Don’t Prune These Plants in the Fall.
Welcome to fall, where most of your gardening to-do list involves cutting down flowers, shrubs, trees and other growing plants in your yard. Pruning is such an important part of fall cleaning that it may come as a surprise to hear me tell you to put down your clippers for a minute because there are some plants that should never be pruned, at least not in the fall.
What is the purpose of autumn pruning?
Understanding the philosophy of pruning is helpful when you are in the garden and wondering what the right approach is for a particular plant. There are several reasons to prune your plants: For trees, you can remove branches that are threatening to encroach on the street, your home or sidewalk. You can also shape bushes and trees through pruning, but this is often cosmetic.
The best reason for pruning may be to allow sunlight and airflow to penetrate the middle of bushes and trees, removing branches that cross others or grow inward. Pruning encourages branching, meaning the stem can often split into two stems at the point of pruning, and this can have a positive effect on cutting flowers and fruiting vegetables such as peppers. Finally, pruning can help your plant survive extreme conditions, such as sudden temperature changes, by allowing the plant to focus on the roots, where energy is stored, rather than using that energy to support leaves and stems above ground.
When should plants be pruned?
Typically, pruning is done when the plant is dormant and drying out, and plants go dormant at different times of the year, although winter is generally considered a safe time for most. You can prune outside of this season if necessary, for example to trim off a dangerous limb, but if you do this you will definitely be giving the plant some extra support. For example, in summer, felled trees are more susceptible to viruses and fungi.
A rule of thumb when pruning is to never prune more than one-third of the plant, which may seem like a lot, but most plants actually benefit from heavy pruning. A great example is roses, which grow well after winter when you have cut them all back.
Reasons not to prune your plant in the fall
So when should you not prune a particular plant in the fall? There are several reasons to avoid this. First, this may not be the right time to do this: a good way to guess the dormancy period of a plant or tree is to look at when it blooms. Plants flower, fruit, and then go into dormancy, so after flowering or after fruiting it is usually safe to prune. Some plants bloom in a special way, such as sunflowers; By pruning them, you deprive them of the opportunity to bloom more. Some plants don’t need pruning at all, such as annual mums. Finally, a good reason not to prune is that plants produce fruits and seeds after flowering, and wildlife feed on these fruits throughout the winter. By leaving the plant alone, you are supporting the local ecosystem.
Never prune these plants in the fall.
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Azaleas, rhododendrons, camellias: people seem to adore flowering trees and shrubs like this trio. I’ve survived all three in my yard, and my decade-long campaign to kill azaleas finally ended just this year. These trees tend to bloom once, once a year, for a few weeks, and while those few weeks are quite beautiful, then the trees begin to unceremoniously drop all those flowers. This happens in the spring, so the time to prune them is summer. If you prune them in the fall, it may well affect how many flowers you have next year. (This may be okay if, like me, you prefer not to clear the camellia flowers from your patio for a month.)
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Lilac: Lilac is a delightfully tricky character in your yard. Usually in the spring they give one flush and fill the air nearby with the most intoxicating smell on earth, and then turn back into uninteresting shrubs. Most gardening reference sources suggest that if you prune lilacs in the summer, you can encourage a second harvest in the fall. I’ve never been successful there, but you can try. In any case, the best time to thin out and shape lilacs is summer.
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Forsythia: One of the most electric plants in your fall garden. Forsythia lights up like fireworks with yellow and orange flowers. But if you want this effect, you will have to leave the plant alone in the fall.
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Blooming Pear, Cherry and Apple: These non-fruiting trees create magical snowy landscapes of pink and white flowers in late spring. The image is so beautiful that you would be a real idiot if you did anything to reduce the volume of flowering trees, like cherry blossoms in the spring. These trees need small flower buds to survive the winter, so they should not be cut in the fall.
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Hydrangea: A divisive garden plant (people either adore or despise ” hydra “), this plant comes in several subspecies, each requiring pruning at different times. Large blue and pink flowering hydras should usually be cut back in May, which means the overwintered and surviving buds are safe. Limelight hydras should be pruned after the new year as spring approaches. In the fall, only oakleaf hydras should be pruned as the flowers begin to age and change color.
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Echinacea and Black-eyed Susan: These perennial flowering shrubs can be cut down in the fall, but you should consider sparing them. The seeds in the center of these plants can feed armies of birds all winter without harming the plant itself.
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Ferns. While your green-leafed friends may look a little sad in the winter, losing their color and cheerfulness, they don’t like autumn prunes. In any case, wait to prune your ferns until late winter or early spring.
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Ornamental grasses. I like self-sufficient plants, and ornamental grasses do a great job on their own. They require no pruning or winter pruning and will survive just fine. In fact, the dying leaves simply shrivel and turn into compost, feeding the plant.