensure much greater success in digging while a tree is in full leaf. Trenching trees in June or July and flooding them with water and allowing a week or so to dig enabled nurseries to dig even difficult trees during times when trees should not be dug. Just recently we shipped Sophora (Japanese Pagoda tree) and Zelkova Green Vase that were slow dug and treated with bioplex. These trees were 3” Caliper so they were fairly significant. The Zelkova had been root-pruned (trenching around a tree at an earlier time to promote greater root growth and minimize shock). In a perfect world I would not recommend this be done, but the customer had a deadline and we went to a reputable nursery that would do the job right. The onus now falls on the customer for proper care after planting and that is a critical part in this equation.
So what’s all this have to do with fall? In times past, the availability of product and thought process dissuaded folks from planting in the fall. In actuality fall is a great time to plant with a couple of caveats (get to those in a bit). Towards the end of September plants start shutting down or go dormant. This becomes a great time to dig as we do not shock these plants once they are sleeping. The root system continues to grow. Air temps. get cooler, but soil temps. remain constant, allowing for root growth well into November. This is a real good recipe for success. There’s no question that availability and selection are greatest in the spring, but the palette remains pretty broad in the fall. If material is above ground and healthy you run no risk of transplant shock and the same is true for container grown plants. Be familiar with fall hazard plants, meaning plants that are a major hazard to dig in the fall. Plums, cherries and oaks, to name a few are pretty risky in the fall and I would avoid having them dug if possible. However, if they’re grown in containers no issues. We stop bringing in Leyland cypress around the beginning of August as this plant will not establish itself prior to the winter and you run the risk of high mortality, the same holds true for skip laurel and cherry laurel.
How late can I plant? The million dollar question. I have shipped white pine in January and had success, but of course you run a much greater risk. Generally speaking, if you plant through the month of October you should be in good shape. Dig an adequate hole for the plant and amend with organic matter. When possible, we highly recommend products which stimulate root growth. Of course you should put down at least 2” of mulch to keep moisture in and help stabilize soil temperatures. Here is the key, water. Even though a plant may have lost its leaves or evergreens have gone to sleep, they still need moisture in the roots. Fortunately, with cooler temps. soils hold moisture longer so watering may be less frequent, but keep the soil moist. Moisture loss retardants on evergreens can be helpful (ie. Wilt pruf and Vapor guard), but be mindful of the label as there are some plants like blue spruce which should not be sprayed as they will off color.
There are exceptions to every rule as this past winter so rudely pointed out. You can successfully plant in November and December, but September and October are far more favorable times. Know your fall hazard plants and exercise common sense. Broadleaf evergreens planted late have a far worse chance of survival than when planted in early fall. Deal with a knowledgeable nursery or contractor as they can steer you properly through the do's and don’ts while planting in the fall. One last point. I could probably come up with a number of caveats when planting in the spring as well, so if the plants you seek are available and you follow some simple rules there is no reason why you shouldn’t plant away!!!!!