Is fall really a great time to plant trees?
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
In numerous extension bulletins and certainly in nursery sales advertising, we hear that “fall is the perfect time to plant trees.” Nevertheless when I look back on the planting disasters I’ve been called in to inspect over the years a disproportional share (I’d say by a factor of two or three to one) are fall planting jobs.
What gives? Well, the notion that fall is a great time for planting is built in a faulty premise, at least for this part of the country. Probably the most commonly cited reason for fall planting is that trees grow a lot of roots in the fall. This assumes that since there’s no shoot growth occurring, trees automatically shift reserves below ground. There is certainly a “pecking order” of carbohydrate distribution within a tree based on relatively strengths of sources and sinks. But there’s one factor that trumps all others: temperature. Soil temperature is the biggest driver of root growth. As temperatures decline in the fall, new root growth essentially ceases. For trees that are well established, this is no problem. For trees that have just been transplanted and need to re-establish root-soil contact this is a tough row to hoe. Throw in a tough Michigan winter and the tree’s facing an uphill climb.
In most cases, planting failures have multiple causal factors. Even if trees are planted in the spring, they may have still experience problems. My point is that a more accurate statement is “fall is an OK time to plant trees;” not the best time or even a great time. In certain parts of the country, fall probably is the best time to plant trees. Washington State University Extension Specialist (and fellow Garden Professor blogger), Linda Chalker-Scott is adamant that fall is better than spring planting in the West where plentiful fall rainfall is as predictable as dry, hot summers. For the Midwest, however, where cold soil temperatures can limit new root growth in the fall, I will stick to my guns and recommend spring planting if there is no compelling reason to plant in the fall.
For spirited debate on the merits of fall planting in various parts of the country, check out the Garden Professors blog archive https://sharepoint.cahnrs.wsu.edu/blogs/urbanhort/archive/2010/05/24/is-fall-really-a-great-time-to-plant-trees.aspx
Dr. Cregg’s work is funded in part by MSU‘s AgBioResearch.