Periwinkle is quite a common small shrub, appearing frequently in older gardens, especially in rural gardens.

It is a durable, long-living shrub and, though less popular than it was in former times, it is still being propagated by nurseries and sold in garden centres.

It is often sold as a ground-cover shrub and it certainly is very effective in that role, but can be too enthusiastic a spreader.

However, any plant that produces bright blue flowers in spring is worthy of consideration.

Not a shell-fish

The common name of periwinkle is a bit strange, since this is also the name of a small, snail-like sea mollusc that lives close to the seashore and is collected to eat.

Perhaps somebody saw a passing likeness between the rounded shape of the shell-fish and the round outline of the flower, a central hole and a vague similarity between the greyish shell of the sea-snail and the blue of the flowers.

The botanical name of the flower is vinca and perhaps that, in time, changed to winkle. Not that it matters greatly but the link arouses curiosity.

Two species

There are two species of periwinkle grown in gardens.

The greater periwinkle, Vinca major, comes from the western part of the Mediterranean region and the lesser periwinkle, Vinca minor, is native to Europe and southern Russia.

The difference is not huge, but the greater periwinkle is bigger in all its parts than the lesser species.

The leaves of the greater kind can be 9cm long, compared to the 5cm of the lesser sort. However, the lesser form is more widely grown, being neater.

The plants are shrubs because they have woody stems, which are arching and carry opposed pairs of shapely oval leaves.

They are evergreen except in very cold or exposed conditions, where they can lose a portion of the foliage.

Woodland

In their natural range, vinca species are ground-layer plants in open woodland, creeping along, making new roots as they go, much like ivy.

Their spread being indefinite can see vinca forming a large clump that may reach too far.

The excess growth can be rooted out and re-planted elsewhere, and it would seem that it has often in the past been dumped into roadside hedges, where it got going again and survives decades on.

It is not grazed by animals, as it causes stomach upset.

Blue

The flowers are normally a bright violet blue, but variations with pale blue, white and red-purple flowers are seen too.

The flowers appear in sporadic waves, the plant lightly scattered with flowers.

Each flower is flat-topped with a central opening and the flower disc divided in five petal parts.

‘Alba’ is the white-flowered form and ‘Atropurpurea’ has deep red-purple flowers. ‘La Grave’, also called ‘Bowles’ Variety’, has good lavender-blue flowers.

There are also some double-flowered forms, such as ‘Multiplex’, which has double purple flowers. ‘Gertrude Jekyll’ is a compact grower with white double-flowers.

Variegated forms are often seen, both yellow-variegated and white-variegated.

The white form, ‘Argenteovariegata’ is not as garish as the yellow, and both are slower growing than the green-leaved forms.

Space

It is best to plant vinca where it can be allowed to spread, not in flower beds or borders but on banks and awkward corners, even with a good degree of shade, though it flowers less when shaded too much.

The shade of bigger shrubs can be used to hem in the vinca’s spreading tendencies.

If the shrubs are deciduous, the vinca gets some early light to flower and dark evergreen shrubs can set a boundary.

Periwinkle grows in any ordinary soil, even poor ground and a bit dry, but not very dry, and not wet in winter.

Growing leeks

Leeks are a true winter vegetable, standing in the open ground from late summer until late spring the following year, when they flower and eventually go to seed.

They are a useful kitchen vegetable for soups, stews and other dishes.

Leeks are a useful kitchen vegetable for soups, stews and other dishes.

Leeks are a useful kitchen vegetable for soups, stews and other dishes.

Their ability to withstand winter weather is a great bonus, shared only by parsnips and Swiss chard.

Other vegetables, such as turnips and carrots need to be stored if they are not to deteriorate due to weather damage and attacks by pests or diseases.

Leeks are easy to grow, requiring very little effort, and are largely disease and pest-free by comparison with their family colleagues: onions, garlic and shallots.

Sow seeds in April or May for leeks this time next year, and transplant the plants when about 15cm tall, watering well until they are established in their new positions, about 20cm apart. Keep them weed-free at all stages.

Gardening jobs to do this week

Fruit, vegetables and herbs

For really early crops, sow the seeds of early varieties of cabbage, cauliflower, carrots, lettuce and onions now. These will have to be started off in warm conditions indoors, or in a propagator, and grown on in a greenhouse or tunnel. Prune apple and pear trees.

Trees, shrubs and roses

Prune late-summer clematis and buddleja now. Prune off lower branches of garden trees to allow light to reach plants underneath. Control weeds and grass around young trees. The ground may be too wet for planting just now. Roses can be pruned at any time.

Flowers

Slow-developing bedding flowers – such as geraniums and begonia – can be started off in a heated propagator now, but it is still too early for most kinds. If the ground is not too wet, border flowers can be lifted and divided, if necessary, especially if showing early growth.

Lawns

Because soil is wet, a first mowing may not be possible for some time, until the ground is firm and not squelching wet. If the lawn area has drainage, make sure that the drainage outlets are clear to allow surplus water to escape. The lawnmower should be serviced.

Greenhouse and house plants

If they are given some care, Christmas houseplants, such as poinsettia, azalea and cyclamen, can last for several years. They will need watering, but only just enough to keep them just moist. Do not leave pots standing in a saucer of water, or in a chilly draught.

Read more

Gardening: Tree of life

Winter pruning