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 Now I hear Acadia is being withdrawn and we must switch again.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.

Success with Spinach for Fall, Winter and Spring

January spinach from our second hoophouse sowing.
Photo Pam Dawling

Success with Spinach for Fall, Winter and Spring

Spinach is a much-loved crop for us. We sow outdoors and in the hoophouse in early September for harvesting from fall through to spring (April). We sow outdoors in late September for a crop to overwinter as small plants and be harvested in the spring. We also sow in our coldframes in mid-September. These are more sheltered than the beds outdoors, and the spinach makes faster growth. We sow more spinach in the hoophouse in October and November. We sow in the hoophouse in January to transplant outdoors and in the hoophouse in February for spring harvests. We are able to keep harvesting spinach (leaves, not whole plants) from October 15 to May 25, all the way through the winter. Central Virginia is too hot to have spinach during the summer (we switch to chard).

Spinach over-wintered in our cold frame
Photo wren Vile

Unsurprisingly, I have written about spinach several times.

Spinach Variety Trials Conclusion in May 2019. Our top general favorite is Acadia, although Reflect does better outdoors overwinter. This post includes links to earlier posts about spinach varieties, including Spinach Trials Update, April 2018.

What causes spinach leaves to turn yellow, in May 2019

yellowed spinach in May. We had transplanted too soon after tilling under some big weeds.
Photo Pam Dawling
A bed of healthy green Reflect spinach on May 3
Photo Pam Dawling

What makes vegetable crops bolt and how can I stop it? March 2021

Spinach Varieties

Choose varieties that do well in climates similar to yours, in the conditions you have when you plant and harvest. We used to grow Tyee for all plantings, and were very happy with it. But it has been pulled from the market because it had disease problems in the Pacific North West, where spinach seed is grown. We have tried and not continued Chevelle, Corvair, Renegade (grows fast, but has thin leaves and bolts early in spring), Avon (Downy Mildew in winter).

Also see the 2015 Greenbank Farm Spinach Variety Trial. The farm is in Washington State. They evaluated 10 varieties of savoyed and semi-­‐savoyed spinach with two side-­‐by-­‐side replication in spring. Abundant Bloomsdale, Bloomsdale Long Standing, Butterflay, Giant Winter, Dolce Vita, Longstanding Bloomsdale, Lyra, Solstizio, Tyee, Winter Bloomsdale. The overall star of their trial was Solstizio from Nash’s Organic Produce.

Spinach plants on February 5. left to right: Avon, Renegade, Escalade, Acadia.
Photo Pam Dawling

Paul and Sandy Arnold in Argyle, New York, made a great slide show reviewing Spinach Varieties in High Tunnels.  I think it’s no longer available online, but I did learn that in 2019, their top Winter Spinach Varieties were Escalade, Carmel, Whale, Space, Reflect; top Summer Spinach Varieties: Banjo, Seaside, Woodpecker.

In 2011-2012, High Mowing Seeds in northern Vermont did a spinach variety trial with 24 varieties. Three farmers in Iowa conducted a 2021 trial of spinach varieties and seedling methods. They compared yield, bolting and yellowing among three spinach seeding methods: seeder (1x rate), seeder (2x rate), hand-seed (2x rate); and between two varieties (Kolibri, Kookaburra). Two of them found no statistically significant difference of seeding method on yield; one found no difference in yields between the two varieties, but using a seeder at a double rate produced significantly higher yields than the other two methods.

When to sow fall spinach

Spinach does not germinate in hot soil! Use a soil thermometer and wait for the soil to cool to 68F (20C), or see the next section about sprouting spinach seed in a cold place. If you have no soil thermometer, see my post chickweed, hen-bit and dead-nettle, and use the info that was originally written with lettuce in mind, for spinach! There are photos there of these three plants at seedling stage. These are winter annual weeds here, that don’t grow in summer. Once we see their seedlings emerging in late August (a cool summer year like 2023) or September (most years) we know the soil has cooled enough to sow lettuce and spinach directly in the ground.

A trick for getting good timely germination of spinach seed is to put it (in sturdy resealable plastic bags or jars) in the freezer for about two weeks. Take the seeds out of the freezer the day before you want to sow (or start sprouting them), but – important – do not open the bag or jar. Leave it to warm to ambient temperature before opening. Otherwise the warm humid air will rush in and coat the cold seeds with condensation, reducing the shelf life of whatever seed you have left over for another time.

See our Spinach Variety Trials and Planting Plan, in February 2018:

  • September 6 is our first sowing (sprouted seeds) in the hoophouse for winter harvest 10/30-2/15, or later if it doesn’t bolt.
  • We sow outdoors on September 7 (sprouted seeds) for growing under rowcover and harvesting in fall and winter.
  • September 18-20 we sow in our coldframes and outdoors for harvest in early spring, until late May.
  • October 24 we make our second hoophouse sowing, to feed us November 25 to May 7.
  • On November 9,we make a third hoophouse sowing, intending to use these plants to fill gaps in our hoophouse as other winter crops come to an end.
  • January 16 we make more sowings in the hoophouse, some to continue to fill gaps there along the edges of the beds where they won’t fight with the tomatoes and so on, which we transplant starting March 15. Most of the spinach sown on this date is for transplanting outdoors on February 21.
  • January 29 we sow in flats in the greenhouse if we see we haven’t got enough bare-root transplants in the hoophouse.
  • February 10 If we don’t have enough transplants, then on this date we sow outdoors with rowcover, for spring harvests until May 25 if we’re lucky. We have backup plans on backup plans for this!
  • In the hoophouse we continue transplanting spinach to fill gaps until March 31.

 

Sprouting seeds before sowing is a way to success in hot or very cold weather.
Photo Pam Dawling

Sprouting Spinach Seed

This very easy work-around involves soaking the spinach seed in water overnight, draining it, and putting the jar on its side in the fridge for a week. If you remember, give the jar a quarter-turn each day to even out the moisture. You are not growing bean sprouts! A little neglect will not cause harm. The ideal is to have short sprouts, not long ones, as those break off more easily.  Sow the seed in the furrows gently, by hand. If the sprouts have got tangled, add some water to float them apart, drain them, spread them on a tray, or a layer of rowcover, to dry a bit, then mix with some inert dry soil-friendly material like uncooked corn grits or bran, which will help them not stick together.

Sowing Spinach in Speedling Flats and Floating them in Water

Another option is to start the spinach in flats and transplant it all. That’s a lot of work, but we found we could save on the daily attention time and the transplant time by using 120-cell Styrofoam Speedling flats. Sow one or two seeds per cell, then float the flats all day in water. Depending on your scale, this could be a baby bath or a stock tank. Remove the flats each evening and let them drain all night (while it is hopefully cooler). With just twice a day visits and no hand-watering, this is a big time saver, and we have got good germination rates.

Transplanting spinach from a Speedling flat. Butter knives are the tool of choice for easing the little wedges out of the tapered cells.
Photo Denny Ray McElya

When it comes time to transplant, the tool of choice is a butter knife. Use the knife to wiggle a wedge-shaped hole in the bed. Slide the knife down the sloping side of the cell, and, holding the base of the plant with one hand, use the knife hand to lift and flick the plug out. If all goes well, the plug will be then be resting on the now-horizontal knife, and you can slide it into the pre-made hole and firm it in.

Growing Spinach

Spinach makes growth whenever the air temperature is 40F (4.4C) or more. So any winter protection you can provide, in the way of cozy microclimates, rowcover, coldframes, or a hoophouse, will increase your yield. Spinach is more cold-hardy than many people realize. It dies at 0°F (-18°C) unprotected outdoors. Savoyed varieties tend to be a little hardier than smooth-leaved types. Large-leaved savoyed spinach outdoors with no protection can get seriously damaged at 10F (-12C). Small-leaved plants are OK down to 5F (-15C).

Weeding rowcovered spinach in winter.
Photo Wren Vile

Our outdoor spinach gets hoops and thick rowcover (Typar, 1.25 oz/sq yd spunbonded polypropylene, with 75% light transmission, and about 6 F (3.3 C) degrees of frost protection). It can last for 6 years or more. When we got 0F (-18C) the spinach leaves that touched the rowcover got big patches of beige/tan dead cells, but the plants recovered to produce more leaves.

Ben Hartman (author of The Lean Farm) wrote Testing the Limits of Cold Tolerance in Growing for Market magazine in February 2014. He reported that his young hoophouse spinach in Goshen, Indiana, with mid-weight rowcover survived -16F (XXX). Ben points out that spinach less than 1″ (2.5 cm) tall is very cold-tolerant. Bigger plants need more protection if it’s going to get that cold.

 You can read more about growing spinach in my Cooking Greens monthly series.

Growing bare root spinach transplants

Small spinach seedlings for bare root transplants. Photo Pam Dawling

We grow our spring spinach transplants (as well as kale and collards) in the soil in our hoophouse, sowing them in late January. See bare root transplants . You can find more links and info in that post. Growing bare root transplants saves a lot of work and a lot of greenhouse space.

Harvesting Spinach

Our goal is sustainable long-season harvesting. This is important for winter crops, as making a new sowing during cold dark days will not produce much food until spring comes around. It’s like the goose that lays the golden eggs – keep the leafy “golden eggs” coming

We harvest spinach by cutting individual leaves and leaving the plant to continue to produce more.

Our rule is “Leave 8 for later” – cut off large outer leaves close to the base of the plant, being sure to keep at least 8 of the inner leaves growing on each plant. Over-harvesting leads to decline.

When we finally pull up the bolting plants in spring, I’m always amazed to see how many leaf-scars there are on each plant, showing just how much we’ve harvested.

Hoophouse spinach. Far row: bolting Renegade; Near row: Escalade.
Photo Pam Dawling

For those relatively new to this blog but living in a similar climate zone, I want to point you to The Complete Twin Oaks Garden Task List Month-by-Month. It includes a link for each month’s task list. I notice from the site stats that some of you are finding your way there, but now there are so many years’ worth of posts it’s perhaps harder to find. Happy browsing!

Spinach variety trial conclusions

Outdoor spinach on the Spring Equinox (with peas interplanted).
Photo Lori Katz

Spinach Variety Trial Conclusions

Unable to buy our long-time favorite spinach variety, Tyee, we have tried various other varieties. This winter and spring we compared Avon, Reflect, Acadia, Escalade, and Renegade, in the hoophouse and outdoors. We are looking for a dark-leaved savoy type, with good cold tolerance and good bolt-resistance once spring arrives.

Hoophouse plantings

Sowing #1 9/7/17, all pulled up by 4/24/18, after a productive winter.

Sowing #2: 11/8 (normally 10/24, but we failed to water, and had to resow)

In November and December, Renegade had the largest leaves, so its advantage in central Virginia hoophouses is probably as a faster-growing type.

1/10/18:

  • Reflect is growing bigger/faster than Avon.
  • Renegade is faster/bigger but paler than Avon.
  • Acadia has more leaves than Avon, Reflect, Renegade.
  • Escalade is also faster and bigger than Avon, Reflect, Renegade.

4/3/18: Bolters pulled: Reflect 2, Avon 1 , other varieties zero bolters

4/10/18: The plants have not changed much in the last month, although in comparison with the February photo, you can see the leaves are starting to become pointed in shape. We are waiting to see which of the varieties bolts first. 

4/24/18: Reflect, Avon, Acadia, Escalade, Renegade. All are now growing thinner pointy leaves and starting to bolt. Renegade has large leaves, but the color is paler than the others and the texture is less exciting to us.

Counting bolted plants along the rows, I found

  • Avon 10 bolters
  • Acadia zero bolters
  • Escalade 4 bolters
  • Renegade 6 bolters.

Acadia and Escalade both had thick, well-textured leaves.

5/1/18. On My final tally date of the spinach in the hoophouse, I counted bolters:

  • Avon was much more bolted than Reflect
  • Acadia had 12 bolted, 18 not. 60% resistance
  • Escalade had 13 bolted, 17 not. 57% resistance
  • Renegade had 20 bolted, 6 not. 23% resistance
  • Avon had 19 bolted, 2 not. 10% resistance
  • Pity I did not directly compare Reflect and Acadia!
Hoophouse spinach variety trial Avon Renegade Acadia Escalade in February. (Note long shadows!)
Photo Pam Dawling
Hoophouse spinach variety trials in early April (note some cold damage). Left-Right Avon, Acadia, Escalade, Renegade.
Photo Pam Dawling
Hoophouse spinach variety trials in late April. L-R Avon, Acadia, Escalade, Renegade.
Photo Pam Dawling
Hoophouse spinach variety trials. Comparing bolt-resistance. May 1. L-R Avon, Acadia, Escalade, Renegade.
Photo Pam Dawling

Sowing #3 11/9

4/25/18: Avon – all pointy

Sowing #4 1/15 (for transplanting inside the hoophouse).

4/25/18: South side Avon – pointy; North side Reflect – bigger than Avon, less texture, also pointy.

Sowing #5 1/16 (for transplanting outdoors).

4/25/18: North side Reflect – a bit pointy, smaller than Avon and Acadia; South side Renegade, Escalade, Acadia. Acadia is bigger than Escalade, darker and more textured.

We transplanted from #4 and some #5, mostly not labelled. All look good 4/25. Avon transplanted 3/14, looks great. Big textured leaves. Reflect transplanted 3/16 – also good.

2018 conclusions for hoophouse spinach:

  • Renegade made fast early growth in November and December
  • Acadia and Escalade win on early harvests (December and January).
  • The smoother-leaved Renegade definitely has thinner leaves 4/10, and would yield lower weight (if we were weighing them).
  • Acadia and Escalade win in the hoophouse on 4/24, for bolt resistance and thick leaves
  • Acadia wins on bolt-resistance in the hoophouse on 5/1. Escalade is not far behind.
  • Reflect wins on 4/25 over Avon in the 4th hoophouse planting.
  • Acadia wins on 4/25 in this 5th hoophouse planting.
  • No clear better variety between Reflect and Avon in the late hoophouse transplanting from the 4th and 5th plantings.

We don’t like smooth-leaved spinach as much, so will maybe drop Renegade – it doesn’t shine on anything else except being earliest, but then becomes less productive.     Acadia did very well, Escalade not far behind. Perhaps drop Avon for hoophouse too. Perhaps continue Reflect, Acadia and Escalade, and do comparisons of the 3 only. Or just grow Acadia in the hoophouse.

Hoophouse spinach variety trial on May 1. Top: bolting Renegade; bottom: Escalade.
Photo Pam Dawling
Hoophouse spinach variety trial on May 1. Left of driptape: Acadia, right: Avon (see arrowhead leaves).
Photo Pam Dawling

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Outdoor Plantings

Reflect spinach in the snow in January.
Photo Pam Dawling

Outdoors we had overwintered Avon and Reflect. Both did well.

2018 conclusions for outdoor over-winter spinach plantings: Grow Avon or Reflect. Both did equally well. For simplicity, maybe drop Avon.

Outdoors in early spring, we transplanted 4 beds with Avon, Acadia, Escalade, Renegade, Reflect:

3/21/18: Reflect looked really good. Acadia, Escalade, Renegade not so good.

4/26/18:

  • Bed 15W all Avon looks good. Good size, good color.
  • Bed 16W has 3 rows Avon, 1 row Renegade (north). Renegade is smaller and lighter color – a more yellowish cast.
  • Bed 20W mostly Reflect, doesn’t look that good, partly because of lots of weeds. Avon the same.
  • Bed 23W 2 rows Reflect (south), 1 row Acadia, 1 row Escalade (north). Escalade is smaller 4/26.

5/2/18:

  • Bed 15W all Avon Good size, but all yellow, especially south edge. May have drowned. Only slightly pointy.
  • Bed 16W has 3 rows Avon, 1 row Renegade (north) Both varieties are very yellow (drowned?)
  • Bed 20W all Reflect, less yellow than Avon in the other beds.
  • Bed 23W 2 rows Reflect (south), 1 row Acadia, 1 row Escalade (north).
  • Reflect is really good where not drowned, if a little pointy.
  • Acadia is even better than Reflect, also a bit pointy.
  • Escalade is still smaller than Reflect and Acadia, also less pointed.
  • Both Acadia and Escalade are a darker color than Reflect.

2018 conclusions for outdoor spring spinach plantings:

  • Avon wins over Renegade on 4/26
  • Reflect wins over Acadia, Escalade on 3/21 and 4/26.
  • No winner between Avon and Renegade on 5/2
  • Reflect wins over Avon on 5/2.
  • Reflect and Acadia win over Escalade for current productivity on 5/2. Of the two, Acadia has better color.
  • Escalade may win later as more bolt-resistant.

We don’t like smooth-leaved spinach as much, so maybe we’ll drop Renegade.

Reflect and Acadia did well for spring outdoor plantings. Maybe drop Avon. Maybe grow mostly Reflect and some Acadia for May harvests? Escalade may be more bolt-resistant, and warrant growing one bed of four. If not, drop Escalade for spring outdoor planting?

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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 this spring.

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

April 10, 2018: Spinach Trials Update