Late flowering chrysanthemums are grown in pots outside until frost is likely, then are moved into the greenhouse to flower, flowering in November and December.
On arrival they can be treated the same as garden ones, but in early May they should be put into 13cm (5in) pots and in early June they should be potted into their final pots, approx. 23cm (9in) using a cane suitable for the final height of the variety. They can then be stood outside
Four side shoots should be retained with only one bud at the top of each stem being allowed to develop if you want blooms. For sprays you simply let all the buds develop. The plants should be fed every two to three weeks until early September when the buds start to form. When buds start to show colour, about the end of September, move them back into the frost-free greenhouse. Give plenty of ventilation to keep the humidity down and prevent damping of the petals.