On the whole chrysanthemums are quite hardy plants and easy to grow. Here are some basic guidelines to follow to keep your chrysanthemums healthy and producing good flowers.
Plant chrysanthemums in a sheltered but sunny space. Young plants propagated indoors can be hardened off in a cold frame during April and planted out in May once the risk of late frosts have passed. When planting out leave about 18 inches between plants and dig in a good quality multi purpose garden fertiliser.
Professional Fertilising Tip
For the best lush green foliage and flowers apply a high nitrogen fertiliser each week during the growing season until the first flower buds appear. Once the buds have formed switch to a weekly does of high potassium fertiliser.
Chrysanthemums are often sold as either “spray” varieties or “disbud” varieties. Sprays will produce multiple flower heads branching off from one stem whereas disbuds are meant to produce one large flower head per stem. Sprays are a popular for use as cut flowers and disbuds are often exhibited in shows.
Pinching out the tops in late May will encourage branching. If you are growing disbuds then ensure that all branches are removed from central stems so the plant can put all of its energy into the central blooms.
In mild areas with well drained soil most chrysanthemums will survive outdoors as long as the temperature doesn’t drop below five degrees. Covering them with a protective layer of mulch also helps overwintering outdoors.
The most fail-safe way to overwinter your chrysanthemums is to cut back the growth to about six inches from the base of the plant. Lift the plants in autumn and shake the soil of from the roots. Some gardeners use a garden disinfectant to clean the root stock, it is also recommended to soak them for five minutes in warm water at 45 degrees Celcius which will help kill off any eelworms. Trim the roots to a length of six inches and thoroughly dry your treated root stocks before placing them on dry compost in seed trays with a sprinkling of compost on top. Store the root stocks in a dry airy space – an unheated greenhouse is ideal.
In early spring start to water the roots to encourage new growth. Propagation can be performed by taking cuttings from soft new growth.
Like all plants and trees in your garden chrysanthemums are not immune to pests and disease. In my next post I will write about some of the more common pests and diseases which affect chrysanthemums and how to best deal with them.