How to Grow and Care for Spur Valerian

Spur valerian (Centranthus ruber) is easy to grow, low maintenance, and has bushy stems that produce an abundance of star-shaped flowers that have an impressively long bloom time. It's a hardy perennial that adds a wonderful splash of vivid color to any garden. Though it spreads aggressively and rapidly, it is not considered invasive. Plant seeds after the threat of frost has passed for quick blooms to start in late spring and early summer and last through fall.

Spur Valerian Care

This old-fashioned wildflower is a great choice for cottage gardens as it'll grow in the cracks of chalky walls and pavers. The cut flowers also look great in a bouquet. The young, fresh, but bitter leaves and the plant's roots also have culinary uses in soups and salads.

Providing your spur valerian gets plenty of sun, you won't have to worry about any complicated or high-maintenance growing requirements. This hardy plant is tolerant of poor, infertile soils, and dry conditions. It's also easy to grow from seeds, root divisions, and cuttings.

Virtually free from pests and disease, spur valerian has a strong fragrance and pollinators can't resist this flower that blooms throughout the summer. Some gardeners find the fragrance unpleasant while others find it sweet. Its deep roots make the plant work well on slopes to help prevent soil erosion.

Light

Spur valerian does best in a full-sun position. It can tolerate partial shade too, but it may not produce quite as impressive a bloom through the summer. The plant may flop over if it's too shaded.

Soil

If you're looking for a plant that will thrive despite poor soil conditions, spur valerian would be a good choice. It copes with dry, infertile soils incredibly well and will flourish in a compact form in areas where many other plants die off.

It does prefer a slightly alkaline soil type. Limestone can be added to create better growth conditions if your soil is more on the acidic side. If the soil you're planting in is a richer variety, you may find that the tall spur valerian will benefit from staking.

Water

A drought-tolerant plant, spur valerian doesn't need a lot of water. Young seedlings will need light watering, but established plants can cope fine with natural rainfall alone. This plant doesn't tolerate over-watering well. The only time you'll need to water a mature specimen is if there has been a prolonged very hot spell and the soil is excessively dry. It is even used in xeriscape gardens with restricted water.

Temperature and Humidity

Spur valerian does not like overly hot and humid summers which is why it won't grow in tropical conditions.

Fertilizer

As you would expect with a plant that copes well in infertile soils, you won't need to fertilize your spur valerian.

Types of Spur Valerian

Centranthus ruber's varieties come in a few other compatible colors:

• Centranthus ruber 'Coccineus' offers clusters of crimson blooms.
• Centranthus ruber 'Roseus' blooms in pink.
• Centranthus ruber 'Albus' offers white flowers on blue-green foliage.

Pruning

Spur valerian dies to the ground in the winter and bounces back with the appearance of daughter plants around each base in the spring. It self-seeds readily, and cutting it back drastically after the bloom period can help to control any unwanted spread. It also means the bloom will be more abundant the following year. Spur valerian often blooms from early summer to September, so don't be tempted to cut back the flowers too early.

Propagating Spur Valerian

Basal cuttings can be taken in the spring or early summer, or you can divide the roots in spring or fall to produce new plants. Division every few years is recommended as this prevents the central section of clumps from dying off, and it stops the root system from becoming overcrowded. Spur valerian can be propagated through several methods. Here’s how:

1. Dig up a clump in spring or fall.
2. Look for natural divisions in the root and separate them with your hands or garden shears. Each division should have its own set of roots.
3. Plant each 12-24 inches apart and water.

How to Grow Spur Valerian From Seed

Growing spur valerian from seed produces good results. If you plan to sow during the winter, pick a sheltered spot, keep the soil slightly moist, and use a tray that can be covered to protect the seeds from any hard frost.

The seedlings can be transplanted into the ground when the temperatures rise, usually around May. Spur valerian seeds germinate rapidly when temperatures climb above 68 degrees Fahrenheit.

Sowing directly into the ground in spring is also possible. As the first leaves appear, it's a good idea to thin them out, selecting the most vigorous seedlings to keep. Make sure you water the seedlings regularly, but only enough to keep the soil mildly moist. Too much watering makes the plants look weedy.

Overwintering

These plants are quite hardy and will survive cold weather. They die back in the winter and grow from the ground up in the spring.

Common Pests and Plant Diseases

Spur Valerian is relatively a trouble-free plant and isn't susceptible to significant pest or disease problems.

How to Get Spur Valerian to Bloom

In order to produce the most impressive bloom, ensure your plant gets full sun. Spur valerian produces star-shaped flowers in vivid colors. Blooms start in late spring and early summer and last through the fall. Make sure soil is well-draining and deadhead regularly through the summer to prolong blooms.