You can go mad reading all the advice written on what to do or not to do about bugs in your garden, so just to add to it I thought I would share a few of my pest control hints for the vegie patch - probably more gardening philosophy - part science, part permaculture, part personal experience.
Accept that there will always be bugs. Having a few bugs on plants is much better than insecticides and poisons. In a healthy garden there will be lots of good bugs too and they will help keep the “bad” ones in check. When conditions are right for them, any bug will make the the most of it. They aren’t really bad. They just like to eat the same plants we do.
Encourage the good bugs. Planting your favourite insect attracters adds beauty to the vegetable garden area as well as attracting beneficial insects. I don’t follow strict companion planting, rather I plant a few of my favourite little flowering plants – ones that will not compete too much with the productive plants. A number of flowering herbs are great for this purpose as well. (Pineapple sage and Thai basil are always in flower.) Oh, and if there are spiders hanging around, be grateful. You know what they like to eat..
Take care of the soil. Better soil makes your vegetables less susceptible to insect pests and diseases. Happy plants don't get sick and don't attract as many pests. Preparing the soil well (digging in decomposed manure, compost plus some potash and blood and bone) gives your vegetable a good start in life.
Bugs love our Queensland Summers. In summer, I only grow vegetables that like heat. Most vegetables just don't like too much heat. Most varieties of tomato can't stand humidity. If it's too hot or too humid for them, plants stress and attract bugs, just like people seem to get the flu when they are stressed and run down. In our part of Queensland, from Easter onwards the weather is generally finer and milder, so that’s when I like to plant most vegetables.
Remember which plants do well for you (and when). Eggplants, capsicum and chillies love the heat. You won't find an eggplant troubled by bugs just because it gets hot. During our humid summer zucchinis and squash have problems with mildew and are just not worth the effort, but in our drier cooler winters they are usually trouble-free. Hearting lettuce varieties, like Iceberg, are a lost cause here even in winter. I don't bother with them and only grow the open leafed kind.
Mix it up. Don’t grow too much of anything. Large quantities of their favourite food seem to attract bugs. They set up home and breed. My beds may not look as neat as those with long straight symmetrical rows but I don’t think the plants can tell the difference. Planting herbs and flowers amongst the vegies, as well, seems to confuse the bugs so it’s hard for them to find a decent meal .
Besides - I’m only growing for my family’s needs so I don’t need more than a small amount of anything but I love having lots of variety.
Full sun is not always best. If you live in Queensland, forget what gardening books from southern states preach about full sun and growing requirements. In Summer once it gets hot make sure there will be something shading the more sensitive plants, especially from midday on. They can get scorched or even stew in the heat and bugs love steamed vegies.
Look after your friends. Birds, lizards frogs and spiders are great hunters. They need shelter and some water and they’ll feast on your bugs. Not only does mulch keep the moisture in the soil and stop weeds but it can also shelter ground dwelling friends (beetles, spiders, lizards) who will help look after your plants.
Give your vegetables a combination of good soil, regular moisture and conditions they need, and plant at the right time of year for your climate, and bugs will not be a major a problem. I never spray my vegies, not even with natural or organic bug sprays.
Be prepared to lose a few. Obviously my methods are not always successful. Sometimes the bugs win. If there are just a few holes in leaves, I live with it. If it’s more than that, I will try removing the effected parts first and/or removing the bugs but if it’s badly infested, rather than stress or spray I will remove the plant and feed it to the chooks. (Lose a battle to win the war)
So (for what it's worth) that's my philosophy for dealing with pests. I'm sure there are other methods that more serious vegie growers use. I would love to hear what works for you.