What we learned from our Overwintering Spinach Trial

For some reason I’m fascinated with spinach. Perhaps it’s the different colors, textures, and growth habits, but all of it intrigues me. We sell a lot of spinach on our farm: baby, leaf, and bunched.
Last year we decided to do several trials. One was in the fall comparing 8 different types, looking at growth habits, hardiness, and disease resistance. The other was a ¼ acre, 9 variety, overwintering trial, looking at the same characteristics. We are located in zone 4a, and can get quite cold during the winter.
The process started Mid-summer with identifying the area for the trial. We wanted well drained soils as spinach doesn’t like wet feet, especially during the winter. We choose a sloping, Hoosic gravelly loam that had previously been in spring greens. The field was tilled and fertilized, beds where made, and the Spinach seed was planted mid October, 3 rows on the bed, 18” apart. Seed spacing in the row was 12-16 seeds per ft.
After seeding, the spinach germinated and was cultivated once before winter covers were put on in late November for overwintering. We used one layer of Typar 518 or 2 layers of Covertan 30 weight. The winter of 2014-15 was severe, with good snow pack. The rowcover was needed, because when part of it blew off, that area died. (Thankfully it didn’t destroy all of any one variety, so we still were able to collect data from all varieties.)
Spring came on slowly, with late April snowfalls. We didn’t’ get out into the fields until April 12th when we fertilized the spinach with krehers 8-3-3, putting down 60# N to the acre. We were, however, able to check the spinach in late March as the snow receded.
One problem we had was that rowcovers on spinach can cause rubbing, or white spots on the leaves. We didn’t want to hoop the spinach, so we ended up delaying harvest by pulling row covers completely off. This was done approximately at the end of April.
early trial
We started harvesting spinach from this section the last week of April, and continued through the last week of May when the last varieties bolted.

The results: the field was evaluated on May 15th when all the pictures were taken. I evaluated bolting again at the end of May to confirm our earlier results and make any last minute observations.

A note about the pictures: We clear-cut the field early May for a wholesale order, that is why many of the leaves look a little ragged.

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Space- Solid all around spinach. A little slow growing and had a tendency for the bottom leaves to be yellow.

space
Emperor- Wow, what a great spinach. Early, tall, dark green. It did have a tendency to have deformed leaves and show some bottom yellowing. Bolted quickly as well, but for an early spinach this was great. We really like this variety for bunching. Scored low mainly because a low percentage of plants deform.

Emperor
Giant Winter- Bolted early, one of the quickest to size, but color wasn’t great. Leaves yellowed as well.

Giant Winter
Pidgeon- Best spinach overall. Sized quickly, took forever to bolt, held off disease and deformity was okay. Great color, easy to harvest.

pidgeon
Tyee – An old standard. Minimum score on all aspects was a 6. You can see why people still grow this.

Tyee
Racoon- Absolutely beautiful spinach (was our favorite in the fall trials) Very upright, easy to pick, bolted relatively soon though and flavor wasn’t great. Very good disease resistance.

raccoon
Bloomsdale- Older variety, grew a bit slower and bolted relatively soon, but scored best for flavor. Very savoyed leaf.

Bloomsdale
Regiment- Another nice variety. Not on our list to grow again since their are much better varieties.

regiment
Renegade- Second best score overall. Large leaves, slow bolting, relatively nice flavor, good disease and deformity resistance.

renegade

They say the proof is in what you grow next time, so here’s what we’re going to overwinter again. Space, Emperor, Pidgeon, and Renegade. Even though Emperor scored lower, it’s earliness and size were winners for us. Its all about what you want in a spinach, and as our overwintered spinach only has to last several weeks before the regular field plantings come in, we will take earliness and yield over bolt tolerance.

We also overwintered baby red Russian kale in the field. Of course it bolted quickly, but would have been fine for one cutting of early spring greens.

red russian kale

To check out more pictures of the trial, click here!  

What are you looking for in overwintered spinach? What varieties have you tried?