2024 Spring Spinach Trials and previous ones

Our sparse spring 2024 late spring spinach variety trial.
Photo Pam Dawling

I have conducted trials of spinach varieties before, such as when our long-time favorite Tyee was dropped by the market. Now we need to look again.

Winter 2017-2018 spinach trials

February 5 photo of our 2017-2018 winter hoophouse spinach variety trial.
Photo Pam Dawling

We compared Avon, Reflect, Acadia, Escalade, and Renegade in the 2017-2018 winter in our hoophouse and outdoors. We were looking for a dark-leaved savoy type, with good cold tolerance and good bolt-resistance once spring arrives.

Our observations for the hoophouse were

  • Renegade made fast early growth in November and December
  • Acadia and Escalade won on early harvests (December and January).
  • The smoother-leaved Renegade had thinner leaves 4/10, and therefore a lower weight yield.
  • Acadia and Escalade won in the hoophouse on 4/24, for bolt resistance and thick leaves
  • Acadia won on bolt-resistance in the hoophouse on 5/1. Escalade was not far behind.
  • Reflect won on 4/25 over Avon on bolt-resistance in the 4th hoophouse planting.
  • Acadia won on 4/25 on bolt-resistance in the 5th hoophouse planting (late January).
  • There was no clear winner between Reflect and Avon on bolt-resistance in the late hoophouse transplanting from the 4th and 5th sowings.

For outdoor spring plantings:

  • Avon won on productivity over Renegade on 4/26
  • Reflect won over Acadia, Escalade on 3/21 and 4/26.
  • No winner between Avon and Renegade on 5/2
  • Reflect won over Avon on 5/2.
  • Reflect and Acadia won over Escalade for productivity on 5/2. Of the two, Acadia had better color.
  • Escalade may have been more bolt-resistant.

I also wrote about Success with Spinach for Fall, Winter and Spring. That post includes tips for growing spinach, as well as observations on varieties going into the winter.

From that complicated picture we could have chosen different varieties for different times and places, but we came down in favor of Acadia every time, with Escalade as a close second. Now I hear Acadia is being withdrawn and we must switch again.

Earlier winter spinach trials

Tyee spinach in our hoophouse in October 2002. Photo Twin Oaks Community

For those wanting to dig deeper, here are my earlier blogposts about spinach variety trials

Oct 4, 2016: Three spinach varieties (Tyee, Avon, Chevelle)

October 2016:  Sowing Tyee, Avon, Chevelle

Feb 21, 2017 : Spinach overwintered in a coldframe; Transplanting the last Tyee, alongside Reflect and Avon in spring.

February 6, 2018Spinach Variety Trials (Tyee, Chevelle, Avon, Reflect, Renegade, Escalade and Acadia) and Planting Plan. Details of the varieties.

April 10, 2018: Spinach Trials Update

2024 Spring Spinach Bolt-Resistance Trials

Meanwhile I agreed to trial five spinach varieties for bolt-resistance. It would be gratifying to have a spinach variety more resistant than Acadia. I sowed Sunangel, Tarsier, Seaside, Kolibri and Lizard to compare their bolt-resistance. Sowing from mid-March to early April is much later than I would normally do here in central Virginia, so it would be a real test. I had 4 sowing dates each a week apart and three reps of each variety to even out any “unfairness” due to differences between bed edges and middles. It was all over by June 7.

I kept a spreadsheet, and included air temperature high, rainfall, irrigation, and after a while, soil temperature every Friday when I did my monitoring.

I didn’t get to harvest any spinach from this trial, as the number of plants was small, but I did see some clear differences in bolt-resistance. Sunangel is clearly the least bolt-resistant, by a long way. Kolibri is clearly the most resistant of the five under our conditions. Tarsier was second to Kolibri after a gap.

Bolting Sunangel spinach on April 21.
Photo Pam Dawling

We had challenging conditions:

During March we had a lot of rain, and we were unable to till in the wheat cover crop and prepare the bed and sow when we hoped.

I pre-sprouted the seed for the first sowing (“3/15″) for a week, and sowed it 3/22, the same day as the second sowing. By then we had tilled the too-wet bed roughly.

A week later, 3/29, some cover crop was poking through and regrowing, and the soil was still very wet.

A week after that (4/5) the soil temp was 58F. Germination was poor for all varieties in the first three sowings. We made the fourth (last) sowing. The weather turned to drought (the bed got overhead irrigation once a week). Air temperatures reached 89F, although the soil was still 60F.

All germination rates were poor, some very poor, which I attribute to the conditions. The first sowing of Sunangel started bolting 4/21.

By 4/26 the soil temp had reached 70F

After three weeks of no rain, we got a lot, 1.8″ one week, 2.1” the next. Daytime temps reached the high 80’s.

On 5/31 we got an outbreak of what I think was downy mildew. All varieties were equally affected. The second sowing of Sunangel started bolting.

It was another week before the first sowings of the other varieties started bolting. Kolibri was noticeably most resistant in all sowing dates.

Our winter favorite, Acadia, is currently still available from High Mowing, Pinetree and Harris. Escalade and Kolibri are available from Stokes. Kolibri is good at bolt-resistance, but not DM resistance and I’ve no idea how it does in the winter. We can try it next winter. Space is the variety often grown commercially. It has high DM resistance and claims to be for all seasons.

What triggers bolting?

Hoophouse spinach Top row: bolting Renegade; nearer row: Escalade.
Photo Pam Dawling

I wrote a post a few years ago What makes vegetable crops bolt and how can I stop it?

This article from Michigan State University also does a good job of explaining how cold temperatures trigger bolting (flowering) in spinach and other crops.

4 thoughts on “2024 Spring Spinach Trials and previous ones”

  1. Pam, your 2021 article (linked in your column) about bolting was an eye-opener for me. I understood crops bolting in heat, especially if they are planted too late in spring or are older, but I had no idea about cold affecting brassicas. This line, in particular, helped to explain what had been perplexing to me: “Unsettled weather (cold nights, hot days, late frosts) early in the season can cause biennials to bolt.” I appreciate the link again. Of spinach, we purchased Kolibri, Red Tabby, Lizard, and Space from Johnny’s for our zone 9a California Foothills garden. Fall planted Kolibri was vigorous, sturdy, and delicious. Red Tabby has small beautifully veined leaves but was tough textured. Space was not quite as early producing and vigorous as Kolibri, but later to bolt by about a month, and is still edible even now as it bolts, mid-June. Spring-planted Lizard did well in our summer heat, although it is a bit leathery (probably why it survives the summer). I will plant both Kolibri and Space again in fall, and Lizard for summer. Both are comparably DMR. Your trialing is immeasurably helpful!

    1. Thanks Barbara, What you say about Lizard doing well in the heat but being a bit leathery is useful. You might try Kolibri for spring sowing too, although it does sound like Space and Lizard do well for you. I’ve forgotten where you are, and what kind of summer weather you deal with. I’ll also take on board what you say about DMR of Kolibri and Space. Shannon’s comment gave me food for thought on that.
      Pam

  2. People here in TN like “Flamingo Improved” a lot. I also like “Kolibri.”
    About the yellowing problem: I have that every spring. Recently I tried a boost of nitrogen in the form of fish emulsion to see if that would help. Within a few days, the yellowing was gone!

    1. Hi Shannon, your comment about the yellowing problem being solved by adding nitrogen gave me something to think about. Although we did spread compost on the bed before turning under the winter wheat, we planted soon after, because we were running late. Maybe the cover crop was tying up some of the nitrogen? I did, however, see purplish fuzzy spots on the undersides of the leaves, which I thought fitted the description of downy mildew. Given that others say these are DMR varieties, I should take the nitrogen-shortage idea seriously. We are in a region that gets a lot of DM.
      Pam

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