Perennials: Ongoing Maintenance

Perennials

Class 1: Some Perennials Basics
Class 2: Garden Design
Class 3: Putting Pencil to Paper
Class 4: Soil Preparation and Planting
Class 5: Maintaining your Perennial Gardens
Class 6: Troubleshooting

Once established, perennial beds benefit from routine maintenance. Let’s go through the seasons and look at what gets done and when.

Spring
For gardeners, nothing is as thrilling as seeing the perennials they so carefully nurtured last year poke their heads up after a winter buried in snow. Some perennials show up in late winter or very early spring, while others take their time. Don’t despair if you don’t see all your perennials all at once! Some may not sprout for weeks after the first ones appear.

Spring clean-up. Don’t do anything drastic in early spring. The soil may be wet, and the plants are just waking from their dormancy. Some gardeners rake out their perennial beds on the first warm day of spring, but those leaves and other debris may protect delicate sprouts from late cold spells. Once the weather has warmed up reliably, go ahead and gently clean up the beds.

Edging. No matter how thoroughly you weeded and mulched last season, grass will begin to sprawl into the edges of perennial beds. Spring is a good time to edge beds. You can do this by installing commercial edging, or by simply digging a 4- to 6-inch deep trench around the bed.

Fertilizing. A spring application of a one-inch layer of compost provides some of the major nutrients and often all the micronutrients your plants will need for that growing season. If your soil is nutrient-poor, then additional feedings can be helpful. Since you can’t incorporate fertilizers into the soil of perennial beds like you can in annual gardens, some gardeners like to use soluble fertilizers and/or foliar sprays to provide extra nutrients. Don’t overdo it, though. Follow label directions carefully, especially when it comes to diluting concentrated fertilizers.

Mulching. Organic mulches like bark mulch and pine straw break down over time. This is one of their benefits, since in doing so they add organic matter to the soil. However, this also means that they need to be renewed periodically. Add a thin top-dressing of fresh mulch each spring, leaving the old mulch in place to decompose.

Pruning. Since herbaceous perennials die back to the ground over the winter, they don’t require any spring pruning. (Many flowering shrubs and other woody plants benefit from spring pruning, especially to remove dead or diseased branches.) Some gardeners like to pull off old foliage that has died back, but this isn’t really necessary unless the plant is particularly prone to disease or insect problems. For example, you can help prevent problems with iris borers by cutting iris flower stalks and foliage at ground level each fall and destroying the prunings. This eliminates overwintering eggs.

Some late-blooming perennials benefit from pinching back or shearing during the spring. Chrysanthemums and asters, in particular, will produce bushier growth and more blossoms if new shoots are pinched back, or the entire plant is sheared back an inch or two, several times during the early part of the growing season. Every time you remove a growing tip, two sprouts appear in its place, so you see how multiple prunings will create many new sprouts, and therefore many new places for leaves and flowers to form. Stop pinching back in early summer, or the plant won’t have time to form flower buds.

Class 5, Page 1 2 3 4 5 6

Garden Maintenance FAQ #2

Each spring I see small seedlings of some of my perennials, such as lupine, foxglove, and coneflower, around the base of the "parent" plant. Should I let these seedlings grow where they are, transplant them, or just pull them out?

Answer

Encourage children to think about the role of flowers in a plant's life cycle. Showy flowers evolved to attract pollinators, so it's interesting to look at flower shapes and try to guess what pollinators they attract. Honeysuckle, for example, has long, tubular flowers that provide nectar to slender-billed hummingbirds. As they gather nectar and move from flower to flower, the hummingbirds inadvertantly transfer pollen among the flowers.

Breeders are continually developing plants to have showier flowers; however, even though the new plants' flowers are larger or more plentiful, they may produce less nectar than the plants from which they were bred.