Question
Last summer while I was away for 2 weeks, my small garden developed a major mold/disease problem especially on tomato and squash plants.  This is the only area available for planting.  Can I prepare the soil so I will not have this again this year?  

Answer
As long as you remove the old plant parts (stems, leaves etc.) and turn the soil you should not have a problem. The fungi spores will be on the old plant parts and could get on the new plants if the old is left in the garden. IF you do see any mold starting spray a fungicide and you will take care of the problem. Until then enjoy your garden.