Last summer our first organic garden was quite successful. We live in northern Nevada (zone 4 or 5 - I think). We have a small backyard plot. Our garden was invaded by those catapillar worms early on. They did manage to destroy all the spinach and much of the lettuce. I tried a variety of methods to get rid of them, but basically they disappeared in their own sweet time. Is there anything I can do early this season to prepare for them? Is there any way I can make the garden less desirable for them? They were the only pest we really had to deal with, but they ate so much! Even hollyhocks! Any advice is appreciated.

Hmmm. Tent caterpillars? We had quite the population boom up here a couple of years back, they seem to go in cycles just like everything else in Nature. Their "tents" are suspended from branches and are easy (although not pleasant) to control, fire or dunking in soapy/salty water. We also tried spraying the bottom 3' of tent trees with 50/50 water/vegetable oil, that certainly helped. We even placed a couple of ducks inside an enclosed garden (used for heirloom propagation) and that worked out well enough, too.
If your caterpillars are soil-born, much depends on their species.

Best wishes of the season!
John H. Immink
Victoria BC Canada
zone 8b
http://www.ecologicalsgardens.com/

Some things to do to prepare for worms:

Good fall garden clean-up-remove debris, till and plant a cover crop like rye. This will hurt the populations of overwintering pupas in the soil

In the spring consider using row cover to exclude the woths from laying eggs on you veggies which in turn become catapillers.

By a good book on insects such as a Petersen's guide to N. American insects. This way you can look up the bugs and find out if they are good or bad (over 95% are good) and more importantly what they are.

Hand picking the worms daily works well for long term eradication. Bt (bacillus theringensis) is very effective on killing young larva. Encouraging birds into the garden to eat both larva and adults works well (put up a bird feeder and give them safe places to perch and nest). Letting chickens or ducks into free range could mean destruction of the veggies by the poultry. Yes they eat bugs but they also love greens and fruits.

The sudden disappearance of the catapillers just means they either pupated or became adults and will probably be back next year so you are correct to be prepared

Bt and hand picking is the best for caterpillars, but not all caterpillars are bad, so it is a very good idea to get a insect book and identify what "worm" your dealing with. Some are the caterpillar's of butterfly's, which you may really not want to destroy.

A few years back I noticed an old enemy to my garden envading the neighborhood, namely web worms. They stripped the leaves from every shade and fruit tree in the area except my garden. When I saw them comming, I went spider hunting (a favorite pastime in Oklahoma). I placed as many non-posionous species in the garden as I could find. My crops were not touched. When the worms disappeared so did the spiders.

What a great idea!

Another more passive way to get spiders into your garden is to build small piles of rock (about 1/2 high) all around the garden. Spiders love to hide out in the piles and grab bugs.