Regiment
Spinach in the US

Spinach likes cooler weather, so timing is key to avoid it bolting too soon. For Zones 3-4, sow in April, May, July, and August. Zone 5 can start in March, April, May, then August, September. If you're in Zone 6, March, April, August, September is good. Zones 7-8 can sow February, March, April, September, October. And for those warmer Zones 9-10, you're looking at January, February, March, September, October, November, December. Sow seeds directly outdoors about half an inch (1-2 cm) deep, spaced an inch (2.5 cm) apart, in rows about 12 inches (30 cm) apart. You can sow a small batch every couple of weeks for a steady supply, you know what I mean.

Once your spinach seedlings are up and growing a bit, you'll want to thin them out. Aim for plants to be about 4-6 inches (10-15 cm) apart, that gives them room to spread out properly. If you started any indoors, get them outside once the weather settles, after your last frost date, or keep them in a cold frame. Spinach does pretty well in containers too, especially if you're a bit short on space, just make sure the pot is big enough for them to grow.