Verbena rigida 'Polaris'

Named Verbena rigida after its upright habit, this front-of-the-border performer, although only a foot or two in height, can outshine almost everything else, particularly in late autumn sunlight. 'Polaris' is a dazzling, low-growing verbena produces three-branched candelabra of silver-blue flowers. The hundreds of tiny flowers found on each upright head will from June until October. This is a plant that gives great garden value.
Verbena rigida is an all round tough plant suitable for problem areas, it will tolerate full sun and sandy, drought-prone soils. Plant at the front of the border where it can be appreciated,
Associating well with grey and silver-leaved plants, it is wonderful used in generous drifts for infilling a traditional knot garden, it can also be used to line a path.

This jewel-like perennial is perfect for a sheltered, sunny, well-drained spot. Associating well with grey and silver-leaved plants, it's wonderful used in generous drifts for infilling a traditional knot garden.
The rigid flower heads of this Verbena mix well with soft, silky grasses that flop. The best combination is provided by the cream-white powder puffs of Pennisetum villosum, a grass of similar height which will also overwinter in the same well-drained conditions. The annual barley-like grass, Hordeum jubatum, is also excellent. It is a short-lived perennial for a hot spot and always happy to self-seed a little.

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.

• Awarded the RHS Award of Garden Merit
  Verbena rigida 'Polaris' was awarded the Royal Horticultural Society’s Award of Garden Merit (AGM) in 1993.

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.

Transplanting:
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.

Cultivation:
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.

Plant Uses:
Wildlife, Bee and Butterfly gardens. First year flowering, Gravel, City, Containers, Low-maintenance. Beds and borders, Cottage/Informal, Garden edging

Wildlife:
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.

Origin:
The genus contains well over 250 species plus many garden hybrids. All but two are found in Latin America. V. rigida is a native of Brazil and Argentina. It was introduced into Europe circa 1820 by Dr John Gillies, in an era when many South American plants were collected by copper-mining engineers setting up new businesses.
It soon dazzled and, being easily raised from seed, found itself bedded out in three grand French gardens - Versailles, Malmaison and Fontainebleau.

Nomenclature:
The genus name comes from the Latin Verbena, a classical name for certain sacred branches, probably of Verbena officinalis of Europe.
The species epithet rigida derives from the Latin "rig(id)" meaning stiff, referring to the erect stems.
Verbena rigida 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.