Plumbago

( plum - BAY - goh )

At-A-Glance Information

This genus of evergreen and semi-evergreen shrubs needs full sun to light shade and little to regular water for best performance. Plumbago plants are commonly called Leadwort. The flowers will attract butterflies to your garden. These plants have a sprawling habit, and bloom over a long season. Flowers can be blue or white, and appear in clusters at branch tips.

Plumbago Species and Varietals

The genus Plumbago includes between 10 and 20 species and is a member of the plant family Plumbaginaceae. The best growing zones for Plumbago vary depending on the species. For more information, see the descriptions below. To find your zone, click here: Zone Map.

​Plumbago auriculata (Plumbago capensis) (Cape Plumbago, Sky Flower, Cape Leadwort)
This species of Plumbago can be evergreen or semi-evergreen, depending on the climate. They do well in zones 8, 9, 12-24, H1 and H2, and are native to South Africa. Creates a mounding shrub 6 feet tall and 8-10 feet wide. If given adequate support, this species can reach 12 feet or more as a vine. Flower color varies from white to blue. Not fussy about soil but needs good drainage to perform well. Use as a cover for banks, fences, or walls or as a background or filler plant in the landscape. Choice varieties include 'Royal Cape', 'Imperial Bliue' or Plumbago auriculata alba. 
Plumbago scandens
This evergreen species grows well in zones 12, 13, 21-24, H1 and H2 and is native to Florida through Arizona, down through Central America. New leaves are a deep red, and mature to a medium green. All foliage turns red in late fall and winter. Flowers bloom year-round with a short break during the warmest parts of the summertime. Blooms are typically white, though they can be blue. Hard prune to control size and encourage colorful new foliage. Good in most soils; can suffer from powdery mildew in summer. Great as a large-scale groundcover. Variety 'Summer Snow' has flowers that are pure white.

Caring for and pruning plumbago shrubs

Plumbago shrubs thrive in full sun to partial shade; the more sun they get the better they will flower. Well-draining soil is of utmost importance for these shrubs. Amending soil with organic matter such as compost is a great idea before planting. Apply mulch around the base after planting. These shrubs prefer regular waterings that keep the soil consistently moist, but not soggy. Provide established plants with deep waterings that will encourage the root system to reach deeper into the soil. Reduce waterings in fall and wintertime when the plant is in its dormant stage. Plumbago should be pruned back hard in late winter to control growth and keep a compact, bushy look. At this time, also remove any dead, damaged or diseased branches. Fertilize with a balanced, slow-release fertilizer in springtime to promote healthy growth and flowering for the year. In cooler climates, provide winter protection to avoid frost damage. These shrubs can also be grown in containers, and can be moved indoors or to more covered areas during the cooler months of the year.

Propagation

Plumbago can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your shrub, follow the instructions below:

Propagating Plumbago by Cutting
  1. Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand.
  2. In spring or early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
  3. Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots. 
  4. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new shrub.

Propagating Plumbago by Seed
  1. Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
  2. Harvest your seeds. The seed pods are pretty easy to spot, left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
  3. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-10 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
  4. Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.
Plumbago seed heads are left behind after flowers fade.
Plumbago seeds.

Problems and Pests

Plumbago shrubs are susceptible to the following issues:
  • Aphids
  • Mealybugs
  • Spider Mites
  • Fungal Diseases
Note that on some Plumbago species, there is a material on the undersides of leaves that looks very similar to powdery mildew. This is actually just a chalky substance secreted by the leaves, and is no cause for concern. For more information on the issues and diseases that are common in Plumbago shrubs, consult the following links:
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Gallery

Plumbago shrubs are great understory shrubs.
Passers-by will marvel at the profuse blooms of these shrubs.
Plumbago can be grown as a formal shrub.

Videos

How to successfully prune a Plumbago shrub.
All about using Plumbago shrubs in your landscape.
How to grow and care for Plumbago plants.
All about Cape Plumbago.

Resources

Plumbago Care: Where and How to Grow a Plumbago Plant
Wikipedia: Plumbago ariculata​
Wikipedia: Plumbago
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Page 519, Plumbago
If you have any questions, comments, concerns, or photos you’d like to add to the gallery, please let me know by sending me a message using the button below!
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