The Busy Lizzies. Impatiens holstii and I. sultanii and their offspring, with gayand glossy looking stems are popular plants for the greenhouse as well as for the home. The flowers appear throughout the summer, and into autumn and winter when conditions are to their liking. Good choices include the varieties Scarlet Baby and Orange Baby, and splendid F, hybrids with large flowers are available, like the 9-in. Tall red-and-white striped General Guisan. A less usual plant is I. petersiana, which has scarlet flowers and dark red stems and leaves.
Impatiens can be grown quite successfully in soilless compost but I prefer to use John Innes No. 1 or No. 2 Potting Compost which I find gives harder plants which flower more freely. I prefer not to use pots larger than 5 in. in diameter. If the plants become pot bound they will flower better than ever, but it will be necessary in such circumstances to feed once a week in spring, summer and autumn with a liquid or soluble fertiliser. They should be placed in a sunny position. Repotting should be done in the spring.
Copious supplies of water are needed from March to September but winter watering must be done with considerable care or rotting may result. Keep the temperature at 7 to I3°C. (45 to 55°F.) from October to February and 13 to 18°C. (55 to 65°F.) from March to September.
Seed is by far the best means of increase. Sowings can be made from late February to May for summer flowering, or in June and July for autumn and winter flowers. The seed should be sown in seed compost and germinated in a temperature of 16°C. (60°F.).
Cuttings of young sideshoots from the base of the plant inserted in sandy compost in a temperature of 18°C. (65°F.) between March and September are another method of increase.