Days to germination: 7 to 12 days
Days to harvest: 45 to 50 days
Light requirements: Full sun, or partial shade
Water requirements: Regular watering
Soil: Rich and well-drained, with extra lime
Container: Yes, any variety
Kids love to hate it, but spinach is a very healthy and quite tasty green that can grow well in the home garden. The hard part is getting your crops timed to avoid the hot weather. Spinach has no tolerance at all for heat and will go to seed (“bolt”) as soon as it gets hot.
Some spinach varieties have smooth leaves and some are deeply wrinkled (also known as savoy spinaches). Ones in-between are usually called “semi-savoy”.
There is a good reason why Popeye liked his spinach. It’s an extremely nutritious green. It has calcium, iron, vitamins C and K, folic acid and lots of fiber. You can eat it raw in a salad, or cooked with a meal.
Starting from Seed
Spinach is not a plant that you should start indoors as it does not survive transplanting well. Plan on seeding directly out into the garden. Dig your soil to loosen up, and add organic matter like compost and some lime.
It’s an early, cool weather crop so you can put your seeds out about 5 weeks before you are due to get the last night-time frost in your area.
For spacing of your seeds, plant them around 12 inches apart. Plant several seeds in each intended location because spinach seeds are notorious for not sprouting. If more than one seedling comes up, thin it out to leave the strongest one. Your seeds should only be put in about an inch deep in the soil.
Like other cool weather garden vegetables, you can get a second harvest if you plant more seed later after the hot part of summer. A definite option for spinach. Plant another crop of seed about 45 days before you expect the first frost in the winter. If your summers are short, it might still be too warm for the plants to do well at that time though.
Even though spinach is planted quite early to begin with, you can even get a further jump on the season if you put your seeds in the garden the winter before. Plant some seeds before the frost sets in for the winter, planting about 2 inches deep to protect them. Make sure to mark the area so you know where you’ve planted them, and you’ll probably have early spring sprouts of spinach the next year.
Spinach is a very heavy-feeding plant, so use a nitrogen-rich fertilizer about a month after planting to help keep your plants healthy and producing.
You should be consistent with your watering and not let the plants dry out too much. They may need water 2 or 3 times a week if the rainfall isn’t enough.
If you live in a climate that has mild winters (above freezing), you may even be able to grow spinach right through the winter. Try planting it in a sheltered location if you are going to keep your plants alive over the winter. They are very cold-tolerant and may provide you with fresh salad greens right until next spring.
Spinach grows well in containers, and is well-suited for balcony gardening. If you plant your spinach in containers small enough to comfortably move when full, you can probably prolong your harvest period by keeping the plants out of the heat of the sun. Move the pots into partial shade in the afternoons to help keep the plants from bolting in the heat.
Just like in the garden, add compost to the soil and fertilize regularly with a high-nitrogen fertilizer. Container plants can dry out quickly, so keep a close eye on your spinach so it doesn’t try out. Too dry conditions can cause the plants to bolt.
Pests and Diseases
Your biggest problem with growing spinach is actually the temperature, more than any other pest. Shade your plants when you’re expecting hot weather, and keep your plants well-watered.
Besides the summer weather, you will also need to watch for downy mildew that can create fuzzy mold on your spinach leaves. Don’t let the leaves of your plants stay wet any longer than necessary, and when you water them, target the soil around their roots, not the entire plant. Water spinach early in the day so any damp leaves can dry off before nightfall. You can buy mildew resistant varieties of spinach.
The leaves are open to damage from several leaf-eating insects from slugs and snails to leaf miners and even cabbage loopers. There are various controls and treatments for each type of insect, though manually picking off slugs and worms works very well. A little slug bait or a saucer of beer can help keep the slugs away from your crops too. Using a fine net over your plants will keep away the flies that lay the leaf miner eggs, and can add a little helpful shade at the same time.
Harvest and Storage
You can usually start to harvest spinach once each plant has a few full-sized leaves, if you intend to just harvest a leaf or two at a time. The plant will just keep growing new leaves. For a larger harvest at once, you can wait until the plants are more fully grown and cut the entire plant off. It may regrow some leaves, but the plant is basically finished if you harvest it this way.
The exact times for harvesting aren’t that important because you can eat even very young spinach leaves. In fact, the young leaves are usually the tastiest and most tender.
When the weather warms up and the days get significantly longer, the plants will bolt and grow a tall stalk up through the middle of the plant. Your crop is over at this point. By the time you realize the bolting has started, the leaves will be bitter. Some varieties of spinach are more heat-hardy, so choose ones that will suit your climate. Tyee is a good one for warmer weather.
Go out to pick spinach right before you intend to use it, to keep the fresh flavor. Wash the leaves well, especially if you’ve cut the entire head. Insects hide between the leaves, so give your spinach a good shake before bringing it in the house.
Spinach doesn’t store all that well and should be used fresh. You can freeze it, but it won’t be suitable for raw use after that, just cooked dishes. Blanch the leaves for about 2 minutes in boiling water, then let cool. Dry off the leaves and freeze them either whole or chopped.