Late Chrysanthemum Flowering Time
If you’re growing your flowers late and are wondering, ‘When do chrysanthemums bloom?’ you’re likely to find that they flower between mid-October and mid-January. Lates are normally grown in pots so that they can be more easily brought in to flower in a greenhouse, free from frost.
Growing late chrysanthemums
Late-flowering chrysanthemums should be moved to the greenhouse to flower between 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. By the time June comes around, they should be potted into their final pots—a 20cm/8in or 23cm/9in pot with a supportive cane suitable for the variety's final height.
Then, they can be stood outside. If you are unsure whether they are ready to pot on, turn the pot upside down and tap the plant out, making sure to stop it from falling. If the root covers the outside of the soil, then it is ready. If not, put it back in the existing pot and leave it for around another week. At the beginning of June, the top 2.5cm/1in of the stem should be removed—this is called pinching or stopping.
If you want blooms, four side shoots should be retained, and only one bud at the top of each stem should be allowed to develop. 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 begin to show colour around the end of September, move them back into the frost-free greenhouse. Give plenty of ventilation to keep the humidity down and prevent the damping of the petals.