April 2, 2000

Unless you're quite new to the Westside Gardener, you know that one of my special interests is year-round gardening - harvesting and eating vegetables fresh from the garden, twelve months a year. Most peoples' winter vegetable gardens include several different greens, but lettuce is often the primary ingredient even in December salads. Because of lettuce's importance I decided to run a variety trial over this past winter, and compare how different types of lettuce cope with our wet climate.

The trial bed in early November. Left to right: Rougette du Midi, Winter Density, Super Gourmet blend, Integrata Red, Winter Marvel, Arctic King, and Brun d'Hiver.

photo of the winter lettuce bed

For this trial I selected a number of lettuce varieties that are generally considered to be hardier than average. Several of these have been specifically bred for the cool-season garden, although not necessarily a damp rainy one! Seed was obtained from Territorial Seed Company, The Cook's Garden, and Johnny's Selected Seeds. For a control, I also planted the ‘Super Gourmet Salad Blend’ from Territorial (this will be referred to as ‘SGSB’ in this article). In past winter gardens SGSB has performed reasonably well for me, plus many knowledgeable maritime Pacific Northwest gardeners use Territorial’s seeds exclusively for their winter gardens.

While most of these are sold by reputable seed companies for fall, winter, and spring harvest, I was unsure how some would perform here. My main concern was that several of these were butterhead types, or intermediate between a butterhead and Grand Rapids. While tasty, the tight leaf structure of butterheads seems an invitation to rot in our continually damp off-season.

The lettuces were all grown in one 5’x10’ raised bed. I sowed the seed on August 12, after working 5 cups of complete organic fertilizer into the soil. The bed was in the open until mid-October, when I erected my PVC hoophouse. From then until mid-March they were pretty much protected from rain and direct exposure to frost. The bed did not require any irrigation during that entire stretch.

Since this was a La Niña winter, I assumed it would be wetter than usual. However, as you may recall, November 1999 was unusually dry for the Pacific Northwest. December was more or less typically wet. January’s weather alternated back and forth, but was probably better than average. February and March also seemed typically wet. Note: Since I haven’t yet seen the actual data summaries for this winter, these are just my impressions.

The absolute temperatures were also unusual, being abnormally mild. While the average temperatures were likely close to what’s typical in our climate, most of our region was spared from any real arctic incursions. In my garden, the absolute lowest temperature all season was only 24F. I tend to think that dampness is a bigger concern in our winter vegetable garden, though, because it’s generally easy to protect plants against short periods of colder-than-normal temperatures.

All varieties did well through December; then differences began to appear. As expected, the lettuces which had wider leaf spacing (romaines and looseleaf types) did somewhat better than the butterhead types.

Winter Density, a nice upright semi-romaine lettuce, did quite well. It’s a bit smaller than Valmaine, which is the romaine lettuce included in the SGSB. My personal preference is for Winter Density, but either of these is a worthwhile winter lettuce.

Two of the butterheads, Brun d’Hiver (BdH) and Rougette du Midi (RdM), were somewhat similar in appearance, texture and flavor. Brun d’Hiver, though, was a larger plant, and made it through the winter in much better shape than the other. This was despite the fact that BdH was semi-exposed at the end of the PVC hoophouse, while RdM was situated toward the center of the structure.

Winter Marvel (WM) and Arctic King are somewhat similar green butterheads. WM did all right through the winter, providing harvestable leaves through the season (but also a significant number of spoiled leaves toward the end). Arctic King is somewhat smaller, but in general handled the winter better – at least as well as Buttercrunch (part of the SGSB).

Integrata Red is a somewhat unique recently developed lettuce that is supposed to be markedly more cold hardy than other lettuces. In general lettuce can survive temperatures into the low 20s, so I wasn’t able to get a feel for its overall hardiness. Its growth habit is somewhat romaine-like, and its leaf spacing allows good air circulation. Integrata Red isn’t the most productive lettuce in the garden, but it seemed to do very well in our climate.

Two of the SGSB lettuces were not similar in type to the other trial varieties. Slobolt is a very nice, light green, frilly-leaved looseleaf lettuce. Despite its tight leaf structure, it handles winter very well. Slobolt is quite productive, but be warned – slugs do find it a good place to hide! Red Sails has loose, broad red-green leaves. It is a great spring lettuce, but in winter the bottom half of many leaves tend to spoil somewhat. It’s not a bad lettuce for this season, but not a standout, either.

You may wonder why Continuity – Merveille des Quatre Saisons – was not included in the trial. Basically, I couldn’t get the seed in time for sowing with the others. In the upcoming winter garden, I plan to compare Continuity with the best of this past season’s selections.

Hopefully (for the sake of the trial, anyway) we’ll get some colder temperatures next winter, so I can get a better feel for the cold hardiness of these lettuces. But it is pretty apparent that even among lettuce varieties developed for winter, some do much better than others in the maritime Pacific Northwest.

 


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This page was last updated November 18, 2013