Starting Out Right
For the healthiest plants, make sure you have good growing conditions. For most vegetables, that means full sun (at least 6 hours of direct sun a day). If you have poor soil, amend it with lots of organic matter, such as compost.
Choose Plants Sensibly
Some plants, such as tomatoes, are naturally more susceptible to pest and disease problems than others. To reduce problems, look for disease-resistant varieties.
Feed Your Plants Naturally
In most soils, fertilizing your vegetables isn’t necessary, but it will help them grow faster and give better crops. If you feed your plants, choose natural products. Well-rotted animal manure from plant-eating critters (rabbits, horses, sheep, chickens) is a great source. Or look for prepackaged organic materials online or at your local garden center.
Note: If you have rich soil already, you may be best off not fertilizing. Too much of a good thing can make your plants put on lots of lush, soft growth that’s loved by pests. Slower growing plants often resist insects and disease better.
If you plant the same vegetables in the same spot every year, disease can build up and be ready before your plants have much of a chance. Keep the element of surprise against your disease foes and try to plant your crops in different parts of the garden each year.
Because many closely related plants are affected by the same diseases, avoid planting them where their relatives were the year or two before. Two of the biggest families are the tomato family (tomatoes, peppers, potatoes, brinjal) and the squash family (squash, pumpkin, cucumber, watermelon).
A layer of mulch over the soil not only helps reduce weeds, but it creates a barrier that can prevent fungal disease spores from splashing up onto plant leaves. In most cases, a layer of mulch 1 to 2 inches thick is best.
For an extra bonus, use a mulch made from an organic material that will decompose (such as cocoa hulls or weed-free straw). As it breaks down, it adds organic matter to the soil for you.
Declare War on Weeds
Weeds not only compete with your plants for water and nutrients, but they may also attract insect pests. And many insects spread disease as they feed from one plant to the next.
Keep It Clean
Many diseases spread rapidly in dead, fallen foliage. Regularly — once a week or more if you have time — walk through your garden and pick up shed foliage.
Also: You can sometimes prevent a disease from spreading through an entire plant just by picking off an infected leaf. Throw dead or diseased leaves in the trash, not in your compost pile.
Wet leaves, especially in the afternoon or evening hours, can attract disease. Avoid watering your plants with a sprinkler. Instead, use a water-saving soaker hose to deliver water directly to the roots.
Give Them Some Air
While jamming plants in is a great way to get the most from your plot, it can also cause problems. Avoid planting your vegetables too close together. Good air-flow between the plants can help prevent many types of fungal diseases.
Plant Some Flowers
A few flowers will not only help your garden look prettier, but they may also attract beneficial bugs. These good guys in the garden attack insect pests such as aphids and tomato hornworms. Don’t worry about these good bugs: Most types are small enough that you’ll hardly notice them in the garden.