We are all accustomed to planting in the spring. There are many reasons for this, but is it really the best time for long term plant survival? I guess that depends on a lot of things. There is no easy answer.
On the downside plant availability is better in the spring. Garden centers know then they sell most of their plant material and that is in the spring. That often means nurseries have healthier plants at their disposal then.
However, stress on newly installed plants is much less in fall around here. Growth of leaves and stems slows down and goes dormant. Trees and shrubs require less water when they enter dormancy. Watering becomes less critical than it is in spring. In short, it’s easier to take care of new landscaping.
Another reason to plant in the fall is below ground. Root growth is much more vigorous in fall. This only makes sense. Soils are warm and they take longer to cool than air temperatures because water has a high heat capacity.
Because of this, roots continue to grow well into the fall. They put down a network for water absorption that will help with the following summer’s heat stress. In our area summer stresses most plants more than winter does. Winter rarely damages deciduous trees and shrubs at all unless soils are too wet.
Plants can become stressed in winter, particularly when they are marginally hardy. I’d be hesitant to plant zone 8 plants too late in the fall. Certain evergreen shrubs or trees like eucalyptus should become established well before they must face cold winter winds. In northern climates this effect is even greater.
Another negative to planting in the fall is that the job generally looks less spectacular. Usually plantings aren’t as colorful as most flowers are dying back. Patience is definitely a virtue here. Plants will jump in the spring.
Incorporating fall flowering plants like mums, pansies and ornamental kale can spice things up. Encore azaleas have been a nice fall color addition. Most perennials like hosta, iris and daylily are best divided and replanted in the fall.
Spring flowering bulbs are planted in fall but they have no immediate impact. Bulbs should never be planed too early in the fall or they might break dormancy and not flower properly.
Around here, tulips are rarely successful over the long term as deer love them. Hyacinths generally aren’t too successful either. Narcissus species like daffodils and paper whites are another matter. They grow fabulously around here and they come back year after year. Deer won’t eat them either.
On balance, I think fall is a great time to plant, especially the basic framework. It’s also cooler and easier on the person doing the planting. For most trees, shrubs and perennials I’d say survival is better under conditions of less care.
Supplementing plantings with spring color is always a plus. Besides, after going through winter I know I’m not the only one who wants to add a little color to the picture. Spring annuals can spice up any landscaping.
Ted Manzer teaches agriculture at Northeastern High School.
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