Every gardener is familiar with the willowy Verbena bonariensis, a tall lilac-purple vision beloved by butterflies. But there is a more dazzling, low-growing verbena which produces a three-branched candelabra of deep purple to magenta flowers.
Verbena venosa is a small and more densely flowered version which flowers for four or five months at a stretch. The dense 5cm (2in) clusters of purple-pink flowers are held in domed heads and emit a delicate fragrance through the hazy summer months.
The foliage has long toothy leaves that arch rigidly out from the upright flowering stalks. They will bloom from mid-spring right until the first cold of winter..
Verbena venosa is a brilliant addition to the garden. It is a bright and breezy specimen for beds and borders. Grow in full sun and in moderately moist, drained, fertile soils. They can also be used to line a path or to add height and interest to container planting.
For more than 100 years this species was considered only borderline hardy. Gardeners were recommended either to mulch the crown, or to collect and dry the tuberous roots. But warmer winters have persuaded us to leave dahlia tubers in the ground and relaxed our attitude towards other tender plants. V. rigida is now considered perennial, given good drainage. It comes through winters in most gardens with no special treatment at all. Often grown as an annual and discarded at the end of the flowering season. It can be sown directly, but results are far greater if the seeds are given favourable conditions during raising. Sow early spring for flowers the same year. Sowing to flowering approx 16 to 20 weeks.
Sowing: Sow seed at 18 to 21°C (64 to 70°F) in autumn or early spring.
Sow very finely onto the surface of pots containing moist seed compost. “Just cover” with a sprinkling of sieved soil (1/16th in) and cover the container with dark paper or similar as the seeds need the dark to germinate. Place the container in a dark place. Maintain an optimum temperature of 15 to 18°C (60 to 65°F)
Keep moist, watering from the base of the container but do not saturate the compost. Germination is usually around 14 to 28 days, but may take up to 90 days to finish germinating (especially if seeds haven’t experienced cold stratification).
Remove the cover once they begin to germinate to allow air to circulate (otherwise they may suffer from damping off) and reduce the temperature to around 15°C (60°F), keep in light but not strong sunlight, a warm kitchen windowsill is often sufficient.
Thin (prick out) seeds as they become large enough to handle, leaving the seed trays in tact for other seedlings that may germinate later. Use 7cm (3in) pots containing well drained compost mix. You can add 10 to 15% horticultural sand (that doesn’t contain salt) to a regular compost to achieve this.
Harden off young plants gradually for 10 to 15 days before planting out, Pinch back when first planting to encourage branching. Plant 45cm (18in) apart in a sunny position in ordinary garden soil. (Verbena is susceptible to the fungus mildew if planted in a wet, shady locale.) In poor soil it is worth incorporating some organic matter before planting.
Water deeply to encourage roots to grow deeply, resulting in a healthier, more drought tolerant plant. Avoid overhead watering if possible. Remove the faded flowers for a better following flowering.
Because it is borderline hardy, plants may be damaged by severe winter frosts. In winter mulch around the base of the plant with a deep, dry mulch to help protect the plant.
It is a short-lived perennial that self-seeds; the resulting seedlings are stronger and more drought-tolerant than those that are transplanted. Any plants lost to frost are normally replaced by their offspring.
They prefer dry, light and airy cultivation. Give the plants space and transplant any self sown seedlings that are growing near to each other. Verbenas do not require a particularly rich soil or fertiliser but will benefit from a light feed in spring.
Wildlife, Bee and Butterfly gardens. First year flowering, Gravel, City, Containers, Low-maintenance. Beds and borders, Cottage/Informal, Garden edging
Verbenas are beneficial for attracting wildlife, particularly butterflies.
It attracts: Brown Argus, Comma, Essex Skipper, Green-veined White, Large White, Meadow Brown, Painted Lady, Peacock, Red Admiral, Small Copper, Small Tortoiseshell, Small White and Hummingbird Hawk-moths.
The genus contains well over 250 species plus many garden hybrids. All but two are found in Latin America.
The genus name comes from the Latin Verbena, a classical name for certain sacred branches, probably of Verbena officinalis of Europe.
The species name venosa (also venosum and venosus) is from the Latin and means conspicuously veined.
Verbena is member of a genus of perennial herbs which are sometimes known by the ancient name Vervain which is thought to be derived from the Celtic words fer meaning to remove and faen meaning stone, referring to its use in treating bladder stones.
- Additional Information
Packet Size 75mg Average Seed Count 100 Seeds Family Verbenaceae Genus Verbena Species rigida Cultivar venosa Common Name Hardy garden verbena Other Common Names Large-veined verbena, Veined verbena, Stiff Verbena Hardiness Hardy Perennial Hardy Borderline hardy, often used as an Annual. Flowers Deep purple to magenta Natural Flower Time June until October Foliage Toothed mid green Foliage Height 45cm (18in) Spread 30cm (12in) Position Prefers full sun, but tolerates dappled shade Soil Well-drained, moist, moderately fertile soil Time to Sow Sow seed at 18-21°C (64-70°F) in autumn or early spring. Growing Period Sow early spring for flowers the same year. Sowing to flowering approx 16 to 20 weeks. Germination Usually around 14 to 28 days, but may take up to 90 days to finish germinating