One of my favourite bulbs for the greenhouse is the hippeastrum. Incorrectly but frequently called amaryllis. The huge trumpet-shapedin colours which include scarlet, crimson, pink and white. On still, sturdy stems. 2 ft. in length, appear in late winter and spring depending on the temperature they are given.
A single bulb can be grown in a 5- or 6-in. pot and goodis essential. John Innes No. 2 Potting Compost is a suitable growing mixture and the top part of the bulb should be left exposed above the level of the compost. Complete repotting is necessary only every three or four years as the bulbs resent root disturbance and will flower better when pot bound, but each year before starting the bulbs into growth the surface should be scraped away so that a topdressing can be given with fresh potting compost. This is normally done in February but if early flowers are needed and a temperature of 16°C. (60°F.) can be maintained the bulbs can be started into growth in December or January.
Water should be given sparingly until growth is active although the soil must not be allowed to dry out once growth has started.
Hippeastrum bulbs can now be obtained that have been specially treated so that they flower early, the blooms appearing in time for Christmas. They are available for planting in early November. The bulbs are placed in pots in the normal manner and for Christmas flowering they must be placed in a constant temperature of 21°C. (70°F.). At lower temperatures the flowers will not start to show until mid- or late-January. In subsequent years these bulbs will flower at the normal time.
To prevent the flower stems being damaged by accident it is a good idea to support them with thin canes and raffia ties.
After flowering, when the foliage has developed fully, the plants must be looked after well to build up the bulbs for the following year. They should be placed in a warm part of the greenhouse and given feeds each week with a liquid or soluble fertiliser.
Towards the end of the summer, when the foliage begins to turn yellow, watering should gradually be reduced and when the soil is dry the pots can be laid on their sides under the staging. To ripen the bulbs thoroughly the pots can be stood on the staging in full sunlight for a few days before laying them on their sides.
I have practised this method of cultivation successfully for many years but some gardeners feel that the bulbs should not be given a complete rest. The plants are kept cool but are not allowed to dry out entirely, enough water being given to keep the compost just moist. In this way the plants get a partial rest.
Mealy bugs with their white, woolly covering can be troublesome and are usually found in the brown outer covering of the bulb. When dormant, inspect the bulbs carefully by removing the brown skin. Painting with a brush dipped in malathion or white oil emulsion will destroy the insects.