Q. Sandy soil is difficult to keep ridged. The ridges melt away in heavy rains that we have here. What can I do to improve the soil, so it will hold up, and how can I build the ridges strong enough that they hold up?
A. Gardening in sandy soil has its challenges, but they are not difficult to solve. For very sandy soil I recommend you find clean organic material, such as grass clippings or leaves – mulch the leaves as fine as possible with a chipper/shredder or mulching mower – and then till them into your soil-beds. In the fall you should be able to find an abundance of leaves. Just don’t use walnut leaves, as the sap is very hard on some of your vegetables, especially tomatoes. This will improve your soil tilth, and over time it will help the deterioration of the ridge sides.
Also on sandy soil – to reduce the tendency for the sides to give way, I make the ridges a bit higher than normal – perhaps 5 to 6” – by pulling more soil from the planting area. This usually leaves the planting area only a little bit higher than the aisles. Then I will do one of two things. As I make the beds, the final step is to hit the inside base of the ridges for the entire length a couple of times with the rake. This firms and settles the soil in the ridges, making them just a bit lower, wider, and less likely to fall back onto the newly sprouting seedlings. For the most sandy soil I will go down the sides of the beds and press the ridges down with both hands cupped, to help them retain their shape.