Verbena is known for its long lasting flowers which thrive during the hottest days of summer. A magnet for butterflies and pollinators, verbena is also a great way to add color and structure to your garden. The plants are also pleasingly easy to grow.
In ancient times verbena was popular for its supposed healing properties. Today the plant is also commonly grown for its ornamental value as well as its use as an essential oil.
A delicate looking plant, verbenas are a magnet for pollinators and butterflies. The plant is also an attractive way to bring height or soft structure to a garden.
Different Varieties of Verbena
Verbena plants come in annual and perennial varieties. In areas that are high in humidity perennial varieties perform better.
Most cultivars are full sun plants. However, some varieties happily grow in partial shade.
Whatever your situation, there are a range of verbena plants available. As well as the typical purple verbena plants, cultivars come in a myriad of colors and sizes. The plants also have a range of interesting growth habits.
Trailing varieties, also known as compact or moss varieties reach about 1 ft in height and have a spread of between 2 and 5 ft. Moss verbena originates in South America but is now common across much of the southern United States. One of the most popular cultivars is Imagination. This produces purple flowers that are popular with visiting pollinators. Sissinghurst is known for its prolific flowering habit, producing masses of coral pink flowers from spring until fall.
Verbena rigida varieties are taller, reaching between 1 ft and 18 inches in height. The cultivar Santos produces attractive pink-purple flowers.
The tallest varieties, which include the blue verbena and purpletop vervain, reach between 4 and 5 ft in height. While they may be tall, the spread of these plants rarely exceeds 2 ft.
Purpletop Vervain is also known as verbena on a stick. Reaching up to 5 ft in height, clusters of attractive lavender flowers appear on the end of the plants’ tall, thin stems. A drought tolerant plant, it flowers from late spring until the fall.
Purpletop is often used as a way to plug gaps in flower borders. The airy growth habit of this plant means that it won’t crowd out other plants. A short lived perennial, it readily self-seeds, returning year after year.
Purple varieties are the most common verbena cultivars. However, if you want something a little different, verbeans come in a range of shapes, sizes and colors.
Blue Vervain is one of the most common varieties. Like Purpletop Vervain it has a tall airy growth habit and its blue-purple flowers are a magnet for butterflies. Depending on the conditions the plants can reach 2 to 5 ft in height.
The purple flowering Homestead Purple is another popular cultivar. Its vigorous growth habit makes it a good choice for ground cover. Homestead Purple flowers throughout the growing season. In USDA zones 6 and warmer it is best grown as a short-lived perennial.
Like Homestead Purple, T’exas Rose is a useful ground cover option. Its red-pink flowers have a short lifespan compared to other varieties. Another good, low growing cultivar is Appleblossom. Producing large cotton-candy pink flowers, with a white eye, the plant has a vigorous growth habit.
A good choice for container gardens, Greystone Daphne is a compact variety, producing fragrant, lilac flowers. Flowering from early spring until the first frosts hit, this is one of the hardiest varieties of verbena.
Bonariensis is a Brazilian cultivar. Reaching up to 6 ft in height this plant is perennial in zones 8 and warmer. Like many other varieties, this is a popular butterfly flower. It also self-seeds freely.
Reaching a height of about 60 cm, Lollipop is a reliable, low growing cultivar. It is ideal for containers or smaller gardens. Lollipop looks particularly attractive when placed at the front of mixed flower borders.
How to Grow from Seed
While you can purchase young plants from garden or DIY stores growing from seed is more affordable and often allows you a greater choice of varieties.
Growing from seed is also pleasingly easy. Fill trays with fresh, general purpose soil.
If you are trying to grow in a colder climate, or during the winter, try sowing in seed trays with germinations lids, such as the Soligt Growing Trays with Humidity Domes. These help you to regulate the temperature and humidity levels around the seeds, encouraging quicker germination.
Sprinkle the seeds over the soil. Cover your seeds with a thin layer, about half an inch thick, of fresh soil. Gently spray with water and place in a sheltered light position to germinate. Keep the soil damp.
Following germination, allow the seedlings to grow on. Once they are large enough to handle, thin out the seedlings before transplanting into individual containers.
How to Plant
Begin planting after the last frost has passed. Remember to harden off your plants before planting.
Plant in a full sun position. Ideally the plants will receive 8 to 10 hours of direct light every day. Plants in darker positions may not flower as profusely. They may also be more susceptible to pests and diseases.
An Atree Soil pH meter allows you to monitor how much sunlight your plants are receiving. The meter also measures pH levels and the moisture content of the soil. This helps you to know exactly when to water your plants.
Plant in good, well-draining soil. Verbena also grows in poor soil as long as it is well draining. Perennial varieties won’t return if they are planted in soil that becomes heavy after winter snow and rain.
Working in well composted organic material or leaf mold before planting helps to improve drainage. Alternatively, if your soil is heavy or clay based try planting in raised beds or containers.
After working the soil over with a shovel dig a hole large enough to hold the root system of the plant. If you are unsure how large the hole should be, a good guide is to place the container currently holding the plant in the hole. The container should fit comfortably inside.
Remove the plant from the container and position in the hole. The top of the root system should sit level with the top of the soil. Carefully backfill the hole and water well.
If you are planting more than one verbena remember the plants have a spread of up to 24 inches. Check the spread of the variety you are growing, this information will be on the seed packet or the plant label, and space accordingly.
Planting in a favorable, full sun position encourages lots of flower clusters to form.
Planting in Containers
If you are planting in a container select a pot at least 6 to 8 inches wide. It should be clean and have drainage holes in the bottom. Planting in self watering pots allows you to create an attractive, low maintenance ornamental garden.
Some growers like to plant trailing varieties of verbena in hanging baskets. To do this, select a basket large enough to hold the plant as it spreads. Remember that baskets, once planted up and filled with soil, are very heavy. Place the baskets in a secure position to prevent them from falling. You can also try growing trailing or compact varieties as part of a living wall.
Add a layer of gravel or broken clay pots to the bottom of the pot. This helps to improve drainage. Fill the container with well draining, fresh compost. Mixing peat moss into the soil further helps to improve drainage. It also gives the plants a nutritional boost.
Make a hole or holes in the soil, one for each plant. Properly space the plants so that air can circulate freely.
Plant as above and gently fill in the holes. Firm down the soil and water well, until water begins to drain from the bottom of the container.
Place the containers in full sun positions, where they will receive lots of light and warmth.
Fill containers with well-draining compost. Soil that is too heavy can retain moisture causing roots to become overly saturated and rot.
Verbena Care Tips
Verbena flowers in the first year, if the growing conditions are favorable.
Regularly pruning the plant encourages flowers throughout the summer. If flowers are slow to emerge cut the plant back by about a fourth, fertilize lightly and water. Fresh flowers should emerge within a few weeks.
Tall varieties have surprisingly robust stems. This means that the plants rarely require staking. However, if you are growing in an overly windy position the plants may appreciate some support.
Remember to weed regularly around your plants. Weeds can take moisture and nutrients away from ornamental plants as well as smothering seedlings. There are a number of weed tools available to keep your flower beds problem free.
Once established the plants are largely drought resistant.
Regularly watering verbena plants encourages more flowers to form. Apply about an inch of water every week to the base of the plant. Remember, plants in containers require more frequent watering than those in beds or borders. Harvesting rainwater is a great way to keep plants hydrated without running up a large water bill.
While the plants can survive in dry conditions they do benefit from regular watering. Drought stressed or thirsty plants can struggle to thrive. They may also become a target for pests such as spider mites.
These plants struggle in wet or boggy soil. Plants in wet positions are also more likely to succumb to diseases such as botrytis blight.
Plants in containers benefit from the application of a slow release fertilizer once every two weeks. Alternatively apply a water soluble general purpose feed once a month.
Applying a slow release fertilizer helps to promote a strong growth habit. It also encourages the plants to flower in abundance.
Regular deadheading encourages more flowers to form.
Once flowering has finished, some gardeners choose to remove the dead stalks. Others allow them to remain in place for winter interest. If you choose to do this, remember to cut the stems back in early spring when new growth begins to appear. This is best done by making clean cuts with a garden scissors.
How to Over Winter Verbena Plants
To help your verbena plants overwinter place a mulch of well-rotted manure or straw around the base of the plants in the fall. This protects the roots from frosts. Gradually remove the mulch in the spring as the temperatures begin to rise.
How to Propagate
Verbena plants can be propagated from seed or from cuttings
Propagating from Seed
If verbena flowers are allowed to go to seed the plant will self-seed. This means that it returns every year, spreading through your garden. If you want to control the spread of the plant you need to harvest the seed pods.
To propagate from seed, allow the flowers to die on the stems. As the flowers fade they are replaced by brown seed pods.
Cut away the pods and dry them in a dark, airy place for about a week. To release the seeds, gently rub the dried pods. Store the seeds in a marked envelope until you are ready to sow.
How to Propagate From Cuttings
Propagation from cuttings is best done in late spring. This is when your verbena plants are most likely to root. Cuttings can also be taken during the summer months. These are often more robust but are slower to root.
Each cutting should be about 3 inches long. It should not have flowers on it. Remove all but the top two sets of leaves.
Plant the cutting in a container filled with a moisty, well-draining, gritty growing medium. Keep the soil moist. Placing in a propagator or plastic bag helps.
Cuttings usually root within 6 weeks.
Grow the cuttings on, undercover, until you are ready to transplant.
Common Pests and Problems
Verbena can fall victim to irritants such as leafminers as well as aphids, mites, whitefly, scale and thrips. Regularly inspect your verbena for signs of infestation. This helps you to deal with problems before they become major issues.
If you do need to treat an infestation always try to use organic pest control solutions. Chemical products can have a negative effect on the butterflies and pollinators that visit your verbena plants. Making your own insecticidal soap is just as effective as applying a chemical control and far better for the environment.
If the verbena plant appears leggy it is a sign that it is not receiving enough sunlight.
Powdery mildew is often caused by poor air circulation. Space your verbena plants so that air can circulate freely between then. Also try to avoid watering the foliage, water only the base of the plant. Damp foliage can create humid environments, which is a breeding ground for mildew and other diseases.
Foliage turning yellow is a sign that the plants are sitting in wet or poorly draining soil.
Companion planting is a great way to encourage growth and keep plants healthy. Basil, which deters thrips, dill, garlic and cilantro, which repel spider mites are all good companions. Chrysanthemums and daisies also help to deter pests and attract useful pest predators such as ladybugs.
Planting alongside lobelia or bronze fennel is a great way to support butterflies. Young swallowtail butterflies enjoy the foliage of bronze fennel while the adults harvest verbena plants.
One of the best plants for butterflies, the verbena is a reliable way to add color and interest to your garden. The versatile nature of these plants means that, as well as being a staple of the cottage garden, they can work in a variety of planting schemes.
A popular butterfly garden plant that also attracts hummingbirds, verbena looks particularly effective in mixed flower or cottage garden beds. The versatility of verbena means that it thrives in beds, containers and hanging baskets.
Easy to grow and care for, the tall, airy growth habit of verbena means that it is a great way to add structure to a garden. Flowering throughout the summer, adding a few verbena plants is also a good way to introduce color and attract wildlife.