As the last of the late summer blooms start to wane, the true gardener starts thinking of the next growing season and cleaning up beds. Like many perennials, coreopsis has gone to seed and has stopped blooming by mid-September. The urge may be to start pulling and cutting everything, but, like many others, coreopsis will winter better if left alone to die off on its own.
This bushy 18-inch plant commonly known as tickweed is hardy from zones 4 through 9 as a perennial. Coreopsis, with its daisy-like flowers in shades of yellow to pink, will grow fuller and brighter with each passing year with just a few fall prep steps. Coreopsis often is used for naturalized areas or country gardens and are prized for their ease in growing and massive amounts of blooms.
Preparing Your Coreopsis for Winter
Clean debris from around coreopsis base. Dead leaves can harbor pests such as slugs and snails, which consider coreopsis a delicacy. Pull annuals and any weeds.
Leave the coreopsis plant alone. Cutting back in the fall can kill off your plant. Coreopsis foliage will turn a cinnamon color, giving your winter garden an interesting spark. Some varieties of coreopsis should be divided in the fall every few years for best growth. Check with your local gardening center to see if your plants are that variety.
Layer the garden soil with a rich compost or manure. If using fresh manure, be sure to keep it away from the base of the plants as the high nitrogen level of non-composted manure can burn and kill the plants. Laying compost or manure in the fall will give it the winter to break down. Mulch if you'd like.
Cut back coreopsis in the spring after the threat of frost, for best results.