How to Grow Verbena Bonariensis

Perennials — Verbena bonariensis

Verbena bonariensis is an outstanding tall perennial that adds a sense of airiness and sparkle to the perennial border.

Jimmy Hendrix could have been singing about this lovely plant when he penned ‘Purple Haze’. Flower heads of tiny lavender to purple flowers adorn the tips of the stiff flower spikes and attract butterflies from miles around. While each blossom is small, the display is impressive.

The plant form of tall verbena is stiff and upright. The square stems are sparsely covered in long, narrow toothed leaves. Stems emerge from the base to form a twiggy clump.

Verbena bonariensis is an easy-to-grow pollinatior-friendly perennial.

How To Use Verbena bonariensis In The Landscape

I like to use this tall verbena as a floral filler in perennial borders to break up the mass and heaviness of more solid plants or perennials and annuals that have large flowers. The interesting branched flower spikes blend well with most other flowers.

Verbena bonariensis is also looks stunning when planted flanking a garden path. The head-height flowers provide spatial definition without sacrificing the ability to see through the lacey branches.

Verbena bonariensis Plant Combinations

Combine Verbena bonariensis with white Gaura lindheimeri (a perennial plant) of sparkling white Cosmos ‘Purity’ for a pleasing purple and white summer floral display.

Verbena bonariensis combines well with white cosmos and perennial gaura.

Plant Facts:

Genus: Verbena

Species: bonariensis

Common Name: Purple-top Verbena

Plant Type: Herbaceous Perennial

Bloom Season: Spring till frost

Light: Full Sun (6 or more hours)

Moisture: Well-drained soil required, drought tolerant

Height and Spread: 6 feet tall x 2 feet wide

Garden Location: Back of bed or border

Soil Type: tolerant (sandy, loam, or clay)

Where To Buy Verbena bonariensis

Verbena bonariensis can be purchased as a living plant in a four-inch or one gallon pot in spring or summer from many better nurseries and independent garden centers. Plants establish quickly and reach their full potential by the end of the growing season.

You can also start Verbena bonariensis from seed. It is best to start seeds indoors in a warm bright area or under LED grow lights. Seeds germinate in a couple of weeks and plants will begin to flower in early summer. Unlike many perennials, this species blooms the first year when grown from seed.

Verbena bonariensis flower closeup.

How To Grow Verbena bonariensis From Seed

Seed starting for Verbena bonariensis is simple provided you meet it’s rather modest requirements. Start seeds 8 to 12 weeks before your last frost.

Sow seeds indoors under LED grow lights in flats or cell packs and use a high quality seed starting mix. Seeds germinate in two to four weeks. For best results, provide bottom heat during the day. I use a timer to turn off the seedling heat mat at night. The warm days and cooler nights stimulate germination. However, some gardeners prefer to cold stratify the seeds with damp compost in the refrigerator for four weeks and then plant in flats to hasten germination. I find cold stratification no be unnecessary, but it may help if your seeds do not germinate using the first method.

Sow seeds in cell packs or flats and firmly press seed into the soil. Barely cover the seeds as they require light to germinate. Keep the seed starting soil slightly moist. Too much moisture inhibits germination and can cause the seeds to rot.

Transplant tall verbena seedlings after all danger of frost has passed. Solace seedlings 18 to 24 inches apart. Plants grow quickly as spring heats up and bloom in approximately three months.

Use Verbena bonariensis as a Cut Flower

Verbena bonariensis has been used as a filler in this bouquet.

Tall vervain makes a pleasing, long-lived cut flower for bouquets and flower arrangements. Harvest flower stems for cut flowers when the outer couple of rows of flowers have opened. More small purple flowers will continue to bloom in the vase. Use with similarly colored flowers for a monochrome display of purple and lavender, add white cosmos or baby’s breath to add a little sparkle, or contrast with hot colors to create a pleasing display. Verbena bonariensis looks great when combined with richly colored orange dahlias for a late summer table centerpiece. Floral preservative extends vase life.

Verbena bonariensis Varieties

Unlike many other verbena species, there are not a lot of horticultural varieties of this species available. The wild form of the species is most commonly grown. However, selective breeding has created a shorter version called ‘Lollipop’ high grows to only half the height as the standard variety.

‘Lollipop’ — shorter than the species. Purple flowers bloom on 24-36” stems.

Frequently Asked Questions

Is Verbena bonariensis invasive?

This species of verbena tends to reseed in warm climates and may become weedy in some gardens. Just pull out unwanted seedlings and let the other ones grow and bloom. However, Verbena bonariensis is more vigorous in the Deep South where is does possess invasive potential. Avoid planting this species next to wild areas where it may spread unwanted and displace native plants.

How Do I Collect Verbeena bonariensis Seed?

Collect Verbena bonariensis seed by shaking the seed head into a container of pierce of paper.

Verbena bonariensis seed can be collected during late summer and fall. Since the flower heads bloom over an extended period, it is best to shake seed from the ripened seed pods into a container while the the flower spikes are still attached to the plant. Seeds are small and dark. Store in a dark, cool, and dry place until the seeds are sown.

Is Their A Shorter Variety of Tall Vervain?

There are two varieties of dwarf Verbena bonariensis.

The ‘Lolipop’ variety of Verbena bonariensis grows to about half the size of the regular form and has been around for a while.

The plant breeders at Proven Winners have released an even more compact variety of Verbena bonariensis called Meteor Shower. Meteor Shower® Verbena bonariensis ‘INVEBPUTOW’ USPP 27,722, Can 5,507. This cultivar grow only 20-36” tall and is great used in pots.

Can I Sow Verbena Directly In The Garden?

The seeds of verbena bonariensis can be down after danger of frost has passed in spring. Press seed into the soil and lightly cover. Keep moist until germination occurs. Space groups of seeds 12 to 24 inches apart.

How Hardy Is Verbena bonariensis?

Verbena bonariensis is a hardy perennial in USDA zones 7-10. In colder climate zones, it can be grown as an annual flower. Do not cut off the old stems until you see new growth in spring in USDA zone 7 as the old stems provide some degree of winter protection.

When Can I Cut Back Verbena bonariensis?

It is best to leave old stems of this species on the plant through the winter. In addition to providing some winter protection for the roots, the stiff ornamental stems add winter interest to the garden.

When Does Verbena bonariensis Flower?

Mid-summer through autumn is the peak blooming period for Verbena bonariensis. Flowers emerge over a long blooming season from terminal flower heads held erect on stiff stems.

How Do I Plant Verbena bonariensis?

Plant tall verbena from pots after all danger of frost has passed. Dig a hole as deep as the pot and two to three times as wide. Add a little compost into the backfill soil. Water deeply to remove any air pockets and to hydrate the surrounding soil to encourage the roots to explore their new home.

Can Verbena bonariensis Seedlings Be Planted Before My Last Frost?

It may be possible to provide frost protection for newly planted verbena seedlings by using frost cloth, but it is far better to wait until the danger of frost has passed and the soil has begun to warm. It is less work to grow plants using their natural cycle than trying to intervene when frost threatens. Patience can be a gardener’s best friend.

Where is The Native Habitat of Verbena bonariensis?

Verbena bonariensis is native to warm, dry areas of Argentina and surrounding countries in southern South America. The specific epitaph‘bonariensis’ alluded to the city of Burlenos Aires.

Will Verbena bonariensis Attract Pollinators?

Butterflies and other pollinators are attracted to Verbena bonariensis.

Verbena bonariensis is an excellent plant for attracting butterflies and pollinating insects into the garden. The small, nectar-filled flowers are attractive to many beneficial insects.

Is Verbena bonariensis An Annual or Perennial?

Verbena bonariensis is a hardy perennial in USDA zones 7-11. It is grown as an annual in USDA zones 3-6.

Do You Have To Deadhead Verbena bonariensis?

Since each flower head produces a lot of flowers over an extended period, it is not necessary to deadhead older flowers as is done for many other Collin annuals and perennials. Only cut stems that have gone completely brown during the growing season. Wait to cut stems to the ground until new growth initiates in spring. Verbena bonariensis is a low-maintenance perennial that requires minimal deadheading to keep its appearance looking good.

What Fertilizer Do You Use For Verbena?

Verbena bonariensis does best when fed with a thin top dressing of compost. This species does best in souls of modest fertility. Excessive fertilizer encourages rank growth and can make the typically stiff stems floppy and reduce the flower quantity. compost or organic fertilizers are the best products to use on tall vervain.

How Do You Prune Verbena bonariensis?

In areas where Verbena bonariensis is a root-hardy perennial garden plant, prune the dead top growth to 6 inches above the ground when you see new growth emerging.