Spinach is one of the most satisfying cool-weather crops to grow, producing large yields of vitamin-rich, dark green leaves that are excellent for salads and for cooking. Since both hot weather and long days trigger spinach to bolt (send up a seed stalk) quickly, the secret to success with this crop is to start sowing seeds as soon as possible in spring; to make small, frequent plantings during late spring and summer; and to concentrate on fall as the season for the main crop. In areas with a long, cool spring, make successive plantings every 10 days until mid-May. In warm climates, plant spinach in the shade of tall crops such as corn or beans. The young plants will be spared the hottest sun and be ready for harvest in fall or winter. Choose savoyed and semi-savoyed varieties to plant in the fall. Savoyed varieties are characterized by their dark green crinkly leaves. They are best for planting in the fall because they become especially crisp in cold weather. Choose smooth-leafed spinach for a faster growing time. Smooth-leafed spinach grows upright and produces leaves lighter in color than those produced by savoy spinach. It grows quickly and easily and is the perfect addition to any summer salad. Though spinach prefers a mild climate and will not do well in extremely hot temperatures, it does like full sun. Spinach will produce in partial shade, though the yield may not be as impressive, nor the plants as productive. Spinach likes a moderately moist habitat, but will not do well in soil that floods regularly or does not drain well. Spinach prefers a slightly acidic soil with a pH between 6.5 and 7.0. You can add limestone to the soil to adjust the pH level manually. Sow seeds 0,5 inch (1 cm) deep and two inches (5 cm) apart. Make sure the rows are spaced at least eight inches (20 cm) apart if planting in rows. Doing so allows the seeds to mature without having to compete for space. If you are transplanting seedlings, space spinach plants about 12 to 18 inches (30 – 45 cm) apart. This allows the seedlings to grow and expand their roots without competing with each other for space. Cover the seeds with soil and pat lightly. The soil does not need to be compacted over the seeds; in fact it should be rather light and fluffy. Just be sure that the seeds are not exposed to the air and are entirely covered by soil. Water the planting area thoroughly. Make sure to use a watering can or a light shower setting on your hose. Adapt to hot weather. If you live in a particularly hot climate, consider using cold frames or heavy row covers to keep the soil cool during hot summer days. As your spinach plants grow into seedlings, thin them lightly to prevent the plants from competing for space. You want the plants to be spaced far enough apart that the leaves of neighboring plants barely touch, if at all. You want the spinach to grow in soil that is continually moist but not overly drenched. Spinach is a cold-hardy crop that farmers often maintain over the winter for an early crop next year. During winter, protect your spinach plants in a “low tunnel” of row cover over a simple PVC frame, with ventilation to prevent overheating on sunny days. The spinach plants will be semi-dormant during the darker months, requiring infrequent watering and no fertilization. Once longer daylight hours trigger growth in late winter, provide water-soluble fertilizer and care for the growing spinach as you would at other times of year.