Growing Chrysanthemums – Care of Outdoor Chrysanthemum Plants
Outdoor or early-flowering chrysanthemum plants must be planted in an open, sunny part of the garden if they are to give off their best. If the area is shaded for part of the day this will not matter very much, but the plants should not be in a position which receives only about one hour of sun each day, such as in a north-facing border. Under these conditions hardly anywill be produced, and the plants will look drawn and miserable.
The Soil and its Preparation
When it comes to soils, the early-flowering chrysanthemum is fairly tolerant. It will grow in a wide range of different types but, as with the, the better and richer the the better will be the growth and flowers. It is advisable to avoid giving the plants too much nitrogen, as soft, leafy growth will result. The flowers will have soft petals which will bruise easily and will not stand up to wet weather. So, avoid any ground which may have had a dressing of a nitrogenous fertiliser.
As with dahlias the ground should be prepared well before planting time. If the soil is heavy it needs to be dug during the autumn to allow the frost to break it down thoroughly, and if it is a light soil then digging can be carried out just after Christmas. I do not think it is necessary to double dig; just dig to the depth of a spade and at the same time incorporate well-rotted manure,, spent hops or other organic matter to improve the soil structure.
Chrysanthemums like a certain amount of lime in the soil, so I think it is a good idea to carry out a soil test to see whether liming will be necessary. If you obtain a reading of under pH 6.5, then liming will be necessary. The ideal pH should be between 6.5 and 7. Liming is best done as soon after the digging as possible, using hydrated lime which is easily obtainable.
Some gardeners like to give the ground a dressing of bonemeal soon after digging, as this gives the young plants a good start. I would not recommend hoof and horn because this is high in nitrogen and will therefore cause sappy growth. I usually give the dug ground a dressing of basic slag during the autumn or winter, as it is about the cheapest form of phosphate and contains lime also. It helps to improve the soil structure as well.
The time of planting depends to a great extent on the part of the country in which you live. In the southern counties or the West Country early-floweringcan possibly be planted from late March to early April; in the Midlands not until after mid-April, or preferably the last week in April or the first week in May. In the northern counties, I would not suggest planting before the first week in May, and in really exposed areas it may have to be the second or third week in May to be on the safe side. There are no really hard and fast rules; we have to be guided by the weather.
Before planting your chrysanthemum plants, a dressing of an all-purpose fertiliser should be raked into the soil, at 2 to 3oz. per square yard. The soil should then be made really firm.
It is best to plant with a trowel, and to insert a bamboo cane for each plant just before planting. The young plants should be placed close to the canes and the stems tied to them after planting to prevent them from being broken off. Do not plant too deeply, but firm the plants in really well. Very often, as soon as the outdoor chrysanthemums are planted out, birds will come along and start strip-ping the leaves and buds off and this will set the plants back. I would suggest that you spray the plants with a bird repellent, renewing it after rain.
Now to distances for planting. If I am growing chrysanthemums specially for cutting then I plant them 18 in. apart in rows 2-½ ft. apart. These distances are also ideal for exhibition plants; if they are being planted in groups in a border then 18 in. each way is enough to form a good group. I usually put three to five plants in each group. Spray varieties should not be placed less than 18in. Apart, and Koreans and Pompons would probably be happier at 2 ft. all round, as they are very bushy.
Staking Chrysanthemum Plants
It is mainly the large-flowered varieties – or Decoratives – which need supporting, as they grow taller and carry more weight than the others. As I have already mentioned, I insert one cane before planting. Then, as the plants make further growth, I insert another four canes around each one, about 1 ft. from the stem, tilting them slightly away from the plant. I then loop soft twine around these, so holding the stems inside the canes. It is not usually necessary to give further canes to Sprays, Koreans, Pompons and so on, although if it appears to be necessary then by all means do s0.