How to grow Veronicastrum

As part of the Plaintain family, Veronicastrum is a tall, striking and elegant flower with plenty of foliage interest and vibrant colours. The most commonly cultivated species is Veronicastrum virginicum, which is native to North America.

Also known as Culver’s Root, this herbaceous perennial is an easy-going plant to grow and ideal for flower beds and the backs of borders. Veronicastrum’s tall leafy green stems carry dense clusters of small flowers. Veronicastrum cultivars are found in white, pink, purple and blue to add a pop of colour to your garden, while their flowers attract pollinators such as bees and butterflies.

Naturally pest-resistant, Veronicastrum grows to heights of 120cm and around 40cm in spread and takes 2-5 years to fully mature. Furthermore, continual deadheading will encourage further blooms throughout the seasons. A true sun-lover, Veronicastrum thrives in brighter areas of the garden and enjoys well-draining soil.

Ready to add some elegant structure to your garden bed or border? Discover everything there is to know about Veronicastrum below...

Key Information

Soil pH

not fussy

Position

full sun and part shade

Hardiness

hardiness 4 and 7

Where & when to plant Veronicastrum

When planting Veronicastrum, find a position with plenty of sunlight. Full to partial sun is ideal, as Veronicastrum will struggle in shady conditions.

How to plant Veronicastrum

The best way to ensure success is to purchase young plants in pots – this saves you time and investment in the germination and initial growth process

When your seedlings arrive, they are ready to be planted out in milder areas or you can grow them on in a cold frame or greenhouse until the weather warms a little to increase their viability.

Check the pots to see how established the root growth is and repot if required. Alternatively, dig a hole slightly larger than the pot and place the plant in the chosen site along with some grit or gravel to aid drainage where appropriate. Back fill the planting site and water in your plant to aid establishment

Ensure that plants are kept moist, not waterlogged, whilst establishing after which they require minimal care and flowers will return year on year

veronicastrum

What to plant with Veronicastrum

As prairie-style plants, Veronicastrum works well with tall grasses and other perennials. Calamagrostis x acutiflora is a good choice as it grows tall and provides movement and a backdrop for your colourful Veronicastrum. For companion perennials, Rudbeckias are a great pick with a prominently raised disk and vibrant yellow flora. There are also plenty of other Veronicastrum - consider pairing them with other cultivars such as Veronicastrum virginicum Lavendeltrum, Erica or Fascination which provide height, structure and vibrancy.

How to care for Veronicastrum

Pruning & Deadheading

To extend the blooming period, deadhead Veronicastrum frequently. Also cut back to ground level when flowering has finished to encourage a possible, second flowering.

Watering

Veronicastrum enjoys moist, well-draining soil. During the growth phase, water regularly. Once established, water once a week and try not to let the soil dry out.

Cold Protection

Cut back Veronicastrum’s flower stalks in the autumn to prepare for the winter dormancy. Do this before the frost hits and you will see new healthy growth in the following spring. You do not need to mulch or further treat Veronicastrum as it is fully frost-hardy and can tolerate temperatures as low as -20°C.

Pests & Diseases

Veronicastrum is generally a pest-resistant plant. However, you should look out for diseases such as black leaf spots or downy mildew. As with all perennials, root rot can cause issues, so make sure that your soil drains well and that the roots are not left in standing water.

How to propagate Veronicastrum

The best way to propagate Veronicastrum is by division. Do this either in the autumn (before cutting back) or in the early spring after the last frost.

propagate

Select a parent plant to take divisions from which is healthy, disease-free and grows well. Dig up its roots and use clean scissors or a knife to pry away some of the roots. Make sure that each root section has a bud when cutting and do not remove more than ⅓ of the parent plant’s roots. Once you have taken divisions, replant the parent plant as soon as possible

propagate

Fill 7-9cm pots with soil and add one root cutting to each pot. Settle the soil and plant in place by watering in. Put the pots in a sheltered position with plenty of warmth away from direct sunlight and water regularly to encourage healthy growth

propagate

When your plants are ready, they can be planted outdoors in their permanent positions; remember that Veronicastrum needs 4-8 hours of sunlight per day

Common Veronicastrum Questions

Do you cut back Veronicastrum?

Yes, cut back Veronicastrum to around 5cm above ground level in late autumn. It is fully hardy so will come back in the spring.

Will Veronicastrum grow in shade?

While Veronicastrum can grow in shade, the plant is prone to wilting in areas with extended shade. If you do not have somewhere to plant Veronicastrum that is in full sun, plant in an area with at least 4 hours of sunlight a day - this will provide partial sun and partial shade.

Is Veronicastrum hardy?

Veronicastrum is a fully hardy perennial that can cope in temperatures as low as -20°C.