In the garden with Gerry Daly: pale purple beauty

The colchicum, or autumn crocus as it is commonly known, was a bit late this year – it only began flowering in early September. In other years, it has started as early as mid-August, but those years were cold and damp.

This year, the soil remained relatively warm and dry well into September and the autumn crocus was not triggered to flower as early. There are two species generally grown: Colchicum autumnale from central and western Europe, including (very rarely) Ireland, and Colchicum speciosum from Turkey and the Caucasus region.

It is not a true crocus, being related to lilies.

These species are both native to low-alpine meadow and open scrub land where they throw up their flowers without leaves in autumn. In both cases, the summers are dry and warm and the bulbs enter a dormant period in early summer.

The trigger for flowering comes from the presence of moisture and a fall in soil temperatures, signalling to the plant that the cooler, more moist time of year has arrived.

When the flowers have been pollinated, little growth takes place.

The seeds develop in a pod just below the soil. In some of its places of origin, the ground could be covered with winter snow for several months.

The development of the seeds continues until the weather warms up again in spring and the leaves grow out along with a seed pod carried on a flower stalk.

Although these species come from areas of warm summer climate, the winter conditions are much more harsh than they are here.

As a result, the colchicum is completely hardy in all parts of this country.

In spring, the large, broad glossy leaves feed the developing seeds and swell the bulb below ground for the summer rest period.

The leaves are much too big for a plant growing in a climate with a hot dry summer, because they would lose quantities of water that would not be replenished from the dry soil. By early summer, the leaves begin to wither and they will have died away completely by mid-summer.

At the same time, the dry weather is perfect for the final ripening and drying off of the small round black seeds. The pods wither and split open in mid-summer and the seed is shed into the dry soil. This takes place in Irish gardens as it does in warmer places.

The seed is scattered, usually not too far from the parent and when the rainy season comes again, it germinates, getting a few months of dampness to establish a deep root in the soil. Dozens of small grassy plants can often be found near the parent plants. Some of these become fully mature flowering bulbs in three to four years.

Even a few clumps of the large flowers can have a dramatic effect on the garden.

The colour is a clear pink-purple and contrasts very well with the predominantly yellow and orange colours of the end of the year. A lovely double form is called ‘Waterlily’.

The colchicum needs an open sunny position in good, free-draining soil. It is not a woodland bulb and if it is planted in shade, or trees grow out to throw shade over it, it will eventually die out.

It can compete with moderate competition because its large leaves shade out small competition so it can be grown in light grass, but the problem of mowing arises and it is usually planted into the front of a bed or border where the flowers will be most visible.

The bulbs are on sale now in garden centres, sometimes with flowers showing, and should be planted right now.

Tender plants should be either brought under protection or covered outdoors to avoid winter damage. But there is always some leeway on this because tender plants such as begonias, dahlias, cannas, datura and lantana are rarely damaged by the first few frosts of the winter. The damage is really done later in winter when hard frost settles in for a few days at a time.

The tender plants still have their cells full of sugary sap and they are unlikely to freeze while this is the case. In the colder parts of the country, there should now be no further delay in lifting begonias, canna, dahlias and eucomis, and shrubs like fuchsia and lantana. Dahlias and cannas can be risked in mild areas with a top covering of compost or old ashes.

Trees, shrubs and roses

All kinds of pot-grown trees and shrubs can be planted. Check that young trees are securely staked if they need it. Rambler and once-flowering climbing roses can be pruned, if not already done, by taking out the old flowered shoots

Flowers

Take in begonias and dahlias in colder localities. Plant any spring bulbs that were purchased but not planted. If the ground is wet, do not undertake division and re-planting. Many flowers react very badly to being moved into cold wet ground.

Fruit and vegetables

If the soil remains wet and heavy, the land might not dry out until spring so it is best not to trample over it and digging will have to wait. Dig a couple of test holes to see if the site tends to be waterlogged, which does not suit fruit trees.

Lawns

It can be very damaging to the soil structure of a lawn to walk over its surface when it is wet, but there will be occasional spells of dry weather when the ground will firm up enough to carry out a once-off mowing, even in mid-winter.

Greenhouse and house plants

Check over all house plants and greenhouse plants for signs of pests such as mealy bugs, red spider mite and scale insects, which can remain active in a warm atmosphere during winter. There are predators or parasites indoors also.

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