Spinach is one of the most nourishing cool-weather crops to grow, yielding vitamin-rich, dark green leaves that are excellent for salads and cooking. You can also harvest spinach continuously once its leaves are a good size to encourage new growth.
Since both hot weather and long days trigger spinach to bolt, you should start sowing spinach seeds as soon as possible in spring.
Experienced gardeners will make small, frequent plantings during late spring and summer. This allows them to concentrate on fall as the season for the main spinach crop.
Below are a few tips on growing this nutritious food crop in your backyard.
Spinach thrives in moist, nitrogen-rich soil. Since spinach plants form a deep taproot, you should loosen the soil at least a foot deep before planting.
You can begin sowing spinach seeds as early as six weeks before the last frost or as soon as you can work the soil. If you managed to prepare the soil in autumn, you’ll be able to drop the seeds in the barely thawed ground come spring.
In warm climates, experts suggest planting spinach in the shade of tall crops such as corn or beans. This will spare the young plants the hottest sun.
Caring for Spinach
Do not overcrowd your patch. Overcrowding stunts growth and encourages spinach plants to go to seed. To avoid crowding, thin the seedlings four to six inches apart once they have at least two true leaves.
Fertilize your plot with compost tea or fish emulsion once the plants have sprung four leaves. If you live somewhere with a long, cool spring, you can try successive plantings every 10 days until mid-May.
Since pulling weeds can harm spinach roots, it’s best to spread a light mulch of hay, straw, or grass clippings along the rows to suppress weeds.
Water stress will encourage your plants to bolt, so provide enough water to keep the soil moist but not soggy. Remember to cover the crop with shade cloth if the temperatures become too hot.
Pest and Disease Control
Since spinach is best grown in cool weather, pests are usually not a problem. However, leaf-miner larvae can burrow inside leaves and produce discolored patches.
You can prevent leaf-miner problems by keeping your crop covered with floating row cover, says Good Housekeeping. You should quickly remove and destroy affected leaves to prevent adult flies from multiplying.
Spinach blight, a virus spread by aphids, causes yellow leaves and stunted spinach plants. You can avoid this disease by choosing resistant cultivars.
Downy mildew, which appears as yellow spots on spinach leaves, can also occur during very wet weather. You can reduce the spread of this disease by not working around wet plants.
You can start harvesting from any spinach plant that has a few three-or-four-inch-long leaves. Carefully cut the outside leaves to extend the plants’ productivity, particularly with fall crops.
You should harvest the entire crop at the first sign of bolting. You can do this by using a sharp knife to cut through the main stem just below the soil surface.
An Earlier Harvest
You can continue sowing spinach seeds late into the fall. In warmer climates, you could even harvest spinach well into winter.
If the ground freezes before the plants mature, mulch your plot with hay. Remove the mulch the following spring and the plants should resume growing, allowing you an even earlier harvest!