|Verbena hastata subsp. var.||American Blue Vervain, Blue Vervain, Swamp Verbena|
Verbena hastata (Blue Vervain or Swamp Verbena) is a flowering plant in the vervain family, Verbenaceae. It is a herb with opposite, simple leaves which have double-serate margins, borne on stiffly erect, branching square stems. The flowers appear in summer and are purple.
The plant prefers light (sandy), medium (loamy) and heavy (clay) soils and requires well-drained soilpf. The plant prefers acid, neutral and basic (alkaline) soils. It cannot grow in the shade. It requires moist soilpf.
Seed - sow early spring in a greenhouse or cold frame and only just cover the seed1. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in the summer. Division in spring. Larger divisions can be planted out direct into their permanent positions. We have found that it is best to pot up smaller divisions and grow them on in light shade in a greenhouse or cold frame until they are growing away well. Plant them out in the summer or the following spring. Basal cuttings in early summer. Harvest the shoots with plenty of underground stem when they are about 8 - 10cm above the ground. Pot them up into individual pots and keep them in light shade in a cold frame or greenhouse until they are rooting well. Plant them out in the summerpf.
Pests and diseases
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963