problem soil in veggie garden

Hello,
I have had my organic veggie garden for over 15 years. The last few years most crops have been getting different diseases or bugs and end of dieing or not growing much. It has been very frustrating. Do I work on "fixing" the soil by adding nutrients, calcium compost etc or can I remove a layer of soil and "start again" with "good" soil? Will diseases in the soil (like what has been causing my bush beans to rust and die) stay in the soil?
Thanks for any advice.
Marilyn

 

Are you rotating your crops? Disease shouldn't build up if you rotate every year.

 

My question is, are you removing the diseased matter from the garden and putting it in the garbage, or composting it/leaving it in place? If you do the latter, you're probably reinfecting the garden. Most compost piles aren't hot enough to kill viruses or fungi (like rust).

You could also give the soil a boost by planting winter cover crops. You can even do it right now -- West Coast Seeds has broad bean seeds available. You can plant those anytime, although it would have been better to do it just after you cleared the existing crops. Broad beans, like other legumes, fix nitrogen, so other plants can access the nutrient later. Grow them as long as you can in the spring, chop them and till them under three weeks before you plant in a specific area. Leave some to flower and produce beans because they attract aphids, and can keep them away from other plants. The aphids will in turn attract ladybugs to help with the whole garden. Plus the flowers smell exactly like Coppertone, which is kind of disconcerting in a rainy March, but a nice plus. Alternate broad beans with winter rye every other winter to get the most benefit.