THE flower garden is now coming towards its peak of colour and interest, so for most gardeners thoughts of bulb planting would be considered premature. However, if you are thinking of injecting a little late colour into beds and borders, then autumn flowering bulbs must be considered during the next two or three weeks.

These neglected gems are available for a very short period during July and early August. They must be planted immediately, for they do not remain dormant for long, some of the livelier varieties being in full flower during early September.

Of all the autumn flowering bulbs it is the colchicums, or naked ladies, which create the greatest impact in the home garden. With their bold chalices of brightly coloured blossoms pushing up leafless from the rich brown soil it is easy to see how, over the years, they obtained their common name.

Not to be confused with the smaller and more elegant autumn crocus, the colchicums in their lilac, pink and creamy white shades are altogether more resistant to the vagaries of autumn weather and unlike many of the true crocus do not seed themselves freely.

The only disadvantage with these very beautiful plants is the dominance of their glossy green foliage when it appears during early spring. While the blossoms of colchicums are welcomed virtually anywhere, planting needs to be carefully arranged so that the bulky leaves are not a nuisance.

The true autumn crocus are a different story. These can be planted in exactly the same way as their spring flowering counterparts.

They naturalise well amongst grass where they often seed themselves freely, but they are of the greatest value when scattered amongst established shrubs.

A carpet of lilac or white beneath shrubs that are tiring of their late summer efforts at flowering is extremely welcome, and if carefully arranged need not interfere with any routine maintenance.

Sternbergia is rather like a yellow crocus, but not as easy going. It is a waste of time trying to naturalise it in grass and it will certainly not tolerate the rough and tumble of border life. A sunny rock garden pocket is perfect, or if you are an enthusiast, then a deep pot in the alpine house.

WHAT'S NEW

Mystery Fire is a dwarf evergreen berberis with bright orange-yellow flowers during late spring.

Indian Summer is an apricot coloured campsis or trumpet vine.

Lady Katsuko is a red and white flowered picotee hydrangea.

Q The leaves of my holly tree are riddled with unsightly tunnels. Can you tell me the cause and how to cure it?

A The tunnels which appear between the upper and lower leaf layers are caused by the leaf miner grub. This can best be controlled by regularly spraying with a systemic insecticide.

Q I want to grow Siberian wallflowers. When should I sow the seeds?

A Siberian wallflowers should ideally have been sown last month, but there is still time. Sow directly into the open ground and transplant the seedlings when large enough to handle.

Q My hollyhock plants have got rust disease and all the leaves are falling off. Is there anything I can do to save them?

A Not really. Hollyhock rust is a devastating disease which is difficult to control by spraying. It is best to dig them up, collect any leaf debris and burn it. In future only grow strains of hollyhock which are rust resistant. Most modern varieties do have a high degree of resistance to the disease.