Before planting your spinach seeds, make sure your soil is fertile. The dark green color of spinach leaves is due to adequate nitrogen content. Before planting your seeds, apply a general garden fertilizer, a 10-10-10 product, at a rate of two to three pounds per 100 square feet. Use the recommended amount of fertilizer based on your soil test report. Apply the fertilizer in three inch bands under the row of spinach plants. Then, every 30 days after the plants emerge, fertilize again to keep the soil moist.
Once the spinach plant has produced two-thirds of its mature seeds, harvest it. The leaves are best when young, tender leaves are used in salads, while older leaves are best for soups and stir-fries. Spinach is a good choice for planting in spring, when the weather is warm and the soil is well-ventilated. Harvesting the leaves of the spinach plant can begin as soon as five weeks after sowing. Harvesting the entire plant is also possible, though it is not necessary to harvest all the leaves of the plant.
If you do not want to wait until spring to grow spinach, you can start your seeds indoors. Alternatively, you can purchase seedlings from nurseries. Spinach seeds are best planted at 60 to 68 degrees F, so it is recommended to sow them indoors during the cooler months. A seed-starting mat will help raise the soil temperature. It will germinate much faster in this temperature range. A few days of priming will make a big difference in the germination time.
You can also plant spinach seeds directly in the garden six weeks before the last frost. Afterward, you can start cultivating the soil and planting the seeds in the ground that has just barely thawed. If the spring is long and cool, you may need to repeat the planting every 10 days until mid-May. Once the soil is sufficiently thawed, your spinach plants will begin to sprout. Then, they'll produce leaves.
When you're ready to plant, simply remove the stalks from the seedlings and store them in a container under the plants. The seeds will remain viable for at least six years. After harvest, discard the stalks and plant your new spinach seeds. After planting, rotate your crops so that the plants keep producing green leaves. After all, they'll be good for two more years. This way, you'll have an abundant supply of spinach over several weeks.
As a cool-season crop, spinach is easy to grow. Start planting your spinach seeds four to six weeks before the last spring frost. In central Ohio, the "frost-free" date is around mid-May. The seeds will not bolt unless they reach 30 cm in height. If you're growing spinach in an area where the climate is too warm, plant them in the fall. The last thing you'll need is a spinach plant that's too big to handle.
As with any vegetable, you'll need good soil to grow spinach. Make sure your soil is moist, cool, and drained regularly. You can also use a nitrogen fertilizer as a side-dress. Some varieties are mildew-resistant. If you're growing spinach in a garden, you can use an organic spray called Burpee's K+Neem. If you're concerned about pests, talk to your Cooperative Extension Agent and ask for recommendations.
If you're planning to grow spinach for the first time, it's best to buy some seedlings from the store. You can thin them out later when they're large enough. You can also prune your spinach plants to encourage new growth. Another popular spinach substitute is African spinach, Amaranthus gangeticus. If you don't want to buy seeds, you can use other types of spinach such as water spinach or Malabar spinach.
If you're planning on growing spinach as a crop in your garden, remember to thin the plants regularly. You want to prevent weeds from taking up too much water and nutrients from your plants. Once the leaves are 6 to 8 inches long, you can harvest them. In hot weather, you can harvest them at their crown, or clip them at the tips. When planting chard and kale, keep in mind that Malabar spinach has short stems. If you're growing spinach as a spring green, harvest the lower leaves when they grow three to four inches tall. Then you can harvest Malabar spinach, as well as dandelion. If they're left to grow for too long, they develop a strong flavor.