gardening

This pest can affect a whole range of indoor plants and even outside in the warm summer months. Figs, cucumbers, carnations and busy lizzies are just few other likely candidates.

These sap-feeding creatures are found on the underside of leaves and they are extremely difficult to detect, since they are less than 1mm in length. Under magnification they are seen to have eight legs, are hairy and, surprisingly enough, are generally olive green with two dark spots on their backs. It is only the females that turn bright red when they are about to hibernate for the winter in suitable cracks and crevices. In a heated environment they will remain active all year and they can breed at a rapid rate.

Damage to plants is somewhat easier to detect, as leaves become dull and tiny yellow specks appear on the upper surface, causing the foliage to drop prematurely. As infestations increase fine silk webbing starts to cover the plant and, in severe cases, the leaves go yellow then bronze, finally withering and dying.

These mites thrive in a dry atmosphere, so one way to suppress the population is to maintain a high humidity.Try damping down the greenhouse floor daily and regularly mist the plants, especially the undersides of the leaves, with water.

Maintain good hygiene. For example, don't leave dirty pots and canes in a cool greenhouse, as these are ideal hibernating sites, and annually give the glasshouse a thorough clean. Encourage good growing conditions and propagate new plants and, when practical, discarding the old infested ones.

Chemical control is quite difficult, as you need to spray frequently, and they seem to build up a certain degree of resistance to some compounds. Alternating your spraying programme with two different active ingredients can prove more effective. Thankfully, there is another option - using a biological control in the form of a predatory mite, Phytoseiulus permilis. This method of control works particularly well if introduced before infestations are too heavy and you need a minimum of 10C (50F) to ensure sufficient build-up.

timely tasks

l To create a colourful display for just a few pounds sow some hardy annuals in a nice sunny part of the garden. Let the children join in with easy-to-grow plants, like Candytuft, Godetia, and Cornflowers.

l Vegetables sown earlier are likely to need thinning. For the best results thin as soon as the first true leaves appear, and remember to keep the ground well-watered in dry conditions.

l Are your hedging shears nice and sharp? Fast-growing hedges, like privet and leylandii, will now need regular trimming right through the growing season.

houseplant

sword fern or ladder fern (nerphrolepsis exaltata)

This is one of the easier ferns to grow in the home or conservatory, and looks good in a hanging basket or can make a bold display as a single specimen plant placed on a pedestal.

It has superb green arching fronds which can grow up to six feet. Each graceful frond is divided into pinnae and these are arranged alternatively on either side of a midrib. Spores are produced on the underside of these pinnae which can be used for propagation, but this is usually a slow process. They, however, also produce thin furry runners that often creep and root into the compost. From this new plants can develop at their tips, which is a far easier method of propagation.

As to this fern's requirements, it enjoys an acid compost and soft water. Provide good light but out of direct sun, and a steady warmth with a winter minimum of 10C. To encourage healthy growth of the fronds, try applying a high nitrogen fertiliser every two weeks during the peak part of the growing season. Of particular importance are ensuring a high humidity and never allowing your fern to become dry at the roots.

I am sure many of us have suffered yellowing or crispy brown fronds that constantly fall and cause a mess, and the likely culprits are dry air and not enough moisture.

Although the species makes a lovely houseplant, there are some wonderful cultivars that can be grown. For instance, the popular Boston fern, ''Bostoniensis'', with more dropping fronds than the species, and ''Elegantissima'', with attractive feathery fronds. If you prefer wavy fronds, try ''Rooseveltii'', which are dark, and, for a delicate a delicate lacy effect, grow ''Whitmannii'', also called, of course, the lace fern. With such a collection as these I'm sure they would make an excellent talking point.