I direct seed spinach here in Santa Fe as soon as our soil is workable. I will get it in this weekend weather permitting. I always seem to wait too long but not this year!
If you have a soil or compost thermometer or if you don’t have one, you should consider getting one (I have a compost thermometer as it is longer in length), check your soil as spinach will germinate when the soil gets between 55-60 degrees. Spinach likes it cold and it has a short season here. For most varieties as soon as it gets warm, it will bolt like a cat and go to seed. We generally won’t be able to get spinach by mid May so I like to replant every few weeks to get a continuous crop instead of a large crop all at once for as long as I can. Luckily for us spinach grows quickly and most varieties reach maturity 4-6 weeks from seed.
Spinach likes to eat as it is a heavy feeder so a good dose of fish emulsion and seaweed fertilizer after it is up will really help it. If you have overwintered some spinach, fertilize it as soon as it starts to grow.
There are 3 kinds of spinach: Savoy (crinkly, thick glossy leaves) Semi-savoy (less crinkly), and Smooth Flat leaves. Here are some varieties for each type:
Smooth Flat Leaf:
If you are direct seeding, plant your seeds about 1/2 inch deep, either in rows or broadcasting them like you would a mesclun mix and just keep thinning them out, eating them along the way. If you haven’t tried fresh grown spinach, you’re in for a treat. Don’t wait too long or you’ll miss this wonderful green.