Lithodora

Lithodora Care

Lithospermum Diffusa

Other names: Glandora Diffusa

What is the plant

Glandora diffusa, the purple gromwell, syn. Lithodora diffusa, Lithospermum diffusa, is a species of flowering plant in the family Boraginaceae. It is a mat-forming perennial growing to 15 cm (6 in) tall by 60 cm (24 in) or more wide, with dark green, hairy evergreen leaves and masses of blue or white 5-lobed flowers. It is suitable for cultivation in a rock garden or alpine garden.

If you’ve recognized any mistakes feel free to notify us about it. This would help us to provide only the best-quality information.

Humidity

Normal

Lighting

Full Sun

Hardiness zone

6 - 8

Difficulty

Medium

How to Care for the Plant

Water
Water thoroughly at least once a week to encourage new roots to grow down deeply. One inch of rain per week would suffice and is needed for most perennial plants. Add a light layer of mulch on top to reduce weed germination and hold in moisture and warmth. Organic aged bark or shredded leaves will contribute a natural aesthetic and improve the soil as it breaks down. Always keep the mulch off the stems of plants to prevent rot.
Pruning
There are several things to consider when carefully pruning Lithodora. The plant may become straggly, and the stems or leaves may become damaged by cold winter temperatures. As you would do for any evergreen, wait until early spring to prune it. Remove any blackened leaves that could prevent new growth and possible disease.
Fertilizer
As new growth appears, a light fertilizer may be helpful but it is not necessary. Avoid using granular fertilizers near the plant crown and foliage, as these may cause burn injury. Instead, use a low rate of slow-release fertilizer.

Disease diagnosis

Check your plant’s health

Ease your plant care routine with PlantIn's personalized system.

Sunlight
While Lithodora thrives in full sun, it can also grow in partial shade. Give the plant afternoon shade in hotter climates. Protect from direct, hot sunlight and extreme winds until plants become established.
Soil
Provide moderately rich, well-drained soil, preferably sand, as the plant will not tolerate heavy clay soil. Acidic soil is good, though Lithodora oleifolia "Olive-leaved gromwell" prefers a pH that is alkaline to neutral.
Temperature
Lithodora tends to bloom less or stop blooming in the hot and humid summers of the Deep South of the United States. Cut plants back to refresh them. Reapply mulch in autumn if planting in a cooler region such as USDA Zone 5 or 6.