Plants which are looking good this month

Papaver Patty's Plum will be in bloom in May and June. For sun with fair drainage.

A big single flowering species shrub rose and one of the first to show colour, Rosa cantabrigensis will be at its best this month.

Obviously not flowering at the moment but this is a very good time to establish Buddleja. Shown is Blue Horizon.

Astilbes are now well into growth and can be planted now to flower this year. This is the compact form Mount Etna. All prefer moist soils and full or or part shade.

We have a number of cultivars of masterworts. This is Astrantia Claret, one of several red clones. Good for woodland edge situations with attractive bright green semi glossy leaf and honey scented flowers at about 60cm tall.

Originating from Nepal at 2800m we called this a Cephalaria for many years but have been put right by the RHS botanists. Dipsacus inermis is a teasel relative and a superb structure plant for see through plantings. Flowers late summer and autumn and the dead stems look great until cut down in early spring. Good bee and butterfly plant.

Geranium Brookside must be one of the best blues. A longer flowering period than Johnson's Blue and, we think a better plant altogether.

You've still got time to slip in some heleniums for late summer colour. This is Helenium Rubinzwerg, a very good short red form which blooms August-September at only 80cm tall

Pittisporum are dependable large shrubs, this is our own selection "Holbrook". They provide useful structure in the winter garden and tropical evening scents from the flowers on warm spring nights.

Big fat and dumpy spikes to 2 metres in late summer, this is the delicious Kniphofia rooperi.