Which are the first and the last vegetables harvested from the garden? The "lowly" root crops.

Root crops are an eclectic mix of different plants from many different genera. Some grow quickly and produce a crop in just a few weeks. Others take the entire season.

Because they take little space, they are ideal for small gardens. And since they have no definite maturity stage to make them edible, they are ideal for short-season garden areas.

The roots are the plants' storage organs. These underground fleshy stems are where the plants store excess food to help them reproduce or to sustain them in subsequent years. (Some plants, such as potatoes, aren't true roots because they have buds that will grow new plants.)

Most root crops are hardy or semihardy vegetables — so the above-ground portions tolerate light freezes. That means you can safely plant most of them right now if you live along the Wasatch Front. (Wait a few weeks if you live in a colder valley location.)

Most of these crops do best when planted earlier in the season. Since the root is a storage organ that expands to store the food manufactured in the plant top, the faster the top grows, the bigger the root gets.

Warm, bright days and cool nights maximize root expansion and bright colors. High temperatures, particularly at night, make the plants respire faster, burning more food. That burns off the sugars used to enlarge the roots and to form bright colors.

Soil is important when growing root crops. Most prefer deep, rich, organic soil or sandy soil with added organic matter.

At times, root crops will form forked roots. Rocky or heavy soils and fresh manure can contribute to this problem, so screen rocky soils and only add well-rotted compost to your beds. Root crops grow best with a balanced nitrogen and phosphorous fertilizer. Excess nitrogen fertilization stimulates top growth at the expense of root growth.

Planting crops too close together can result in plants that have small or no roots at all. As the seedlings emerge, it is critical to thin them to the desired spacing. A root harvested at a 2-inch diameter means plants should be thinned to 2 inches.

Following is a selected list of root crops that grow well in Utah. The numbers in parentheses are the days from planting until harvest for that variety.

Beets: Cylindra (60); Detroit Dark Red (63); Golden Beet (Yellow) (55). Harvest beets at 2 inches in diameter, although they will grow much larger if left all season. While large beets are tougher, they also are sweeter and store better.