Should You Plant Perennials This Fall?

There’s nothing better to take some of the chill off winter than to fritter away the long nights planning for spring gardens. But is spring the best time to be planting long-lived plants like trees, shrubs and other perennials? There’s a strong case to be made for fall planting of many beloved landscape plants.

— Fall planting advantages.

— When is it too late to plant?

— Mulch is vital for success with fall plantings.

— The secret sauce to fall planting success.

[Read: Ways to Prepare Your Lawn and Garden for Fall]

Fall Planting Advantages

Although short-lived plants like vegetables and bedding annuals have to be planted in the same season that you hope to see results, the same isn’t true of longer-lived plants like trees, shrubs and perennials. In fact, there’s a strong case for fall planting over spring planting for many species. Not only does it give the plants more time to develop, there’s a lot less to battle in the way of vegetative competition or insect pests.

“For many perennials including trees and shrubs, planting in the fall gives them a head start because even though the air temperature is cooling, the soil is still warm compared to the temperature of soil in the spring,” says Dr. Clydette Alsup-Egbers, associate professor of environmental plant sciences at Missouri State University in Springfield, Missouri. “Fall soil temperatures let the plant’s root system get well-established. It’s not actively growing leaves or flowers, so it can send its energy toward roots. Another reason to plant in the fall is the plants will have less competition from weeds for water and nutrients.”

Not every plant is going to be well-suited for fall planting. According to Alsup-Egbers, ornamental grasses, summer-blooming perennials and evergreen trees and shrubs tend to do best when planted in the spring. This is often because these plants struggle more with the adverse conditions that come with that first winter. It pays to understand what it is that you want to plant and whether it will do better trying to get settled during your local winter or summer, both stressful times for many plants.

“For Western gardens that have high summer temperatures, planting perennials (including trees and shrubs) in the fall gives plant roots time to establish before the summer heat,” says Sierra Laverty, plant health consultant and owner of Idaho Plant Doctor in Boise, Idaho. “Really this is all about understanding the biggest environmental and climatic stressors that plants in your area face. Is it 115 degrees in the summer? Fall planting will give a plant time to establish before facing this stressor. Is it -30 in the winter? It may be better to plant in spring.”

[READ:10 Fall Home Decor Ideas From the Pros]

When Is It Too Late to Plant?

Although fall planting can greatly benefit many species of plants, there’s always a point of no return. At some point, the plant you’ve chosen isn’t going to get a lot of the benefits of a fall planting. Obviously, it’s quite the trick to plant anything once the ground has frozen for good, but there’s a lot of time between the first blush of fall and the coming of true winter.

“Ideally, planting before soil temperatures fall below 60 degrees is best,” says Jeremy Lowe, director of agronomy at Chorbie in McKinney, Texas. “Planting fully dormant plants can be less desirable, with bare root plants being an exception, simply because purchasing a dormant perennial does not always allow for the selection of the best nursery stock — it may appear that you are buying nothing but a bucket of dirt. Purchasing plant materials prior to full dormancy will allow for the selection of high-quality nursery stock for most perennials and deciduous shrubs.”

However, further north, you may find that your time is extremely tight if you’re looking for perfect planting conditions. Although planting prior to dormancy is ideal, it’s not a hard and fast rule for every kind of plant, especially those dormant buckets of dirt.

“Trees and shrubs can be planted before or after dormancy,” says Alsup-Egbers. “I purchased three maples several years ago and the nursery planted them in mid-December. They have flourished.”

Although you may not need to worry too much about the timing of the planting for the plants’ sake, there are still a few things to watch for the later you get into the fall season to protect them from the effects of the cold.

“If you plant too late into the fall, you may see ‘frost heaving,’ ” says Laverty. “This is where plants will dislodge up out of the ground, exposing their roots to the winter air. You can avoid this by planting early in the fall before a hard frost, by monitoring plants and tapping them back into the ground, and by adding a layer of wood or leaf mulch around their base.”

[READ: How To Overwinter Tender Plants]

Mulch Is Vital for Success With Fall Plantings

Planting your trees, shrubs and perennials in the fall is no guarantee of success for your spring garden. A lot will come down to how well you’re prepared to care for your plants through the cold weather. Mulch is practically a given, but some other treatments can also help.

“Proper mulch to conserve moisture and adequate watering, especially prior to hard or sudden freezes, are the most important factors to mitigate damage due to cold weather,” says Lowe. “Additionally, using a high-quality source of potassium like Texas greensand can help regulate water use in the plant and provide additional protection from cold weather.”

Mulching a plant is more than just scattering wood chips or other organic materials around on the ground and hoping for the best. There’s an art and a science to how and when mulching should take place.

“A 3- to 4-inch layer of a mulch such as wood chips is highly recommended once the ground freezes. It acts as an insulation for the roots,” says Alsup-Egbers. “Don’t mulch until the ground is cold, otherwise, it will trick the plant into thinking temperatures are cooler above ground. Don’t put the mulch right next to the stems because mice or other critters may overwinter there and nibble on the bark for sustenance.”

The Secret Sauce to Fall Planting Success

The other secret to success with fall plantings is patience. A fall-planted perennial doesn’t look like much as time marches on, and it can be tempting to lose hope entirely that it’s going to actually do what it’s supposed to do come spring. As long as you’ve put your plants in an appropriate place, kept them just moist enough, and mulched them appropriately, you’re all but guaranteed a gorgeous plant — eventually.

“Be patient for your plants to grow the next year,” says Alsup-Egbers. “There’s a saying that for trees and shrubs, they sleep, creep, then leap. Sleep first year, so not a lot of growth. Creep the second year, so you start seeing a little more growth. Then leap to grow more strongly the third year.”

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Should You Plant Perennials This Fall? originally appeared on usnews.com

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