Plumbago - Leadwort
(Plumba'go)
DESCRIPTION: These are leaf-losing (deciduous), flowering shrubs that can be grown in a greenhouse in the North and outdoors in the far South. P. capensis, the more popular kind, is from southern Africa. In a greenhouse it needs a winter temperature of 45-50 degrees. It will flourish outdoors in a sunny area in mild climates such as Florida and California. In a greenhouse this plant can reach a height of 8 feet or more. It bears clusters of beautiful pale blue flowers, mostly in the summer, but it more or less continues throughout the autumn months. The long shoots can be trained up onto a trellis or other support. A white flowered variety, P. capensis alba, is also grown. Another kind P. indica (rosea), produces rose-colored blooms in the winter and spring. It needs a higher temperature (55-60 degrees) than P. capensis.
POTTING: They will grow the best in prepared beds of soil on the floor of the greenhouse. A hole, 18 inches deep and 2-3 feet across, should be dug and the soil removed to make room for the prepared compost. A 6-inch layer of stones or broken brick is put in the bottom for drainage and the remaining space is filled with compost consisting of two-thirds fibrous loam and one-third decayed manure, leaf mold or peat moss and sand. Thoroughly combine these ingredients and firm it moderately. Planting should be done in early fall or in the spring. When planting is finished, they should be watered well. Afterwards and until the roots have penetrated the new soil, watering should be done very carefully. The soil should be nearly dry before they are watered and then they should be soaked. They should be pruned in February or March. If the plant is trained on a trellis, then the shoots should be shortened by one-third or by one-half if they are weak. They should be spread out as horizontal as possible to make sure the base of the trellis is covered nicely with shoots. Flowers grow from the new growth. In later years, when the framework of the branches has developed, pruning consists of shortening the side shoots to three or four buds on the base of the past summer's growth. Until the plant has occupied all of its given space, the main branches will also have to be pruned each spring to encourage the growth of new shoots, which will ultimately provide new branches. When these plants are grown in pots or tubs they need similar treatment. The pot or tub should have great drainage by placing a layer of broken brick or crocks in the bottom and the compost described above should be used. When potting is finished, a 1-inch space should be left for watering. The uppermost roots should be covered with an inch of dirt. They should be pruned to within two or three buds of base of the past summer's growth. Old or worn shoots should also be cut out if there are new ones ready to replace them. When growing these plants outside, they need pretty much the same care as they do when grown in a greenhouse. In climates where they're not winter hardy, plants from 5-inch or larger pots can be planted outside in beds to provide flowers during the summer and then stored in a cool greenhouse or sunroom for the winter.
PROPAGATION: Cuttings are used to increase these plants. New shoots are taken and inserted in pots of sandy soil in the spring or early summer. The pots are set in a propagating case for a few weeks, kept moist, and provided with shade from bright sunlight. P. indica can also be increased by root cuttings.
VARIETIES: P. capensis; P. capensis alba; P. indica.
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