Sandy soil is especially good for growing root vegetables, including carrots, onions, garlic, turnips, potatoes, radishes and many others. However, if your soil is approaching a 100 percent sand content, you'll want to amend it with compost and other organic materials to give it the nutrients and texture vegetables need. Adding compost to sandy soil also helps drainage--sand does not hold water nearly as well as loamy soils.
Full of vitamin A, carrots can be tricky to grow in anything but sandy soil. But they do like some nutrition, so be sure to dig in any type of compost into your planting area before you begin. Make a shallow furrow with a hoe or trowel, just 3/8 inch deep, and then scatter the tiny carrot seeds into it. Cover it with the soil you dug out, and when your young carrot plants are about 2 inches tall, thin them to stand about 2 inches apart to encourage long, straight roots.
Onions and Garlic
Onions and garlic are essential ingredients in the cuisine of many cultures, including Mexican, Italian, Asian, and even the good old American hamburger. Like other root crops, onions and garlic do best in a sandy soil you have amended with organic matter such as compost, grass clippings and other plant parts. Try planting onion "sets," which look like small onions. They will yield large globe onions, either yellow or red, sooner than if you plant onion seeds. You can plant individual garlic cloves that you buy at the grocery store, but to be sure you are growing a certain variety, such as elephant garlic, purchase garlic bulbs from a seed catalog or online.
If you've never eaten a homegrown turnip, you might change your opinion about this less popular vegetable, especially if you have sandy soil. Plant seeds in early spring in sandy soil into which you have added organic materials such as compost. Make rows 1 to 2 feet apart and then dig a shallow furrow about 1/2 inch deep, into which you scatter your turnip seeds. Thin seedlings to stand 2 to 4 inches apart when young plants are about 4 inches tall. You can eat the greens of the plants you remove--they are very tender when they are young. Pull one or two turnips after about two months to see how large they are--they tend to become woody if you allow them to grow too long, so favor younger turnips for the stewpot.
Radishes are among the fastest vegetables to reward you with a harvest. Within three weeks to one month of planting seeds, you'll be pulling tender young radishes of any type from the ground and impressing your friends and family. Look for seeds of unusual varieties of radishes, such as daikon, cherry belle and white icicle. When you grow radishes in soil that is free of rocks, you'll get more evenly shaped radishes without indentations in their sides.