Ideas & Inspiration
How to Troubleshoot and Care for Perennials in Your Garden
A garden filled with perennials will delight year after year, as plants like hosta and coneflowers grow and thrive. Unlike annual flowers that bloom for a single season, perennials will give you all they’ve got one year, go dormant in winter and will return the following spring, ready to put on a show all over again.
Perennials can be low-maintenance, but that doesn’t mean no maintenance. Sometimes, despite your best efforts, pests and diseases will attack the plants, and plants will fail to thrive in their location. With a few tips, you can learn to treat, and possibly prevent, problems before they begin.
The first step is to know the plants that you grow and be sure they’re perennial in your hardiness zone. Sometimes, plants that are technically perennials in warm climates are treated as annuals in colder climates. After all, the most popular annuals, like impatiens, petunias and begonias, are native to tropical areas.
When shopping in the Garden Center, let plant tags be your guide. Learn more about the differences between annuals and perennials.
Planting hosta in full sun is almost always a mistake. Unlike annuals that, for the most part, love and demand lots of sun, perennials tend to like either sunny or shady locations. Popular perennials grown throughout the country include sun-loving coneflowers, daylilies, daisies, Black-eyed Susans and coreopsis. The most popular perennial for shade, of course, is hosta, but there are more low-light favorites including astilbe, heuchera (coral bells), hellebores (Lenten rose) and Lily of the Valley.
Keep in mind soil type when growing perennials. For example, hostas like moist shade, and heucheras tend to like dry shade. And all plants like soil amended with organic compost.
Throughout their life, perennials need sufficient water, light and fertilizer to grow and thrive. Unlike annuals that get tossed in the compost pile at the end of the season, perennials continue to grow in place. That’s why every two or three years, you’ll need to divide them; late winter is the best time to do that.
Dividing perennials is necessary to avoid overcrowding and to keep your plants as healthy and lush as possible. Plus, you get bonus plants for your own garden or to share with fellow gardeners. You can tell when a plant needs division if it develops a dead core in the center of its crown. Also, if the foliage is fairly lush but the plant is producing steadily fewer flowers each year, it may need dividing. Learn more about dividing perennials.
You can divide perennials in late winter and early spring as long as the soil is workable. Make it easy on yourself and garden on a day after rainfall.
Tip: Slicing through tough stems and roots requires heavy duty tools. A hori-hori knife or all-purpose tool like Ames Planter’s Pal 7-in-1 garden knife can get the job done. Some nursery pros also use a sturdy, inexpensive serrated bread knife to divide perennials.
It’s important to understand that plants will sustain some damage in their environments. Insects will nibble on foliage, flower buds will turn mushy in heavy rains, late winter storms will freeze new growth. Just like our human bodies get bumped, bruised and bit as we maneuver through our environments, so do plants.
We keep our immune systems strong to fight off infections and to heal quickly. The same is true in the garden: give plants what they need for good health, like enough sunlight, water and nutrition, protect them from opportunists like deer and squirrels and learn to tolerate minor imperfections. Most problems, like Japanese beetles in summer, come in for a week or two, then move on.
The Weed, Plant and Pest Problem Solver Tool is helpful for identifying pests and diseases. Learn to identify common pests, like aphids, slugs and whiteflies, and the damage they cause, such as aphids’ cottony webs and slugs’ sticky trails.
Some plants are more prone to diseases, like peonies and botrytis blight. This disease occurs in damp rainy seasons and will destroy peonies from the ground up. Control botrytis blight with a fungicide. Preventive measures include choosing a sunnier location and amending the soil to improve drainage.
In many cases, the solution to the problem is a control, but also in preventive measures such as site improvement, routine care like fertilizing and pruning and amending the soil.
Perennials can sustain damage from pests like deer, squirrels, rabbits, voles and mice. You’ll notice this with plants like hosta being chewed down to nubs. There’s plenty of controls for pest damage, organic and non-organic, but the most helpful advice is to choose plants that deer don’t like. Here’s help for planting a deer-resistant garden.
You can nurse injured plants back to health by trimming off damage, refreshing the mulch and tending with a top dressing of compost. Perennials are by nature resilient plants, and if they have strong roots, they will come back again.
Whether you need the right planters, seeds or potting soil, The Home Depot delivers online orders when and where you need them.