As a perennial in USDA plant hardiness zones 8 to 11, Shrub verbena (Lantana trifolia) is an evergreen broadleaf shrub that grows as an annual in colder regions. The shrub verbena can be trimmed back if it gets too big, and the plant grows 2 to 5 feet tall.
Pruning Shrub Verbena
Verbena like to be pruned in the spring, but if the plant has grown too large, it can be pruned during the growing season. Bachman’s recommends cutting the plant back to a third of its height in the spring. The shrub’s health and vitality may be compromised if it is cut back even farther.
Verbena is a fast-growing shrub that can reach heights of up to 5 feet. It’s possible to limit height by trimming down the tips of this plant during summer if it’s too tall for your landscape. You can also expect to see more pink, purple or white blooms from this shrub all year long as a result.
Pruning should be halted for the season. Pruning and new growth might reduce a plant’s ability to resist cold weather when the temperature drops.
Pruning Tips and Considerations
The tools you’ll use to prune shrub verbena should be thoroughly cleaned and disinfected before you begin. It is easy to spread fungus and other infections from other plants in your landscape to these plants, despite the fact that these plants rarely suffer from illness.
Start by cleaning the blades of your shears of dirt, sap, and other debris. Afterwards, wash and dry the blades. The University of Florida IFAS Gardening Solutions recommends soaking the instruments in a 10 percent bleach solution for 30 minutes before thoroughly rinsing them in clean water.
Wearing gloves when pruning verbena is a smart idea. According to North Carolina State University Cooperative Extension, sap from the plant can cause skin irritation and contact dermatitis. Human and animal health can suffer as a result of eating the plant, so keep curious dogs and toddlers indoors while you work with the plant.
Pruning Other Verbena Varieties
Verbena is a common name for a variety of flowering plants, both annual and perennial (Verbena spp.). Depending on the species, they can withstand USDA zones 4 to 11. Verbenaceae is the family of plants that includes shrub verbena. Even though they aren’t often cultivated as shrubs, some can benefit from pruning and cutting back, but this isn’t normally necessary to keep healthy plants.
In the same way that shrub verbena is pruned, verbena blooms can be pruned as well. Remove dead or damaged branches and stems as soon as you discover them.
The Bachman’s website says that if you are cultivating an annual verbena species, you can cut back up to a fourth of the stems when they die back. Pruning perennial plants is more common. Twice or once during the growing season, you can trim the stems to a quarter inch.
Things You Will Need
- shears for pruning
How to Prune Verbena
Verbenas brighten up the look of any garden. The pruning of verbena plants is less often than that of other herbs and perennials, but it is necessary to keep the plants tidy and encourage new development. Early spring is the time for the most intensive pruning. Remove portion of the plant’s height in the summer to enhance flowering. Seed heads and dead blooms can be removed in the autumn. However, over-pruning your verbena plant could limit its growth.
Cutting Back in Early Spring
Wait until the spring to witness new growth. After the last frost, this is usually when it happens. New green shoots may be sprouting from the base of the plant, as well as new leaves on the stems. This is an indication that you need to reduce your consumption.
Remove any dead vegetation that is close to the surface. Look for dark or drooping stems or growth that is on the ground. Remove all of the dead vegetation from the ground.  You can either compost or dispose of these trimmings.
- All that’s left are the stems, which only need to be 2 inches long (5.1 cm). If you cut the plant near to the ground, it will immediately regrow. You should cut slightly above any new shoots that emerge from the old stems at the ground.
- Protective apparel, such as gloves, should be used while trimming in the garden. The leaves should be trimmed if they show signs of mold or discoloration, as these could be signs of disease.
Get rid of any seedlings. Keeping the plant from reproducing is a good thing. Your garden could get overrun by Verbena’s seeds before you know it. Look for cross-shaped seedlings at the base of your plant. If you don’t want them to grow, remove them from the ground.
Encouraging New Growth in Summer
Begin planting after the first summer blooms appear. There are a few times a year when this happens. Trimming the first blooms of verbena plants can prevent the plant from producing more blooms during the summer.
While the plant’s early blossoms are still in situ, don’t be hesitant to give it a trim. You’ll have flowers all summer and into the fall if you prune it back early.
Cut the entire plant down to one-fourth of its original size. Gardening shears or hedge trimmers can be used to cut back overgrown vegetation. When pruning, start at the top of the plant and work your way downwards. New blooms and growth will replace the old growth in 15 to 20 days.
- After the initial bloom, this is usually all that has to be done.
- Keep your hands and arms covered with gloves and long sleeves when trimming the plant.
Pruning the plant’s tips should continue throughout the summer. Trimming verbena to keep it from overgrowing is a good idea because of how quickly it grows. Controlling growth can be done by snipping the ends of your plants by around 2 inches (5.1 cm).
- For best results, you should perform this 2-3 times a season or as needed.
- Plants are referred to as “tipping” in this context. Verbena plants that are spreading or spotty will have a fuller, bushier appearance if you use this technique.
Powdery mildew should be removed from any leaves. If you have a wet summer, you may need to remove any powdery mildew growth from your verbena plants. Make a point of inspecting the leaves for white, powdery spots. Pinching or cutting off a branch if you notice any leaves.
- When pruning infected plants, use rubbing alcohol to disinfect your shears.
- Powdery mildew can be eradicated by spraying your verbena with fungicide or neem oil.
Deadheading in Autumn
4-6 weeks before the last frost, remove all of the deadheads from the plants. Find out when the final frost normally happens in your area by consulting an almanac or a weather service. Deadhead early in the fall if you’re not sure when it is.
Make sure to remove any wilting flowers from the base. To remove drooping, dying or shrivelled flowers from your garden, cut them off at the root. You can also twist the stem and remove the blossoms or seed heads by pinching them. Compost them or toss them in the garbage.
If you don’t want the verbena to self-propagate, don’t leave seed heads on the plant. A flower’s seed heads are found in its base, after all of the petals have faded or fallen off. The seeds of your verbena will not germinate if you remove the seed heads. Don’t remove the seed heads if you want your verbena to take over your entire garden.
- Allowing wild verbena to spread means you can never completely stop it, but the new seedlings may be more resilient to dryness than verbena transplanted in this way.
- Seed heads can add a burst of color to a winter garden if they are left in place. Remove any seedlings when you prune back the plant in spring if you prefer this look.
To help the plant survive the winter, avoid doing extensive pruning on it in the autumn. In the fall, it’s a good idea to conduct some light trimming, such as deadheading, but don’t go overboard. The verbena will be able to withstand the colder months thanks to this. Pruning can wait until the spring of the next year.
Trimming Annual Verbena (Tender)
Regular deadheading or trimming of annual verbena encourages new growth and blossoms. When annual verbena plants have grown sparse or straggly and have stopped flowering, I only trim them if necessary. The plants get a mild trimming at this time, with scissors or bypass hand pruners, up to one-fourth of their branch/stem length. After cutting, follow the product label’s instructions for applying a floral fertilizer.
Trimming Perennial Verbena (Cold Hardy)
Sharp scissors or bypass hand pruners can be used after winter to remove any damaged or dead plant portions from perennial verbena in cold locations where the temperature drops below freezing. After cutting, follow the product label’s instructions for applying a floral fertilizer.
Trim your verbena’s branches/stems back by one-fourth of their length after the huge spring blooms, two to three times per summer. New growth and blossoms are encouraged as a result. Apply a floral fertilizer if your plants appear to be in need of a pick-me-up.
Growing Verbena Plants
The shorter verbena varieties in purple, red, blue, and pink are the most widely known. The combination of verbenas and other annuals creates a stunning effect. Your garden will soon become a haven for butterflies, bees and other pollinators if you put them out for them.
However, Verbena can brighten up any room, indoors or out – even if it is just a potted plant. Verbena, dusty miller, and red-orange marigolds are some of the best ways to spruce up your greenhouse or garden. Despite the fact that these hues are ideal for summer, they will still look great in the fall.
Taking Care of Your Verbena Plants
Easy to grow verbena plants require only well-drained soil, six hours of sunlight, and an inch of watering every week. Unlike other resilient plants, verbena suffers if its care is not constant, which is frequent for annuals. If you neglect your verbena for more than a few days at a time, it may spend weeks without producing any flowers at all, and the foliage will become unappealing.
When growing verbena in the ground, the roots will be able to develop deep enough into the soil to solve their problems. Container-grown verbena, on the other hand, necessitates more frequent attention due to their secluded location.
2 Ways to Trim Verbena Plants
It doesn’t matter whether your verbena is an annual or a perennial; there are two methods for trimming it properly.
For annual verbenas, you can trim them regularly throughout the growing season to promote new growth and flowers. A good rule of thumb for trimming your verbena is when it’s drooping and straggly or no longer blooms.
Use sharp scissors or gardening shears and trim them about ¼ of their branches and stems. Apply flower fertilizer after trimming and be sure to follow the directions on the product label.
Temperatures that fall below freezing support the growth of perennial verbenas. After the winter has past, prune your verbena plants by removing any wilted or dead plants with sharp scissors or gardening shears. Flower fertilizer should be used in the same manner as with annuals.
During the summer, when the spring flowering has finished, you can trim your verbenas two or three times. Remove roughly a quarter of their length to encourage new growth and flowering. Flower fertilizer can also be used if your plants appear droopy and sickly.
It’s important to remember that perennial verbena just needs a light trimming in the fall. It is, however, possible that this will delay dormancy and weaken your plant’s resilience. Perennial verbenas should be pruned 45 days before your area’s first frost date.
Reasons Why You Should Consider Growing Your Plants in a Hobby Greenhouse
There are numerous benefits to growing your plants in a hobby greenhouse, including the following: Gardening in a greenhouse has many advantages, including the following:
Protect from harmful insects
Most prevalent insects that attack verbenas include gall midges and leafminers as well as aphids and caterpillar mites. Whiteflies are also a problem. Apply insecticidal soap to the affected region if you have already noticed an infestation. Pests that can harm your plants are less likely to be attracted to them if you keep them in a greenhouse.
More space for planting
Using a little greenhouse to grow verbenas or other plants if you don’t have enough room is an option. Patios, decks, balconies, and even tables can all benefit from the addition of small greenhouses. Small greenhouses, despite their size, are just as effective as larger greenhouses.
Create a microclimate
Regardless of the weather, you may grow food and flowers in a tiny greenhouse. The optimum growing climate within your greenhouse can be created by using grow lights, heating and cooling equipment, or even natural heaters and coolers.
Protect from bad weather
In the blink of an eye, your garden can be ruined by heavy rain, high winds, drought, and erratic weather. Keeping them in a greenhouse protects them from the unpredictable weather conditions outside the building. As soon as the weather warms and the spring season begins, you can transplant them into your garden if you choose.
The Bottom Line on How to Trim Verbena
After learning how to trim verbena, it’s crucial to keep in mind and adhere to the advice given above. Verbena plants may be grown and cared for so that you can enjoy their gorgeous blooms for many years to come.