Caring for perennials with three proven pruning methods

ILLINOIS Expansive Gardening Team

Pruning perennial flowers takes the garden from looking pretty to being well cared for. Deadheading, clipping, and pinching are all pruning techniques that can keep perennials well-cared for and healthy.

Pruning perennials is a complex topic because different plants need different types of pruning. Experience, developed with practice and careful observation of plants, helps to determine when and what type of pruning is required. Fortunately, perennials are tolerant, so experimentation won’t usually cause permanent damage. Long-stemmed plants, shredded leaves, or new growth at the base of the plant are signs that the plant is ready for pruning.

death

Many perennials bloom for three weeks or less. Deadheading is one way to encourage a longer flowering time in some species.

After flowering, the plant puts a lot of energy into making seeds to complete its life cycle. Deadheading or removing blooms after flowering forces the plant to work harder at making new blooms.

Deadheading techniques depend on the species. Because of their different growth habits, some plants require that the next flower head, bud, or leaf be cut off, while others require that the flower stalk be removed.

Common perennials that should be deadheaded until the next side flower, bud, or leaf to encourage a longer flowering time include:

Butterfly weed (Asclepias tuberosa)

Purple carnation (Echinacea purpurea)

Cochineal bee balm (Monarda didyma)

• Garden Phlox (Phlox paniculata)

• Culver root (Veronicastrum virginicum)

Reducing

Thinning is the second pruning option for perennials. Increasing plant vigor, delaying flowering time, and controlling height are some of the reasons for choosing to cut back plants. Cutting back when the foliage looks tattered, and new growth at the base of the plant can freshen up the look. The renewed growth also helps keep the plant healthy.

Removing old, worn leaves with healthy new ones reduces stress and can increase the life expectancy of the plant.

Cutting the plant can delay flowering time or manage plant height. With some plants, cutting back can lead to a second bloom. It is best to cut the entire plant at once. With continuous flowering, a perennial can use all of its energy to flower in one season with none left to make flower buds the following season.

Some species can tolerate being cut down better than others. It is essential to pay close attention to the signs that cutting back will be beneficial. Cutting back more than half of the foliage can put the plant under some stress, so be sure to give the plant some extra attention until it starts new growth.

Perennials that benefit from being cut back early in the summer include:

• Sedum (Hylotelephius spectable)

Cardinal flower (Lobelia cardinalis)

The Golden Stick (Solidagos)

pinching

The third option for pruning perennials is the pinching method. Pinching can cause the plant to produce more but smaller flowers by removing the central flower bud. On the other hand, pinching lateral buds can force the plant to put more energy into one large flower.

Perennials that can be pressed back to benefit the plant include:

• Yarrow (Achillea millefolium)

Chrysanthemum (Chrysanthemum x morifolium)

• Goldenrods (Solidago hybrids)

Another benefit of pinching certain stems is to increase air circulation through the plant. Increased air circulation helps reduce the possibility of disease. Removing diseased or infected stems by pinching helps keep plants healthy.

Gardener’s Corner is a quarterly newsletter from the Illinois Extension team of gardening experts. Each issue highlights best practices that will make your houseplants, landscape, or garden shine in any season. Join the Gardener’s Corner email list for direct access to timely tips!

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