These kill all insect life, including beneficial predators such as ladybirds, lacewings, and praying mantis, which are the gardener’s friends. 

And who knows what the residual effects of poisons might be.

There are non-poisonous substances that can be used.

These include pyrethrum and rotenone, or derris dust. Both are derived  from plants. But even these will kill beneficial insects.

There are ways to keep insect pests to a minimum.

The first is to have healthy plants. And we do this by ensuring that our garden beds are rich in compost and other organic matter such as manure.

Healthy plants can withstand insect attacks much better than weak ones. It’s survival of the fittest.

If we watch our plants every day we will see the first signs of eggs or caterpillars or aphids and we can wipe them off.

Another way to help protect plants is to grow them alongside other plants with which they are compatible. It’s called companion planting.

Aphids are deterred by nasturtiums, chives, garlic and onions.

So grow these around roses, citrus trees, cabbages, brussels sprouts and other plants prone to aphids.

You can make a non-poisonous spray by boiling rhubarb leaves. Another can be made from garlic.

The cabbage white butterfly will be deterred if you plant tomatoes, tansy, rosemary, sage or nasturtiums around the cabbages.

Places in the garden which are shaded by trees throughout summer need not be bereft of colourful flowers.

Francoa sonchifolia and francoa ramosa thrive in full shade and flower profusely.

The first has pink flowers and the second tall white flower spikes.

Other shade lovers include clivea miniata, astilbe, chinensis pumila, hellebores or winter roses, bergenia, hosta, polygonatum, Japanese anemone, eucomis and pulmonaria.

Carrots sown now will take off and in a couple of months will give you edible thinnings.

It’s a lot too early for tomatoes, sweetcorn, pumpkins, climbing beans, capsicums, eggplants and cucumbers. 

Wait until the ground has warmed up well, in late October or early November and they will forge ahead. 

Of course tomatoes can be started now in a glasshouse or on a windowsill.

in the months ahead there will be times when we must water our gardens and many depend on tank water.

These people can make life easier by choosing plants that are drought-resistant and by improving the soil’s ability to retain the water it does receive.

Sandy seaside soils have poor water-retaining qualities but these can be dramatically improved by adding plenty of organic matter such as compost. Heavy, continuous mulching with hay or leaves or seaweed will gradually build up a deep soil rich in humus. 

Mulch not only helps soil retain moisture but keeps the soil temperature more even.

In very dry periods sprinkling plants with compost water is very beneficial.

Fill a bucket half with well-rotted compost and half with water. Stir several times and pour into a watering can.

Annual drought-resistant flowers include phlox, cape marigolds, cornflowers, ice plant, morning glory, scarlet sage, four o’clock and dwarf convulvulus.

Shrubs that stand dry conditions include barbery, juniper, rugosa rose, rose acacia, Saint John’s wort, grevillea rosemarinifolia,  acacia ligulata and hakea costata.

Perennials include gypsophila, aquilegia, iceland poppy, michaelmas daisy, red hot poker, snow-in-summer and ground ivy.