Sow seeds 1/2 inches deep directly in containers or a seed tray. Seedlings will germinate in 5-14 days depending on the variety and growing conditions. If you have sown seeds in a seed tray wait until 2-3 true leaves appear on each plant and then transplant them into the original pots carefully.
For growing spinach in pots, choose a pot that is least 6-8 inches deep. You don’t need a very deep pot rather use a wide pot. You can either use so many small pots and grow one plant in each or select large window boxes, wooden boxes or crates.
Provide each spinach plant a space of 3 inches, if you want to pick large leaves, give more space to each plant, 5 inches. If you want to harvest leaves at very young age, then the spacing can be reduced to 2 inches only. Divide the planter box into squares, and see how many plants will feel comfortable in it.
If you are growing spinach in fall (autumn), keep the plant in a sunny spot (in mild climates) due to shorter days and less intensity of the sun. For spring and summer planting keep your potted plants in a location where it receives some shade, especially in the afternoon. In subtropical or tropical climate, place the containers in a spot that receives plenty of shade.
For growing spinach in containers, use quality potting mix rich in organic matter. The texture of soil must be crumbly and loamy. Avoid soil that clogs the drainage and remains waterlogged. Well-draining soil is most important factor for the optimum growth of spinach in containers. Soil pH must be neutral.
When growing spinach in containers, avoid water stagnation because it will lead to the development of rot and various fungal diseases. Also, avoid wetting the foliage. Keep the soil moist but not soggy or wet. Taking care of good drainage in the pot is necessary.
Spinach seeds germinate in temperatures as low as 40 F (4 C) and in high temperatures too. The best soil temperature for growing spinach falls in the range of 50-80 F (10-27 C). Many spinach cultivars can tolerate temperature down to 20 F (-6) and up to 90 F (32 C) easily. Once the temperature starts to soar high, you may need to provide shade to your plants.
Growing spinach indoors on a windowsill is a great idea (as it doesn’t require a lot of sunlight) if you’re short of outdoor space. For this, buy a few 6 inches deep small pots and grow spinach in them. You can also grow herbs and annual flowers there.
Also Read: How to Make a Windowsill Herb Garden
Growing spinach in pots doesn’t need special care. Regular watering, fertilizing and the right soil is the key to the great harvest.
For growing healthy green spinach, you have to provide nitrogen. At the time of planting, you can mix time-based fertilizer, or you can add a lot of compost or well-rotted manure, this will provide nutrients slowly. Feeding the plant with fish emulsion, compost or manure tea in the middle of the growth and so on is a nice organic way to promote the plants. If you have not done added time-based fertilizer, you can also feed the plant with balanced liquid fertilizer at regular intervals.
Do mulching, even if you’re growing spinach in pots. Mulching plants with organic matter will help in retaining moisture.
You don’t need to worry much about pests as you’re growing spinach in containers, in a small space and you can easily control them. However, keeping an eye on leaf-eating insects like slugs and caterpillars and other common garden pests like aphids will help you in eliminating them in time.
It is a cool season crop, but growing spinach in tropics and subtropics is extremely easy. Moreover, you can grow it successively as a bi-annual crop, except in hot summer months. You’ll need to provide it shade and enough water to keep the soil temperature cool and moist.
In warm weather, vegetables like lettuce and spinach begin to bolt early and start to set seeds. One of the most important things you need to consider when growing spinach in tropics is to grow heat tolerant varieties (there are a lot of Asian varieties that are suitable for tropical climate) that grow slowly and do not bolt quickly. These varieties easily tolerate the heat and humidity.
The spinach plant will be ready for harvest 37-50 days after germination depending on the growing conditions and cultivar.
Harvesting can be done when the plant has formed at least 5-6 healthy leaves, and they are at least 3-4 inches long. Pick outer leaves first and leave the new inner leaves so that they continue to grow or cut the whole plant off at the base with a knife or scissor, the plant will resprout again.
When the weather becomes humid and hot (in warm climates) the plant tends to form an erect stem, on which you can see some small yellow or green flowers developing. To coincide with the flowering and the subsequent production of flowers, the foliage of the plant thickens and changes in flavor (more bitter), which is called bolting, so it is convenient to harvest the plant before it starts flowering for better taste.