What to do in your garden this week

Vegetables
Although winter is a long way off, most winter greens should be planted by the middle of January, although Brussels sprouts generally give better crops if planted before Christmas.

Cabbages, broccoli, kale, cauliflowers and silver beet all need rich ground to give good crops and ground where early potatoes have been grown is generally suitable.

Having been developed from wild seaside plants, members of the cabbage and beet families all benefit from liquid seaweed or compost that has seaweed in it.

If that is not available, a little sea salt (about half a teaspoonful a plant) sprinkled on the ground near the plants can be substituted.

A generous dressing of lime will help prevent club root but, more importantly, avoid growing any members of the cabbage and turnip families in the same spot two years in a row or the risk of this soil-borne fungus increases.

Water seedlings well until they are established and hoe around them to prevent the soil caking.

Use derris dust to kill caterpillars of the white butterfly and diamond-backed moth.

Grey aphis can be controlled by spraying with a solution of soap and water.

Daily picking of courgettes is advised to prevent the fruit maturing.

The bigger members of the Cucurbita family - marrows, pumpkins and cucumbers - should all be forming fruits.

Limit the number by nipping the ends of growing shoots to reflect the plants' capacity and, especially with pumpkins, keep in mind the size the mature fruit will reach when deciding how many to let grow.

Baby varieties, such as Jack-Be-Little or Peek A Boo, will produce six or seven little pumpkins per plant, while Atlantic Giant, which can produce 200kg monsters, should be restricted to one fruit per plant.

Flowers
Roses appreciate a mulch of compost spread around them at this time of year.

The benefits may not be immediately obvious but this feeding will improve the early-autumn display, while a dressing of potash will help keep black spot at bay.

Keep roses watered and be diligent with deadheading, cutting each faded bloom off just above the bud of the next five-fingered leaf.

Prune ramblers as soon as flowering is over, removing old, weak growth.

Gladioli are summer-flowering plants, equally attractive in the vase or garden bed, whether in a mixed colour group or single variety.

The Gladiolus genus has more than 150 species and originates from southern Africa and Europe.

The name comes from the Latin for sword, referring to the leaf shape.

Gladiolus papilio, the goldblotch gladiolus, has hooded flowers in greenish-cream with purple blotches.

A native of South Africa, it has been used widely in hybridising programmes.

Gladiolus nanus - the word nanus means small - is a dwarf group which includes the charming Nymph, a delicate pink with deep pink markings on the lower petals, and pure white The Bride.

A soft pinky orange one with white on the lower petals is referred to in southern New Zealand as The Bridegroom, but the name is not found in growers' catalogues.

Among taller named cultivars, Ebony Beauty is as close to black as one gets; Plum Tart is clear purple; blues include Twilight Dream and Blue Heaven; Fireball and Stromboli are among the best reds; White Contessa is a pure white, large-flowered variety, while Priscilla is a popular warm pink with creamy throat.

These tall forms all need to be staked or tied to a fence.

Gladioli corms should be grown in groups of three to five in well-drained soil.

Plant them about 8cm deep, putting corms on a layer of river sand if drainage is less than perfect.

Keep watered once buds appear or they will not mature.

After flowering, cut off the flowering stem but leave the foliage to grow into autumn so the corm is fed for next season.

In autumn, when the foliage is yellowing, lift gladioli and store corms in paper bags in a cool, dry spot.

When they are completely dry, remove soil and dead foliage.

Each corm will produce a number of offsets.

Save these, plant in a corner of the garden next spring and in two years they will have reached flowering size.

Fruit
Raspberries send up suckers at this time of year.

They often pop up some distance from the main plant and should be cut as far back as possible, taking care not to damage the parent plant.

Check young apple, pear and plum trees put in last winter and cut any overly strong shoots to keep the trees' growth balanced.

Mature trees can have a light pruning to maintain their shape but this is not essential.

Apply pruning paste to every cut, no matter how small, to keep disease at bay.

Double and triple-grafted fruit trees should be checked for even growth on each variety.

If one looks weaker, remove all fruit so that leg puts all its energy into growing a strong stem, not into fruit production.