It will be found most convenient to give a liquid feed when watering during dry spells and to scatter a dry feed on the surface at other times to be washed into the soil by rain. There are many well-balanced proprietary fertilisers, all excellent products if used according to the manufacturer's directions. As a guide, it is better to use a fertiliser with a higher nitrogen content during dry periods while one with a higher potash content will help ripen the plants in wet, dull weather. In between, during changeable weather, use an evenly balanced fertiliser. Feed at intervals of 10 to 14 days from the latter part of June until the buds begin to show colour. While exhibitors continue to feed beyond this point to obtain super-sized blooms there is a risk that this will cause damping of the florets. In any case, this extra size is not usually required. PESTS The following are the most common troubles you are likely to come against: Leaf Miner One of the most common pests of chrysanthemums, the leaf miner's presence is made evident by the white wavy lines on the foliage as the grub of the fly tunnels its way along the leaf. Once established in the leaf it is difficult to eradicate so spraying regularly with an insecticide containing pirimiphos-methyl, HCH (formerly BHC) or malathion when this fly is active-usually during the months of May and June-is the ideal control. Aphids Aphids, including greenfly and blackfly, are too well-known to require additional identification. Control with the sprays suggested for leaf miner, with the addition of pirimicarb.season. Cuttings rooted in this way will obviously provide plants which bloom later, but this should not matter for garden decoration. Cultivation of greenhouse cultivars By growing greenhouse cultivars, the period during which mature blooms are available is greatly extended, but there are some fundamental differences in cultivation compared with outdoor flowering types. Cuttings are generally taken about a month earlier (in January) and while the pots in which the plants are growing are standing outdoors during the summer months, feeding is carried out once every seven to 14 days from approximately one month after the final potting until the buds begin to show colour. Most late cultivars are given two stoppings, the first in late April and the second at the end of June. The buds are then produced during late August and September. Late sprays are grown three plants to a 9in(23cm) pot and if the cuttings are not taken until mid-June, the resulting plants can be allowed to break naturally or they can be stopped in late July or early August. If three or four breaks are then retained on each plant, a dozen nice stems should be available in November from each pot. Chrysanthemum Classification and Cultivars As such a large number of cultivars are registered each year, any list of recommendations would soon be out of date. It is, therefore, more useful to comment on how to choose the cultivars you wish to grow.