Growing Chrysanthemums – Summer Care of Chrysanthemum Flowers
Many amateur gardeners think that stoppingis a complex business which they will never be able to grasp. In actual fact, it is simplicity itself once the basic facts are understood. The reason for this operation is to manipulate the time of flowering, e.g. to encourage the shoots of a plant to develop earlier than they would naturally, and therefore to produce their earlier. This is vital if you are exhibiting your blooms, as they must be ready by September for the early-flowering chrysanthemum shows and also before the bad weather sets in. Stopping also encourages the production of a greater number of flowers.
Stopping simply involves pinching out the growing tip of a young plant, before it naturally forms what is known as a ‘break bud’. By doing this new growths will form in the first leaf axils below the top of the stem and will develop into sturdy. Each of which will produce a ‘first crown bud’ at its tip. Usually this one stopping is sufficient for most outdoor chrysanthemums, but some varieties may need a second stopping, so the tips of these lateral growths are pinched out. This will encourage further shoots to develop from the upper leaf axils and in turn form flower buds at their tips. These are known as ‘second crown buds’ and there will be a greater number of these than of the first crown buds. It is not often necessary to encourage further laterals, but if these did develop they would produce the ‘terminal buds’.
If no stopping is carried out, the plant will make these ‘breaks’ or shoots naturally, but as I have mentioned they will come into flower very much later.
It is mainly the large-flowered types, such as the Decoratives, which need to be stopped, and I think that one stopping in the early stages of growth is sufficient for normal garden use, to produce blooms from the first crown buds. Most of the small-flowered types, such as Koreans or Pompons, flower much better if left to grow naturally.
The time to carry out stopping is one of the most debatable aspects Of chrysanthemum growing. There are various factors on which this depends the part of the country in which they are being grown, the variety and the weather. Most nursery catalogues give the dates of stopping each variety (this is known as a stopping ‘key’) and whether the particular variety needs one or two stoppings. I am sure that experience is the only way to learn the best times for stopping your own particular varieties, as much depends on your locality. I would advise you to keep records of the stopping dates of each variety that you grow as this will be invaluable information for calculating accurately the times of flowering in successive years.
As a rough guide, the first stopping can be in the first and second weeks of May, and most of it should be completed by the third or fourth week in May.
Thinning Surplus Growths
With many of the modern varieties there is not much thinning to be done, because when they are stopped they will not produce more than about five good shoots. If they produce more shoots than this then some thinning can be done if desired, cutting the surplus shoots out at their bases. Always remove the weaker ones.
For ordinary garden purposes I would allow as many as six or eight flowers on each plant of the decorative types one to each shoot but when they are being grown for exhibition then they must be restricted to two, three or four flowers to each plant.
This must be carried out regularly as the plants grow; one tie when they are planted out and further ties as new shoots develop after stopping. If these shoots are not tied in they will probably be broken off during high winds. Soft, green garden string is best for this job.
This simply means the removal of all surplus flower buds and is particularly important if growing plants for exhibition, or if large blooms on long stems are required for cutting. As I have already mentioned disbudding is not necessary for Koreans, Pompons, Anemones, Sprays and Singles when they are grown for normal garden display purposes. It is really the large-flowered kinds that respond to this operation, but if you prefer to grow these as sprays, with small flowers, then a lot of disbudding can be dispensed with.
You will notice that the tip of each shoot contains a cluster of flower buds, with one in the centre known as the crown bud. It is this centre bud which must be retained all the surrounding ones should be rubbed out. By doing this all the energy of the plant will be diverted to these crown buds so producing good, large blooms. After disbudding, each main shoot should bear one bud only.
If sprays of small flowers are wanted, then rub out the crown bud and leave all the surrounding buds to develop. These will flower a little later than if the crown bud only is left.
Disbudding should be done as soon as the buds are large enough to snap out between the finger and thumb, without causing damage to the stem and the remaining buds. The time for doing this job is roughly towards the end of July. About this time of the year the main stems will be developing numerous side shoots which must be removed in order to divert the plant’s energy into producing good blooms and long stems. These shoots will appear from the base of the stems right up to the top and they should all be rubbed out as they appear in the axils of the leaves, otherwise the flower buds will be starved. I leave about three shoots at the base of the large-flowered types as these will produce a further crop of flowers in October and November, after the first flush of blooms.
I always start feeding my chrysanthemums about late June or early July with a balanced all-purpose fertiliser, preferably one with a fairly high potash content. This will ensure a hard plant with firm-petalled blooms which will stand up to bad weather. It is best to water the plants first if theis dry and then apply a diluted liquid feed, or a soluble fertiliser dissolved in water. I think that even the Koreans, Sprays and Pompons benefit from feeding at this time of the year. Usually one application is enough for these, which can be given in late July. For the large-flowered types a fortnightly feed can be given up to the middle of August, but after this time I do not consider feeding is necessary.
Protecting the Flowers
Bloom for exhibition and for cutting need protecting from the rain, as this makes them spotted and unsightly. In order to avoid a lot of unnecessary work I would aim at growing the older varieties which have harder petals and so withstand the weather much better than a lot of the newer ones which seem to have soft petals.
The simplest way of protecting is by placing greaseproof-paper bags not brown ones over the blooms before the colour of the petals begins to show. You must use bags that admit the light, otherwise up to 50 per cent. Of the colour will be lost. Special greaseproof-paper bags are obtain-able, with a Cellophane window in them these are the ones I would recommend. The bags are left on until the flowers are ready for cutting. Before covering the blooms I like to dust the in-sides of the bags with a little DDT or BHC powder as this prevents earwigs and other insects such as aphids from getting into them and damaging the blooms.
Some growers protect their blooms by building a timber framework around the plants, and covering this with polythene sheeting or Dutch lights. In this case it is only necessary to cover the top of the structure, leaving the sides open.
This job is best done during early morning or late evening when the flowers are fresh. If they are cut during hot weather they will not take up water when placed in vases, and they will just go limp and flop over. Some varieties are more susceptible to this than others. The blooms should be cut with at least to 2 ft. of stem. If you have disbudded correctly then this length of stem will be easily obtainable. After cutting, all the leaves, apart from three or four near the bloom, should be stripped off. The stems are then crushed at their bases, inserted in deep water, and put in a cool, dark place for about 12 hours. This will help to reduce wilting of the flowers. After this time they can be arranged in vases and put on display.
Such types as Koreans, Sprays, Pompons and so on will naturally have shorter stems. As a rule there is very little trouble with flagging and the blooms last well indoors. The large-flowered kinds will last up to three weeks when they are brought into the house.