Another question from a friend on Facebook:
“Hey Tom….gardening question: once you take the initial leaves from a spinach plant, is that it? Is that thing ever going to keep giving new spinach? I have cut the flowers off of it in hopes that it will produce again, but no idea.” – Joe in the Twin Cities
Good question, Joe. Given that I (and some other gardeners I know) have had a bad spinach year here in Minnesota so far, it is worthwhile to talk about that leafy plant. The good news is that even though the plants have bolted already, we get another shot at growing spinach this season.
Growing Spinach – Spring
Spinach is one of those magical plants that we can put in the ground early here in Minnesota. We can plant spinach four weeks before the last frost in spring, and the plant does well in the cool weather. That is huge for us considering how long it takes to get warm in spring.
Plant the spinach seed 1/2 inch deep, and space the plants every 6 inches.
You can plant spinach in containers as well.
- For a Rain Gutter Grow System, you can plant 9 plants in a 5 gallon bucket, grow bag or container.
- For a Square Foot Garden, you can plant 9 plants in a single 12-inch square.
- For Mittleider Gardens, you can plant spinach in 2 rows and spaced 6 inches apart (in an 18-inch grow bed).
Growing Spinach – Summer
Once the temperatures climb to 75 degrees Fahrenheit and days get long, spinach tends to bolt. That means that the spinach plant will grow flowers and go to seed.
To try to extend your season, you can try the following:
- Pinch back the flowers. The problem is that the leaves eventually taste bitter.
- Plant seed varieties that are hardier and can withstand heat.
- Growing spinach in shaded areas or with a shade cover.
Chances are, however, that you will need to get ready for your second spinach season in the fall as your plants bolt and the leaves taste bitter.
Growing Spinach – Fall
Since spinach prefers cooler weather, we will have a good shot at another spinach season here in Minnesota. The USDA has a Plant Hardiness Map for the entire United States, and that map can be found here. Zeroing in on Minnesota, the USDA divides the state into five zones (see below):
- 3a – Band across far northern portions Minnesota
- 3b – Band across north Minnesota from Pine City to Walker and north
- 4a – Band across the state from Cambridge to Fergus Falls
- 4b – Large band that covers most the Twin Cities to southern Minnesota
- 5a – Extreme southern portion of the state near Fairmont
The Minnesota State Climatology Office shows median dates for frost in spring and winter here. Looking at the data, we should plan on October 1 being the first frost date.
Given that spinach takes about 5 weeks before you are ready for a harvest, you should plant spinach 6 to 8 weeks before the first frost. Working backwards from October 1, that means that we need to plant our second crop in early to middle August.
Growing Spinach – The Time is Now!
The timing is right to pull that bolted spinach and prepare your soil for new spinach plants. Follow the same steps as you did for the spring planting, and you should see some spinach in the fall!
This article was written by Tom Garette and first appeared on the Small Scale Gardening Blog.