The Gardeners Almanac

Overview:

Crocus C.vernus is the parent of many of the dutch crocus found flowering in UK gardens in spring.

They originate from various mountainous regions of Europe.

Crocus come in many colours and the familiar wine glass-shaped flowers and grass like leaves bloom early to welcome in the spring.

They are suitable for the border, rockeries, growing in containers, or for naturalising.

They generally grow to around 100-150mm (4"-6") high and flower from late February and through March.

As the flowers die back do not remove the flowers, and do not tie the leaves into bunches or cut them before they are dead.

Once the leaves have turned yellow they can be pulled off.

For naturalised plants, delay mowing the lawn until the tops have died back.

A Collection of Crocus in various situations

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Cultivation:

Week 16:

Every two or three years lift and divide clumps as soon as the leaves are turning brown.

Remove leaves, dead roots, skins and old corms, grade the corms into two or three sizes, plant the largest ones immediately.

The corms should be planted 50mm-75mm deep in heavy soil or 150mm deep in light soil, in both cases space the corms 75mm-100mm apart.

It heavy soils put some sharp sand under the corms if drainage is questionable.

To increase future stock select and dry the smaller offsets in shallow trays in a warm greenhouse for a few days.

When dried, plant out 50mm (2") deep and 25mm (1") apart in a nursery bed where they should remain for a couple of years to reach flowering size.

Week 16:

Collect seed capsules when they begin to split open and sow the seeds in trays / pots of seed compost.

Lightly cover the seed with compost then place in a coldframe to germinate.

Allow the seedlings to grow on undisturbed for two years, then plant them out in their flowering positions.

Seedlings can take up to four years to flower, and don't usually come true to type.

Week 35>:

Crocus should be planted as soon as they are available.

Set the corms in groups, in almost any soil, provided it is well drained, and ideally, they are protected from cold winds.

The corms should be planted 50mm-75mm deep in heavy soil or 150mm deep in light soil, in both cases space the corms 75mm-100mm apart.

It heavy soils put some sharp sand under the corms if drainage is questionable.

Week 40:

For indoor culture, plant six or seven corms in a 150mm (6") pot of a proprietary bulb fibre that should be moistened thoroughly prior to planting.

The corms should be planted with tips just showing above the level of the fibre.

Leave in a cool, dark, well ventilated place such as a cool greenhouse or coldframe at a temperature of 9-1O°C (45-50°F) and water at intervals to keep fibre moist.

When the stems are 50-75mm (2-3") high and the buds are beginning to appear, bring them into a cool room to bloom.