Planting ornamental grasses

Ornamental grasses should not be planted or moved during autumn, as spring is the best time. Is this true?

- Anne Swithinbank

Q I’ve read that ornamental grasses should not be planted or moved during autumn, as spring is the best time. Is this true, as I’d like to put some in now?

Jill Thurrock, Cheltenham, Gloucestershire

A This is both true and false, as ornamental grasses are divided into two sorts for cultivation purposes. Those known as cool season grasses begin their growth in late winter and produce flowers by midsummer.

Examples include the showy golden oat grass (Stipa gigantea) and shade-tolerant Bowles’ golden grass (Milium effusum) ‘Aureum’. It’s generally thought that they establish better from an autumn planting than a spring one.

As with everything in gardening, advice is tempered by soil and climate. On well-drained soils or in slightly raised beds – and as long as they are planted by mid-autumn – these cool season grasses should take well. Yet on heavy soils like mine, which are often wet and cold during winter, I would delay planting until spring and would not risk lifting and dividing grasses such as festuca past the end of September.