Blue oat grass
This is a superb ornamental grass which originates from central and SW Europe. It is hardy and evergreen with blue-grey leaves which contrast well with other ornamental grasses which grow to a similar height.
H. sempervirens is a tuft forming perennial which forms a weeping mound of flat or tightly rolled leaves which can be up to 9in long. In early to midsummer stiff upright stems of flowers appear with straw coloured and purple marked spikelets. These can be 7in long on stems that reach up to 4ft in height. The overall width of a mature clump might be up to 2ft making this an imposing grass in the herbaceous border alongside Miscanthus or Stipa. Stipa tenuissima grows only to a smaller height but the contrasting colours between blue and green makes for a striking effect. Miscanthus ‘Gracillimus’ or Miscanthus ‘Zebrinus’ grow to around 4ft overall as well to achieve similar contrasts.
Blue oat grass will grow well in neutral or alkaline soils in full sun. It pays to remove old flower heads and any dead leaves in the spring to tidy the plant up.
Propagation is easiest by lifting and gently dividing clumps in the spring but seed can be saved over winter and sown in containers in a cold frame or greenhouse in the spring.
