Intensely blue flowers cover this semi-evergreen South African shrub (Plumbago auriculata) for a large part of the year, and it will climb a lattice happily, though it cannot cling to a wall on its own. Frost is its one weakness: keep it above 0°C and the blooming returns each year with the new leaves.
| Name | Plumbago auriculata |
|---|---|
| Former name | Plumbago capensis |
| Family | Plumbaginaceae |
| Type | Shrub |
| Height | 3 to 6 ½ feet (1 to 2 metres) |
| Foliage | Semi-evergreen |
| Soil | Ordinary |
| Exposure | Full sun |
| Flowering | Late spring to mid-autumn |
Caring for this plant, from planting to pruning, are good practices that will help you obtain a beautiful blooming.
Favor planting plumbago in spring in a place with a lot of sun.
When not in this season, simply avoid high temperatures to plant your plumbago.
It is advised to plant your plumbago in good flower plant soil mix. As with most container-grown flowers, drainage is very important. Roots should never sit in water.
Plumbago is not a difficult plant to multiply, but there are a few tips and rules to follow for success.
There are different ways to propagate plumbago. The main techniques include cuttings, seed propagation, and layering. They have varying degrees of success. In the end, cuttings are best because they guarantee 100% similarity to the mother plant.
Plumbago asks for very little, but the little it asks falls at set moments of the year. Here is the whole cycle gathered in one place before the detail that follows.
| Task | When | What to do |
|---|---|---|
| Planting | Early to mid-spring | Full sun, in a mix of soil mix and garden soil, with frequent watering afterwards |
| Potting and repotting | Every two years | Good flower plant soil mix over a layer of clay pebbles, so roots never sit in water |
| Watering | Late spring to early autumn | Regularly but not too much for plants in the ground; far more in hot weather and in pots |
| Feeding | Early spring to late summer | Flower plant or shrub fertiliser every two weeks, stopping as soon as flowering ends |
| Pruning | Late winter to early spring | Optional and light, to stimulate the blooming and preserve the shape |
| Winter rest | Early to late winter | Reduce watering; keep it clear of frost, as it suffers below 0°C |
In tropical climates, where it never cools down, the plant simply flowers on and on.
It isn’t really a requirement to prune.
Annual pruning is eventually possible at the end of winter or at the beginning of spring, proceed lightly in order to stimulate the blooming and preserve the shape.
Plumbago, apart from watering after planting, will need a lot of water when the weather is hot, especially if grown in a pot.
For the best growth and an abundant blooming, add flower plant fertilizer or shrub fertilizer every two weeks in spring and summer.
Stop adding fertilizer as soon as your plumbago has stopped blooming.
You can set it up in your garden if the climate is mild enough. Double-check that this is possible, because plumbago is vulnerable to frost and will suffer if temperatures drop below 32°F (0°C).
Where freezing isn’t too harsh (light frost), plumbago will lose its leaves. They grow back in spring, with the blooming.
Although it generally resists diseases well, plumbago regularly experiences aphid onslaughts.
Aphids leave sticky honeydew on plumbago foliage, and a black sooty mould soon grows on it, so wipe affected leaves with soapy water and rinse them clean.
Plumbago trained flat against a warm wall gets poor air circulation and can develop powdery white patches on the leaves; thinning a few stems restores airflow.
On plants overwintered indoors, check leaf undersides for red spider mites, which multiply fast in dry heated air.
Birds and butterflies love plumbago for different reasons.
Bees are also often attracted to the nectar. Deer, on the other hand, don’t find the plant very appetizing.
Check the shrub for occupied nests before your late-winter trim.
Its deer resistance makes plumbago a sound choice for an unfenced boundary, though young plants are still worth protecting until they thicken up.
The sticky glandular hairs on a plumbago’s tubular calyx, not the corolla, trap tiny insects; this is a normal feature of the plant and needs no treatment or pest control.
One of the more common plumbago varieties is the tight-flowered ‘Monott’ plumbago. It has beautiful round clusters of flowers.
Another beautiful variety that comes in either blue or white is the Plumbago Escapade series. It is especially happy when simply growing in pots and containers.
Red-flowered plumbago is a different species, Plumbago indica, and it is markedly more cold-sensitive than the blue Cape plumbago.
Grow the red one in a pot that can be kept indoors, warm and frost-free, all winter long.
Plumbago auriculata var. alba is the white-flowered form of the usually blue species; like the blue, it benefits from regular removal of spent, browning flowers to keep the display looking clean.
If you want a plumbago-blue that survives real frost, plant Ceratostigma plumbaginoides instead: it is a hardy ground-cover perennial that dies back and resprouts, not a true plumbago.
This small vining tree, native to South Africa, propounds beautiful blooming for a large part of the year.
The intense blue of its flowers is particularly remarkable and appealing.
But it is particularly well-suited to growing in pots, which will make it easy to bring them indoors to a cool spot that is sheltered from the harshest colds over winter.
Lastly, if you wish to train it into a climbing vine, you can attach it to a lattice because it won’t cling to the wall on its own.
In our latitudes, when grown in a pot, a plumbago plant can reach anywhere from 3 to 6 ½ feet (1 to 2 m), whereas it easily rises to 13 to 17 feet (4 to 5 m) in its natural environment.
Plumbago can trigger rashes and dermatitis on skin. For most persons, it’s insignificant but some persons are naturally more sensitive and might need to see a doctor if itching or reddish patches appear.
The name “Plumbago” (pronounced – plum-BAY-go) has its roots in the Latin word “plumbum”, which means lead. In olden times, it was believed to be a medicinal plant used as a cure for lead poisoning.
Today, modern research hasn’t yet been carried out to prove or disprove the claim, so don’t rely on it – consult a physician instead!
Another possibility is linked to the use of lead to make paint colors – color blue, like the flower!
If you place it next to a footpath, be ready to spend your time picking seeds from your clothes! They’re light and covered with small hooks and will stick to your clothing. For that reason, it’s best to place them far from pathways.
