How to Plant, Grow and Care For Verbena

Verbena, sometimes referred to as ‘vervain,’ is a vividly flowering family of plants that tolerate high heat and blooms all season. It is commonly used as a low-growing bedding plant or container accent and adds a rainbow of colors to the garden. Verbena also attracts butterflies and beneficial predatory insects.

Centuries ago, verbena was considered sacred due to its healing properties. Over many years, these once “holy” plants have been modified and adapted into the ornamental varieties we see today across nearly 150 species of verbena!

New cultivars have been bred to resist disease and withstand many climates and conditions. These modifications and the ability to thrive in tough climates are part of what helped verbena earn its title as one of the National Garden Bureau’s annuals of the year in 2022. 

Cultivation

There are many varieties of garden verbena at our fingertips once the spring weather has warmed. Over the years, verbena genetics have changed to help them adapt to all kinds of soils and climates. 

It’s no wonder these easygoing plants are among the most popular annuals today. The vivid flowers they produce are the cherry on top of their durability and rigor.

Propagation

Verbena is generally propagated by vegetative cuttings. Seeds are available online and in some stores, but they can be a bit tricky to get started, especially for gardeners that don’t have a greenhouse or a controlled seed germination system. 

Whether you are propagating by seed or cutting, ensure you have a warm and humid environment. This will aid in seed germination and rooting. 

Seeds

In warmer climates, verbena seeds can be directly sown into the ground in spring or summer. They prefer warmer temperatures to germinate, and you won’t have much luck getting these seeds to sprout if temperatures are below 60-65 degrees Fahrenheit. Just barely cover the seeds with soil (they’re tiny!) and keep the seed starting mix damp to the touch.

However, it’s important to note that while they like it warm to pop out of the ground, they need a little cold, too. Cold stratification can be quite beneficial for verbena seeds!

Verbena seeds take quite a while to sprout after planting (sometimes almost a month). Starting seeds indoors is more common than directly sowing outside, so consider the timeframe when planting. You will want to plant these seeds indoors 10 to 12 weeks before your expected last spring frost. This date is different depending on what zone you live in.

Cuttings

Verbena is generally propagated from cutting because it is much faster and more reliable than seed germination. Professional growers use vegetative cuttings to produce the plants we purchase in garden centers, but you can take cuttings at home too! 

Take cuttings in the morning when the plant tissue is turgid. Dip the ends into water and then into a powdered rooting hormone to speed up root production. Keep stem cuttings moist and in a warm environment. Once rooted, a diluted fertilizer application will help accelerate rooting and growth. 

Planting

Verbena is very low maintenance, and once planted, it requires little to no extra care. As mentioned before, verbena is very sensitive to cool temperatures, so it is important to plant living verbena plants outdoors only once the nighttime temperatures stay above 50-55 degrees Fahrenheit.

Transplanting

If you are transplanting seeds or cuttings you propagated yourself, you must harden off these plants before planting them outside. Hardening off helps acclimate young plants to the outside environment by gradually introducing them outdoors over a few weeks. 

Harden off plants by setting them outside for a few hours each day. Start with one or two hours in the shade on the first day of hardening off. Each day, gradually increase the time period and amount of sunlight the plants receive. Once they are familiar with full sun and the outdoor temperature, you are ready to plant.

To transplant plants from their plastic containers, you will need a few tools and a super sunny location:

1. Pick a full-sun location.
2. Use a shovel or broadfork to break up compacted soil and amend it with compost.
3. Dig a hole a couple of inches deeper and wider than the plastic pot.
4. Loosen up the plant’s roots by rolling the container in between your hands a few times.
5. Gently remove the plant from its the container and set it in the hole.
6. Backfill with the soil you dug up.
7. Water it in thoroughly.
8. Water frequently for the first week or two to help the plant adapt to its new environment.

How to Grow

Verbena is an easygoing plant that does not require much care once planted. Like most other full sun annuals, occasional deadheading will help increase blooms. Otherwise, verbena is a breeze to grow, and no extra care is required!

Sunlight Requirements

Verbena requires as much sun as possible. If the plant receives even partial shade throughout the day, the leaves will begin to fade and struggle to produce flowers.

Ensure the planting area receives at least 6-8 hours of direct sunlight and won’t get shaded by nearby trees, shrubs, or structures. 

Soil Requirements

Verbena prefers fertile, well-draining soil that allows the roots to dry out between waterings. An all-purpose potting mix is best for planting this flower in containers. 

If planting in the ground, test your soil drainage. You may need an amendment if you pour water over the soil and it takes a few minutes to drain. Amendments such as compost or decayed manure can help break up the soil and improve drainage. 

Water Requirements

Native to warm climates and dry prairies, verbena thrives in dry soils. Water containers and plantings thoroughly, then allow the soil to drain and dry out. They do not like to remain moist for too long, so it is pertinent to only water when necessary. Your hand is the best gauge of soil moisture. Stick a finger a few inches into the soil near the base of the plant.

• If the soil feels dry or crispy, it’s probably time to water.
• If the soil feels slightly moist or sticks to your finger, let it dry out a bit before watering.

Climate and Temperature

Verbena is notorious for its ability to bloom throughout the warmest parts of the growing season. They are sensitive to cool temperatures and prefer to be grown above 50 degrees Fahrenheit. 

In humid climates, verbena can be susceptible to powdery mildew. Fortunately, most modern varieties have been bred for resistance to this foliar issue. 

Fertilization

While verbena doesn’t require heavy feeding, it can benefit from fertilization occasionally. Once every couple of weeks is the perfect amount.

To save time and effort, I like to use a slow-release fertilizer. Slow-release organic fertilizers can feed plants over a long period of time, supplying a small amount of nutrients with each watering. 

This plant isn’t a heavy feeder, so it won’t hog any fertilization from surrounding plants. 

Maintenance

With the tendency to spread and grow long stems, these plants can sometimes become unruly and sprawl into walkways or in unwanted locations. Light pruning is an easy way to keep the plants tidy and help to extend the blooming season. 

Spent blooms can also be lightly pruned to encourage new flowers and keep the plant clean, although this is entirely up to your discretion. Towards the middle-to-end of the growing season, verbena develops woody stems. Sometimes these stems can host flowers that go to seed or turn brown. You can easily cut them off.

When pruning, do not remove more than one-third of the plant at a time. This can harm the plant and can hinder growth and blooms, especially in extreme temperatures.

Varieties

There are so many varieties of garden verbena on the market today. Here are some stellar standouts!

‘Empress Flair Burgundy Star’

This beautiful variety offers a striking burgundy/cream bicolor flower. Plant it in hanging pots or patio planters with a Juncus grass and sweet potato vine for one of my favorite combinations.

‘Superbena Peachy Keen’ 

This peach-colored variety is quite a summery treat. I love to plant it with dark foliage, such as sweet potato vines or cannas for a vivid pop of color. It blooms prolifically, even throughout the heat of the season, and is very forgiving when it comes to drought.

‘Verbena Lanai Lime’

‘Lanai Lime’ blooms in a pale green color and fades to a pastel lime shade in the heat of the season. This variety is such an interesting color and resembles the light green hydrangeas you might have seen in landscapes. 

These are just a few of the many many varieties available today. There is surely a color that will catch your eye this season.

Companion Plants

Most full-sun annuals make great companions to verbena. Due to its adaptability and low-maintenance personality, this flower is very versatile in the garden. Plant it in pots with petunias or calibrachoa or with full-sun grasses and other foliage. 

In containers, verbena will spread, but not in a manner that will take over the plants around it. It will grow in between other plants and trail out of hanging pots or planters.

The most important thing to remember if planting verbena with other plants is to make sure all plants in the pot or area love full sun. Without a lot of sunlight, it will not flower. So don’t pair it with shade-loving plants. Avoid planting in an area where it could get shaded by a tree or structure.

Pests and Diseases

Although verbena is easygoing, it can occasionally fall subject to certain pests and diseases. Let’s cover a few things to watch out for when growing these vibrant plants.

Diseases

Plant diseases can be quite challenging to eradicate once they are discovered, so preventative methods are most effective. This is especially important when it comes to root diseases because they are harder to detect in the soil. 

Root Rot

When soil stays too wet, verbena can succumb to root rot. This fungus can develop from overwatering or planting in soil without proper drainage. Root rot starts at the base of the roots and will rot the plant tissue. Eventually, it will work its way up the plant and start to affect tissue above the soil line, turning stems and leaves brownish-black.

The best way to treat root rot is to carefully unpot, prune off rotten roots, and repot your plant into fresh, healthy soil.

Botrytis Blight

Botrytis blight is a grayish mold on stems and foliage. If not appropriately treated, botrytis will kill the affected plant tissue causing it to turn a blackish-brown color. It forms in humid or wet conditions where plant tissue stays wet for long periods of time.

Treating botrytis blight can be quite a pain. First, remove affected plant parts and dispose of them in the trash. Do not compost. You may use a fungicidal spray to help prevent the mold from spreading. 

Powdery Mildew

Powdery mildew is one of the most commonly seen issues among home gardeners. This white powdery substance also occurs in wet and humid conditions, forming atop old and new leaves.

Homemade remedies can help eliminate powdery mildew, such as baking soda dissolved in water. However, copper fungicide might be the best option in more severe situations.

Pests 

Verbena has slightly sticky stems and leaves, so pests generally aren’t attracted to them. However, in certain circumstances, some insects will attack these plants and cause stress. You may see some pests on your verbena plants: spider mites, aphids, and lace bugs.

Spider Mites

If your Verbena leaves look faded and speckled yellow, this could be spider mite damage. Spider mites attack the undersides of leaves and suck the nutrients from the plant’s leaves and stems. If left untreated, spider mites can seriously damage and kill a plant. An insecticidal soap or spray is a great way to eradicate these pests. 

Aphids

Aphids hang out on the underside of plant leaves. They are most often tiny green or yellow bugs, but in some life stages, they are white. They feed on plant nutrients and can be quite a nuisance if not treated properly.

Removing damaged foliage is often necessary, and an insecticidal soap treats them best in severe cases. If you would like to stick to more natural methods, sometimes spraying these insects with hose water will remove them from plant tissue, but generally doesn’t eradicate the problem due to their ability to stick to the plant.

Lace Bugs

Lace bugs are small light brown bugs that have transparent lacey wings. They feed on plant foliage creating foliage that looks stippled and light-bleached in color. 

Treating these pests with neem oil is often an effective method. In the early stages, lace bugs appear as tiny blackish-brown dots. If you suspect lace bugs on your plants, try eradicating them immediately to prevent nearby plants from being affected.