Verbena is a diverse and enchanting genus of flowering plants belonging to the family Verbenaceae, encompassing around 250 species distributed across the Americas and Europe, with the greatest concentration of species found in the tropical and subtropical regions of South and Central America. Ranging from low-growing, ground-hugging annual and perennial species to tall, airy, self-seeding varieties that weave gracefully through mixed borders, verbena offers an extraordinary range of garden uses and ornamental possibilities that have made it a firm favorite among gardeners worldwide for centuries.
The flowers of verbena are small, tubular, and five-petaled, arranged in dense, rounded or flat-topped clusters that collectively create a bold and eye-catching display of color that belies the delicate scale of the individual blooms. They appear in a rich and varied palette of colors including deep purple, violet, magenta, pink, red, white, and soft lavender, with many varieties featuring a contrasting white eye at the center of each tiny flower that adds depth and visual interest to the overall display. The long and prolific flowering season of most verbena species, extending from late spring through autumn, makes them outstanding value in any garden planting.
Among the most beloved and widely grown verbena species in gardens is Verbena bonariensis, the tall, airy, purple-flowered South American native that has become an iconic presence in contemporary garden design worldwide. Growing to four feet or more on slender, wiry, branching stems, Verbena bonariensis has a wonderful transparent quality that allows it to be planted in front of other plants without obscuring them, weaving through borders like a haze of purple that catches the light beautifully in the late afternoon sun and attracts clouds of butterflies throughout its incredibly long flowering season.
Verbena holds a long and distinguished history of medicinal and cultural significance across many civilizations. In ancient Rome and Egypt, verbena — particularly the species Verbena officinalis, known as vervain — was regarded as a sacred and powerfully magical plant used in religious ceremonies, healing rituals, and protective charms. Herbalists throughout the medieval period prescribed vervain for a wide range of ailments, and the plant retained its reputation as a herb of extraordinary spiritual and medicinal power well into the modern era, featuring prominently in folk medicine traditions across Europe and the Americas.
As garden plants, verbenas are remarkably versatile, adaptable, and rewarding to grow in a wide range of situations and conditions. Low-growing annual varieties such as Verbena × hybrida are outstanding in containers, hanging baskets, and window boxes, where their trailing habit and prolific flowering create spectacular cascading displays of color. Perennial species like Verbena bonariensis and Verbena hastata excel in mixed borders and naturalistic plantings, while ground-covering species like Verbena canadensis spread to form colorful, weed-suppressing mats in sunny, well-drained positions.
Verbena is an exceptionally valuable ecological plant that provides outstanding support for pollinators throughout its long flowering season. The dense flower clusters are particularly attractive to butterflies, which are drawn in remarkable numbers to verbena — especially Verbena bonariensis — making it one of the single most effective butterfly-attracting plants available to gardeners. Bees, hoverflies, and other beneficial insects also visit verbena flowers enthusiastically, and the plant’s long season of bloom from late spring through autumn provides a sustained and reliable nectar and pollen resource during the critical late-season period when many other garden plants have already finished flowering.
How to Grow Verbena From Seeds
- Understand the Different Types Before Sowing — Before starting verbena from seed, it is helpful to understand the key differences between the main types available. Annual hybrid verbenas (Verbena × hybrida) are compact, free-flowering, and ideal for containers and bedding, while Verbena bonariensis is a tall, airy, self-seeding perennial that excels in mixed borders. Each type has slightly different seed requirements and growing characteristics, so identifying which type you are working with before you begin will help you tailor your approach for the best possible results.
- Source Fresh, Quality Seeds — Always begin with the freshest, highest quality verbena seeds available from a reputable seed supplier. Verbena seeds can have variable germination rates even under ideal conditions, and using old or poorly stored seeds will only compound this variability and reduce your chances of achieving a satisfactory stand of seedlings. Check the seed packet date carefully before purchasing and choose seeds from the current or most recent season for the most reliable germination results.
- Cold Stratification Improves Results — Verbena seeds — particularly those of perennial species — benefit significantly from a period of cold stratification before sowing to help break their natural dormancy and improve germination rates. Place seeds in a damp paper towel inside a sealed plastic bag and refrigerate for two to four weeks before sowing. This cold and moist treatment mimics the natural winter conditions that verbena seeds experience in their native habitat before spring warmth triggers active germination.
- Start Seeds Early Indoors — Verbena has a relatively long growing period from seed to flowering plant and should be started indoors early in the season to ensure plants have sufficient time to develop and begin flowering during the current growing season. Sow seeds indoors ten to twelve weeks before the last expected frost date in your area. Starting early enough indoors is particularly important for annual hybrid verbena varieties, which need a long growing season to produce their best and most prolific flowering display.
- Prepare Seed Trays With Fine Compost — Fill seed trays or small pots with a fine, well-draining seed-starting compost that has been thoroughly moistened before use. Firm the surface gently to create a smooth, consistent sowing surface that will support even germination across the entire tray. A fine-textured, well-aerated seed compost provides the ideal growing environment for verbena seeds, giving them good contact with consistently moist growing medium without the risk of waterlogging that could cause seeds to rot before they germinate.
- Sow Seeds at the Correct Depth — Verbena seeds require darkness to germinate and should therefore be covered with a thin layer of compost or fine vermiculite after sowing, unlike some seeds that need light for germination. Sow seeds thinly across the moistened compost surface, spacing them as evenly as possible, then cover with approximately one-eighth of an inch of fine vermiculite or sieved compost. This thin covering maintains the darkness and consistent moisture that verbena seeds need while still allowing emerging seedlings to push through easily.
- Provide Warmth for Reliable Germination — Verbena seeds require consistently warm temperatures to germinate successfully and reliably, ideally between 65–75°F (18–24°C). A heated propagator is the most effective and reliable way to maintain these temperatures consistently throughout the germination period, particularly during the cooler early spring weeks when indoor temperatures can fluctuate considerably between day and night. Consistent warmth is one of the single most important factors in achieving good verbena seed germination rates.
- Be Patient and Persistent — Verbena seeds are notoriously slow, uneven, and sometimes frustratingly unpredictable in their germination, often taking anywhere from two to five weeks to sprout even under ideal conditions. Some seeds in the same tray may germinate within two weeks while others take considerably longer, resulting in a staggered emergence that can make it challenging to manage seedlings at similar stages of development. Maintain consistent warmth, moisture, and light throughout this period and resist the urge to give up on trays that appear slow to respond.
- Provide Light Immediately After Germination — As soon as the first seedlings begin to emerge, remove the propagator cover gradually and move trays immediately to the brightest available location or place them under grow lights for fourteen to sixteen hours per day. Verbena seedlings are particularly prone to becoming pale, weak, and leggy if they do not receive sufficient light from the earliest possible stage of their development, and etiolated seedlings rarely develop into strong, productive flowering plants regardless of the care they subsequently receive.
- Water Carefully to Prevent Damping Off — Damping off — a fungal disease that causes seedlings to collapse suddenly at soil level — is one of the most common and frustrating problems encountered when growing verbena from seed. To minimize the risk, always water from below by placing seed trays in a shallow tray of water and allowing moisture to be absorbed upward through the compost rather than watering from above. Ensure excellent ventilation around seedlings, avoid overwatering, and use fresh, sterile seed compost to give seedlings the best possible protection against this devastating condition.
- Prick Out Seedlings Into Individual Pots — When seedlings have developed their first pair of true leaves and are large enough to handle safely without risk of damage, carefully prick them out individually into small pots or cells filled with good quality multipurpose potting compost. Handle seedlings gently by their leaves rather than their delicate stems during this process, and water them in thoroughly after potting to help them settle quickly and comfortably into their new individual growing containers without experiencing significant transplant shock.
- Pinch Back for Bushier Plants — Once verbena seedlings are established in their individual pots and have developed three or four sets of true leaves, pinch out the growing tip of each plant between your finger and thumb to encourage the development of multiple side shoots and a naturally fuller, more branched, and more compact plant habit. This simple but highly effective pinching technique results in plants with significantly more stems, which ultimately means considerably more flowers and a much more impressive and abundant display at maturity.
- Begin a Regular Feeding Program — Once seedlings are actively growing in their individual pots and have developed a reasonable root system, begin feeding them every two weeks with a balanced, water-soluble liquid fertilizer diluted to half the recommended strength. As plants develop further and approach planting-out size, switch to a fertilizer with a slightly higher potassium content to encourage the development of strong stems, vigorous root systems, and the flower bud formation that will produce the prolific blooming display you are working toward.
- Harden Off Thoroughly Before Planting Out — Before transplanting verbena seedlings to their permanent outdoor growing positions, harden them off carefully and gradually over a minimum of ten to fourteen days. Begin by placing seedlings outside in a sheltered, partially shaded spot for just a few hours each day, increasing their daily outdoor exposure progressively until they are spending full days and eventually full nights outside. Thorough hardening off is essential for verbena, which can be sensitive to the transition from protected indoor conditions to the more challenging outdoor growing environment.
- Plant Out in the Right Position and Conditions — Once all risk of frost has completely passed and seedlings are strong, well-rooted, and fully hardened off, transplant them to their final growing positions in full sun with well-drained soil. Space annual hybrid verbenas eight to twelve inches apart in containers or borders, and space Verbena bonariensis eighteen to twenty-four inches apart in mixed borders where its tall, airy form can weave freely between neighboring plants. Water thoroughly after planting and keep the soil consistently moist during the first two to three weeks of outdoor establishment to help plants root in quickly and begin their long and spectacular flowering season without delay.