Care and Cultivation of Chrysanthemums 2015
We make every effort to ensure that these plants leave us in top class condition and we hope that they have travelled quickly and well. The different collections often have different despatch dates and any other collections you have ordered will be with you as soon as they are ready. Normally this is within a fortnight, except for the few that are sent out in early June to keep the final height down. To enable you to obtain the best results, the following are a few helpful hints that you should do now.
For best results pot into 9 cm. (3½in) pots in a good peat based general-purpose compost or a John Innes No. 2 soil mix.
Each cultivar has different characteristics. Some may be tall and thin others short and thick, but each will give good results if handled correctly.
Water in after potting, but also leave to almost dry out before watering again. Keep out of direct sun for the first few days, until the roots are working. Then they will take as much sun as you can give them.
The young plants will have sufficient food in the compost for 3 to 4 weeks and extra feeding before this stage is not recommended.
Keep the plants in a greenhouse or conservatory with plenty of ventilation. They are better too cold than too warm. If they do go just below freezing one night spray the leaves with cold water before the sun gets on them. This will help them to thaw slowly and they should be all right. A thin yellow line around the edge of the leaf is often a sign that they have had a cold check.
From April onwards they can go out into a cold frame. When the pot is full of root they can be potted on into a 13 cm. (5in) pot, or planted outside from early May onwards.
EARLY FLOWERING (OUTDOOR/GARDEN) CULTIVARS
Early flowering chrysanthemums bloom outdoors in August and September in the open ground and can be planted out in the garden from April. Before planting scatter 1oz per square yard of a good general fertiliser and rake it in. Plant firmly about 2 feet apart. You can plant closer if you want blooms for cutting or further apart if you need to fill a large area. Insert a cane, tie the stem to it and water in. Feed every two to three weeks until August when the buds will be starting to form. If you give too much feed you get a larger but softer plant, which can be more susceptible to disease.
Most cultivars can be stopped about the 1st week May, or, if it is after this date, when they are about 15cm (6in) tall. It is better not to stop them at the same time as planting outside. If they have formed premature buds it is best to cut them back hard, at least half their height. This will encourage new shoots to grow from lower down without buds. Four or five of the resulting side shoots should be retained. For blooms, one bud should be allowed to develop on the top of each side shoot with other buds being removed as they appear. For sprays all buds should be allowed to develop.
LATE FLOWERING (INDOOR/GREENHOUSE) CULTIVARS
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, a 20cm. (8in) or 23cm. (9in) using a cane suitable for the final height of the variety. They can then be stood outside. If you are not sure whether they are ready to pot on, turn the pot upside down and tap the plant out, making sure to stop it 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 another week. About the beginning of June the top inch of the stem should be removed, this is called pinching or stopping.
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.
For cultivars despatched late May and early June pinch the top out about the third week in July. They can then be treated the same as the other greenhouse/garden ones sent earlier.
All the Spartan cultivars are completely hardy, given a good first seasons growth to build up the root system. The newly arrived cuttings should be treated the same as the other garden ones to start with. They can be stopped early May or if they arrive later; when they are about 15cm (6in) tall. From the end of May onwards they can be planted out about 46cm (18in) apart, the taller ones will require staking. After flowering, cut them back to about 16cm (6in) above where the single stem breaks into flowering stems. When they start growing again in the spring the old stems can be cut right down to near ground level. Every few years they can be divided up or new young shoots rooted.
GARDEN BUSH (POT MUMS)
These are dwarf free-flowering cultivars suitable for pots or border planting. Pot first into 9 cm (3½in) pots then when potting on, put one into a 13cm (5in) pot, three in an 18cm (7in) pot or five in a 25cm (10in) pot. Plants can be stopped to encourage breaking. Feeding should be carried out every couple of weeks through the summer to produce the stunning large cushions of flower in the autumn.
GREENHOUSE, DWARF POT BLOOM & HOUSEPLANT SPRAY CULTIVARS
Versatile cultivars which can be grown in a number of pot sizes to suit your needs. Put one into a 9cm (3.5in) pot, three into a 12cm (4.8in) pot, five into a 14cm (5.6in) pot or six to seven into a 23cm (9in) pot. The growing tips should be pinched out approximately fifteen days after planting and again in the third week of July. Plants can be grown outside during the summer months. Feeding should be carried out every couple of weeks. When the buds start to show colour, move the plants into a frost-free greenhouse/conservatory. Give plenty of ventilation to keep the humidity down and prevent damping of the petals. Only one bud should be allowed to develop on the top of each stem. Once in flower move the House Plant Spray types into the house for a bright and colourful display.
For cultivars grown outdoors in the open ground, after flowering has finished cut down to a few inches above where the single stem breaks into flowering stems. Lift with a fork, shake off any loose soil and remove all the old leaves and any old basal shoots. Store in a cold greenhouse, either in pots, boxes or a prepared bed. Use a general soil-less compost and make sure they are not planted too deeply. Water to settle in but keep on the dry side. In spring the main stem can be cut down again to about 6” from the ground and the plants watered.