A customer wrote today asking if it is possible to grow rhubarb in Galena, Alaska. Galena is inland between Nome and Fairbanks and winter temperatures will drop to minus 50 F.
I think with care it can be done, though the low end for rhubarb is usually considered minus 40-minus 30 F. Here is my response to her.
Well there’s no better motivation for a gardener than a good challenge mixed with a measure of zonal denial. Rhubarb is considered hardy to -30 or -40 F. We lived in Northern Maine for a few years and saw temps go even lower though not for extended periods. Rhubarb was a great crop. You, I expect, have even colder temps and probably for longer periods. If you want to chance it, and if I were living in Galena, I’d give it a go in spite of the possibility of losing plants. Here is what I’d do. I’d dig up a nice bed for the crowns. The soil should be enriched with organic matter, leaves, manure etc. Set the crowns in this comfy bed and don’t harvest the first year. Fertilize early in the season with some form of seaweed because I think it builds a stronger hardier plant. Don’t fertilize after July 1 because you don’t want to force any late tender growth. Plant one crown in each of two large black plastic 20″ to 24″ nursery pots in an equally fertile mix. Fifty % of this mix should be commercial potting mix because of better drainage and lighter weight. Leave 4″- 5″ from plant to container soil line so you can mulch and to make watering easier. Place this out in nice sunny spot during the growing season.
Winter mulch with several inches of leaves after a couple hard frosts. Move the leaves out near your plants ahead of time so it’s an easy job when the weather turns. The two crowns growing in containers are your insurance policy. They should also be mulched, brought in to an unheated garage, an out building with a bit of wrap(burlap is great if you can find it). You want them kept steadily cold but not as cold as the outside temperatures. Once the weather begins to break move these outdoors and move leaves away from crowns. Once these start sending up shoots check your field planted crowns as they too will need to have mulch pulled aside.
You might consider low winter plastic tunnels and should do some research on the practicality of tunnels. The decision will be partly based on soil, permafrost conditions, and experience of other local gardeners. Our Garden Clips do an excellent job of holding heavy plastic to PVC pipe. Pipe is secured over a rebar stake.
The url below is about growing rhubarb in Alaska with informational links. The author has less harsh conditions than Galena but still interesting useful information.
If you’ve made it this far…sorry about such a long post but it’s info for cold climate gardeners. Last summer I spoke to Anchorage Master Gardeners and came away wowed by the beauty of the place and how these gardeners enthusiastically overcome their challenges.