SEPTEMBER
2008

 

 

 

By
B. Rosie Lerner
 
Purdue Extension
Consumer
Horticulturist

 

 

 

 

 

09-18-08

Consider Garden Mums for Fall Color

While many of summer's perennials are winding down for autumn, you can refresh your garden's color with garden mums. Colors ranges from many shades of yellow, orange, red, purple, bronze, pink and white. The flowers themselves come in many different forms, from spider types with long, narrow petals to cushion types that have wider, more compact flowers.

Some mums are bred as outdoor garden plants, but many are bred as florist-potted plants, meant to be enjoyed only once and then discarded. Many of these florist types, and even some of the garden types, are not dependably hardy in our area. Florist mums can be planted in the garden to be enjoyed for that growing season, but should not be expected to make a comeback in subsequent years. When buying for the garden, get plants from a garden center or nursery that carries plants grown for the outdoors.

The best planting time is late spring, but fall planting can be successful with a little extra attention to watering and winter protection. Choose a sunny, well-drained location with good air circulation for optimum growth and disease resistance.      

Mum plants flower in response to both day length and temperature. Most cultivars begin to develop flower buds when days are less than 12 hours long and generally continue to flower for a period of 6-8 weeks. Some cultivars are not as responsive to day length and may begin flower development early in the summer in response to heat. Catalogs usually list cultivars as early, mid-season or late types.

Plants purchased this summer and fall have likely been groomed to have a compact habit that is loaded with flower buds. In order to recreate that effect next year, you'll need to do a little pinching in the spring and early summer to promote branching. Remove about one-half-to-1-inch of stem back, making the pinch just above where a leaf is attached. The first pinching should be done when the plants are about 6 inches tall (about mid-June) to induce lateral branches. As soon as these lateral branches become 6 to 8 inches long (about mid-July), pinch their tips again to induce more branching. Removing that much plant growth may seem drastic, but the results will be compact, well-shaped plants that are loaded with flowers.

Garden mums are generally hardy throughout Indiana, but many plants can be lost following extreme winters; this is especially likely on poorly drained soils. Mulching for winter protection can be helpful, especially for newly established plants. The purpose of the mulch is to keep the soil cold after it has become frozen, eliminating alternate freezing and thawing and the resulting soil heaving. Wait until late November or early December after 2 or 3 episodes of temperatures below 20 F.

 

Writer: B. Rosie Lerner
Editor: Olivia Maddox