The plumbago is a tender shrub with pale bluein summer which is ideal for growing up the wall of a sun lounge. A conservatory or a lean-to greenhouse. The best species for these conditions is Plumbago capensis. It is not a true climber but may be treated as one and is excellent for training on canes, on trellis work or a wire ‘umbrella’.
Plumbago can be grown in large pots (6-, 7- or 8-in. size), or tubs, using John Innes No. 3 Potting Compost. Alternatively, it can be planted out in a bed of good loamy. The shoots should then be trained as I have outlined. With pot-grown specimens I find it is best to push four canes in the sides of each pot. Each cane being 4 to 5 ft. long, then as the shoots develop – which they do very vigorously – they can be trained round and round the canes to form a pillar of blue flowers during the summer months.
In the spring, plants growing in large pots or tubs should be topdressed with fresh compost, having first scraped away 2 or 3 in. of the old compost.
This plant can be raised from cuttings of soft young shoots. 3 to 6 in. long, taken in May or June, or made from harder wood taken in August. September or October. These cuttings should be rooted in a propagating frame with a temperature of 16 to 18°C. (60 to 65°F.), and potted up in 3-in. pots using John Innes No. 1 Potting Compost. Pot on into larger pots as the plants increase in size, using No. 2 and No. 3 potting composts as necessary.