True confessions… I am allergic to spinach. Very sad, I know. So, I don’t grow it. Everything I’m about to tell you about spinach cultivation I learned from such wise gardeners as David Whiting, Colorado State University professor and State Coordinator for the Colorado Master Gardener Program, and Diane E. Bilderback, one of my favorite garden writers (and, along with Dorothy Hinshaw Patent, author of my favorite veggie gardening book, Garden Secrets).
The first tricky thing about spinach is when to plant it. Being extremely day-length sensitive, it is sure to bolt when it receives 14 or more hour of daylight per day. You can squeeze in a crop as soon as the weather is warm enough (and thankfully, spinach is relatively hardy), or wait until days are getting shorter again and plant for a fall harvest.
Because spinach is able to handle a hard frost, it’s a good choice for gardeners wanting to overwinter greens in a coldframe or greenhouse. In this case, start the seedlings in mid-to-late summer, as not much growth occurs while temperatures are very cold. The plants can be held in a state of near-dormancy until the weather warms again. This over-wintered crop will bolt at the slightest suggestion of spring, so for continual harvest, be sure to seed a new crop as soon as soil temperatures reach 50°F. (This is the optimal temperature for germinating spinach seeds.)
Spinach does well in rich soil; lots of nitrogen means lots of leaves. Water regularly and mulch to keep soil evenly moist. Full sun is best, but since spinach can tolerate more shade than fruiting crops, it’s a good choice if you have a marginally sunny spot.
Spinach can also tolerate relatively high salt concentrations. Salt buildup (usually from the use of from commercially produced dehydrated manures) is a big problem in Colorado—we don’t get enough rainfall to leach salts beyond the root zone. While the only cure for too-salty soil is water and more water, spinach is a crop to try in the meantime.
Few pests bother spinach. The most likely insects to attack your crop are leaf miners. These are worm-like larvae that live between the top and bottom layers of a leaf. There, safe from pesticides and predators, they happily munch away, leaving a trail of brown, dead tissue. Since we don’t appreciate that kind of protein in our spinach salads, the best solution is to pick the affected leaves and dispose of them where they can’t re-infect the plant.
So, which variety should you plant? Some types are more or less savoyed. The more wrinkled the leaves, the harder to remove grit before eating. Breeders have also created some varieties with some resistance to various diseases. While spinach tends to be disease-free, if you’ve had problems in the past, that’s another trait to look for.
Perhaps flavor is your primary consideration. David Whiting tells the story of a grad student assigned to a research who was comparing spinach varieties. One of this student’s duties was tasting each variety and recording his impressions on flavor, texture, and overall palatability, both cooked and raw. The only problem was—he hated spinach!
After several weeks of struggling to chew and swallow mouthful after mouthful of green leaves, the grad student was astonished to discover a variety he not only could tolerate, but that he actually liked! When he came requesting a second helping, the researcher knew he had a winner on his hands. That variety is Melody.
Since hearing Whiting’s story, I’ve been recommending Melody spinach ever since. I just wish someone would let me know if they liked it!