Consult the Resource section at the end of this bulletin for some of our favorites. Good Plant Care Insects and diseases usually attack unhealthy plants, so the first step in preventive control is to make sure your plants are rooted in healthy soil, are getting the right amount of water, and are not competing with masses of weeds for water and nutrients. Incorporate organic matter into your soil every year to improve the water-holding capacity and soil structure, and to provide slow release nutrients. Spend a few minutes pulling weeds every time you visit your garden, rather than letting the weeds get so big that it's a major chore to get rid of them. If you're one of those people who can't bear to thin seedlings, you could be sacrificing your plants' health.
Overcrowded plants are less vigorous because they have to compete for water and nutrients.
And they are more susceptible to damage from insects and disease. So do your plants a favor and thin according to recommendations on your seed packets. You'll reap a bigger harvest in the long run. Up Leaving old squash vines, tomato plants, and other debris in the garden after the season ends is like putting a welcome mat out for insect pests. Many insects overwinter in such debris, and then get an early start nibbling on your plants the next year.