|Spinach plant, this is a much healthier plant than mine were.|
Like many leafy greens spinach is said to have high antioxidant levels, it is a great source of Vitamins A, C, E, K, and the B complex vitamins. It is also high in many minerals, and is considered to be a rich source of iron. Storage of spinach for more than a few days can destroy its nutritional value though, which is one reason to grow it yourself; fresh from the ground it is packed with vitamins and minerals. Spinach is also one of the 12 most pesticide-laden produce products, so even if you don't grow your own organically you should always be sure to buy it organic.
Spinach comes in three primary types: Savoy, with dark green crinkly or curly leaves; Flat or Smooth, with broad smooth leaves that are easier to clean; and Semi-savoy, with less crinkled leaves this variety is a bit easier to clean than a standard savoy.
New Zealand Spinach is actually not even closely related to spinach, it was given the name because of it's resemblance to spinach. New Zealand Spinach leaves are eaten and have a similar taste and texture to spinach. Unlike normal spinach it is comfortable growing in hotter climates, and is nearly untouched by slugs and snails. If, like me, you find you lose more spinach to the slugs or bolting than you get on your plate, then New Zealand Spinach might be worth a try in your garden.
Start your spinach seeds in the ground several weeks before the last frost date, 3 to 5 weeks is acceptable. In my garden it's pointless to start spinach this early since my garden beds don't see sunlight until April, I start spinach at the end of March. It takes about 7 weeks to reach full size, but can be harvested a few leaves at a time after the first 4 weeks or so, when the leaves are large enough to be worth the trouble to harvest. According to SFG standards spinach can be planted as close as 9 plants per square foot.
At my house, early Spring is slug season so I rarely see much spinach at all. In fact, I likely won't even be planting it this year since I lose so much to the slugs and most of the rest to bolting. For those who want to plant it be sure to protect it from slugs, and if needed shade it from the heat to prevent bolting. Some tips for doing this can be found in my posts "Slugs and Snails and Puppy Dog Tails" and "Bolting Is Bogus".
Since spinach is so very happy to bolt like crazy, make sure to plant open pollinated varieties and let them go to seed when they bolt. You can essentially have free spinach seed for life! Last year my spinach bolted the first week of June, set flowers that attracted pollinators to the garden, went to seed, and dropped the seed by early August. Then that dropped seed sprouted just as the weather began to cool, and a second crop popped up for fall. Not a bad system when you think about it.
As a final note, while spinach can be a bit touchy, and is appealing to certain slimy pests; it also grows quickly, is packed with nutrition, and is very versatile in cooking. Give it a shot, and enjoy.
"I'm strong to the finish, cuz I eats my spinach!"--Popeye the Sailor Man