As individuals, the Teasel, the showy Vatican sage and the Opium poppy do not live very long, but they are such prolific self-seeders, that every year they leave behind hundreds of offspring.

Each can be used alone in herbaceous or mixed borders, singly or in small groups, but they look extremely effective when allowed to intermingle together in large numbers. They all have a fairly upright habit of growth and when combined create a shimmering interplay of repeated forms, flower heads and seed capsules.

The Teasel, Dipsacus fullonum, is a prickly, British native with a towering, central spike, anything from 5ft to 7ft high at flowering time in August. Spiny leaves appear in pairs along the length of the stem, clasping it in such a way as to form reservoirs that collect rain and dew (hence one of its common names, Venus' basin).

The Teasel's heads are thistle-like cones (once used to "tease' cloth), surrounded by a ruff of narrow, spiny bracts and covered in tiny, mauve flowers. These have the peculiar habit of opening first in a ring around the centre and then moving in a wave motion towards the top and bottom of the flower head at the same time.

The Vatican or Clary sage, Salvia sclarea var. turkestanica, is a big, smelly plant, not as tall as the Teasel, but wider, with broad, wrinkled leaves covered in gland-tipped hairs. To me, its perfume is all sunshine and citrus - others will tell you it smells of cats. It produces a candelabra of flower spikes in a cloud of hooded, lilac and white flowers for many weeks.

The Opium poppy, Papaver somniferum, is as valuable for it seed heads as its flowers. It grows annually from seeds of the previous summer, 3ft to 4ft in height with glaucous, lobed leaves. The tissue-paper blooms can be any colour from pure white to reddish purple and when the petals fall they reveal flat-topped pods covered in a pale bloom.

All parts of the Poppy contain latex, but it is from the ripening seed- heads that opium is extracted. In this country, they yield little of the drug, but enough for home-made Poppy-tea remedies for the relief of rheumatic pain and to induce sleep in children! Don't try this at home.

John the Gardener