The definition of a perennial plant is one that comes back every year. The process of taking care of a perennial plants can be an enjoyable task.

Perennials are like our pets: from time to time, they look to us for some help to be sure they do their best! Fall is the perfect time to take care of your perennials, check and see if any need to be moved to a new location or if it has over grown an area and may need dividing.

How are your perennials doing?

Take a look at your existing perennials and think about how they performed this year. The right plant for the right place is important: are your perennials getting enough light and moisture? For example, a typical indicator that a flowering plant isn’t getting enough light is poor flowering; too much light can show itself with the foliage looking burned.

The right moisture is also important. Perennials such as yarrow, dianthus, coneflowers, lavender, and ornamental grasses prefer drier conditions. Ferns, daylilies, hostas, coral bells, and daisies need consistent moisture. Fall is a good time to divide and move plants to improve their growing conditions.

Deadheading and cutting back

This simple act of removing spent flowers from a plant will encourage the plant to produce more blooms. It also prevents plants from going to seed. In the fall, many perennials such as coneflowers and sedums have interesting seed heads or tops. Leave some of these for winter interest in the garden; seed heads are an excellent food source for the birds.

It’s your choice if you want to cut back your perennials now. Those that reseed are a good candidate to cut back. Cut back any perennials that have diseased foliage like powdery mildew or black spot; some diseases can over-winter in the soil. Cut all the plant down and be sure to remove and destroy all foliage from the area. Perennials that have heavy insect damage or very large leaves such as hostas should also be cut back now. Insects can lay eggs and over-winter in the old foliage of their favorite plants.

Dividing

Dividing perennials helps rejuvenate them and keeps them from spreading too much. The plants will tell you when. Look for signs of overcrowding such as smaller leaves, clumps dying out in the center of the plant, smaller or fewer flowers. Fall is a good time to divide.

Before you start, know whether your perennial’s root system is a spreader, clumper, or has a woody crown. Spreading perennial ground covers spread by modified stems that root where they touch the ground. Just dig up the newly formed “baby” plants and transplant them. Clumping perennials such as daylilies or hostas, have fibrous, spreading roots. Keep these in mind, dig up the whole clump and pull/cut the root ball apart and transplant the divisions.

Perennials such as coral bells have a single woody stem or crown. Dig up the whole plant and shake off the soil. Cut off sections of crown, each with a few leaves, and replant them individually. It’s best to divide on a cool and cloudy day.

Fall is a time for planting

Garden centers may have perennials on sale. Share or exchange perennials divisions with other gardeners. This is also a good time to amend your soil with compost. You don’t have to dig your perennials out; just work the compost into the existing soil around your perennials.

Fall is also a good time for a soil test. Doing this now will allow you to add the necessary amendments to your soil and it will be ready for planting next year. The Cornell Cooperative Extension Oneida County can help you with this task. Visit our website at https://cceoneida.com/home-garden/gardening/soils-climate for more information. Happy fall gardening!

Home and garden questions can be emailed to Cornell Cooperative Extension Oneida County’s homeandgarden@cornell.edu or call 315-736-3394, press 1 and then Ext 333. Leave your question, name and phone number. Questions are answered weekdays, 8am to 4 pm.