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 beautiful splash of vivid color to any garden. Though it spreads aggressively and rapidly, it is not technically considered invasive. Plant seeds after the threat of frost has passed for quick blooms to start in late spring and enjoy them as early as summer and into fall.

Spur Valerian for Soil Erosion

This old-fashioned wildflower is often planted on hills and slopes. Its deep roots help prevent soil erosion.

Spur Valerian Care

• Provide your spur valerian with plenty of sun.
• Amend your soil for slight alkalinity.
• Be careful not to overwater.
• Prune to control any unwanted spread.
• Do not plant in areas of extreme heat and humidity.
  

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 with natural rainfall alone. This plant doesn't tolerate over-watering well. You'll only need to water a mature specimen if there has been a prolonged scorching 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': This variety offers clusters of crimson blooms and is often found in cottage gardens or crevices of stone walls.
• Centranthus ruber 'Roseus': Blooming in pink, it blooms all summer and makes a great companion plant.
• Centranthus ruber 'Albus': A plant offering white flowers on blue-green foliage, this is a popular heirloom flower.

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

Bloom Months

Spur valerian blooms through the summer and into the early fall months.

What Does Spur Valerian Blooms Look and Smell Like?

Spur valerian produces star-shaped flowers in vivid colors. Spur valerian has a strong fragrance and pollinators can't resist this flower as it blooms throughout the summer. Some gardeners find the fragrance unpleasant while others find it sweet.

How to Encourage More Blooms

Make sure soil is well-draining and deadhead regularly through the summer to prolong blooms.

Caring for Spur Valerian After it Blooms

Prune back spur valerian flower stems once it's finished blooming to prevent self-seeding. These seed pods will eventually disperse over the landscape and may spread the plant where it's not wanted.

Deadheading Spur Valerian Flowers

It's necessary to deadhead spur valerian blooms as they fade otherwise, similar to a dandelion, they developed seed heads will scatter in the wind and could spread invasively.

From: thespruce