Verbascum cystolithicum Plant Care

Verbascum cystolithicum (Verbascum cystolithicum) belongs to the Scrophulariaceae family within the Verbascum genus. Verbascum cystolithicum is native to Cape Verde.

Verbascum cystolithicum displays a tall spires of flowers growth habit, reaching up to 4 ft tall with a spread of approximately 2 ft. Verbascum cystolithicum produces large, showy spikes of yellow, pink, or purple flowers.

Leaf size: approximately 6 inches.

Water a young or newly planted Verbascum cystolithicum every 7–14 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established shrubs mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Verbascum cystolithicum thrives in full sun to part shade.

Verbascum cystolithicum tolerates temperatures of 50–80°F. Verbascum cystolithicum prefers humidity levels of 40–70%.

Well-draining sandy loam with added compost for nutrients. Good drainage is essential for Verbascum cystolithicum to prevent waterlogging, which leads to root rot and fungal issues.

Feed Verbascum cystolithicum every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established shrubs in good soil often need little extra feeding, so let weak growth or pale foliage guide you.

Stop feeding by late summer so new growth can harden before winter.

The PlantoScan app can remind you when to water and when to fertilize each plant.

Choose a spot with full sun to part shade and well-draining sandy loam with added compost for nutrients. Avoid low spots where water collects after rain.

Verbascum cystolithicum is suited to USDA Zone 12a.

Plant container-grown or balled-and-burlapped shrubs in spring or early autumn, setting the root flare at soil level, and water well after planting.

Verbascum cystolithicum can spread to about 2 ft (0.6 m) and reach about 4 ft (1 m) tall. Space plants about 2 ft (0.6 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.

Planning a row or hedge? Try the plant spacing calculator.

Prune Verbascum cystolithicum while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.

If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the shrub in one year.

Verbascum cystolithicum is frost-tender (hardy to USDA zone 12). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

Verbascum cystolithicum can be propagated through seeds, division of offsets. Similar propagation techniques also apply to bombyciferum mullein plant care, which shares the same genus.

See all plants toxic to cats and plants toxic to dogs.

Verbascum cystolithicum is susceptible to aphids, slugs, snails. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.

Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.

Verbascum cystolithicum grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Verbascum cystolithicum is native to Cape Verde. In cooler regions, grow Verbascum cystolithicum as a houseplant or bring it indoors before the first frost.