Plant of the week: Rhubarb

Rhubarb (Rheum x hi-bred)

There is nothing like biting into a tart morsel of hot out-of-the-oven rhubarb desert or rhubarb crisp with ice cream melting over the top.  Mmmm!  Just the thought makes me hungry. :)

Rhubarb is another one of those plants that humans have long been using.  In fact according to Wikipedia, it has been used for medicinal purposes for thousands of years.  Interestingly, it seems that rhubarb roots have a 'strong laxative effect'.  My preferred use is culinary, but I'd be interested to hear if you have tried its medicinal applications.

Rhubarb is new to the kitchen.  It made it's move into the US kitchen during the World Wars (I & II) and seems to have made it's home there.  Botanically rhubarb is a vegetable but legally a fruit.  It is one of those interesting co-mingling of economics and plants.  (Botanically anything that can produce a new plant via seeds is considered a fruit and everything else is a vegetable. That means tomatoes, cucumbers and apples are fruit, but carrots, lettuce and rhubarb are veggies.)  The eatable portion of the rhubarb is the leaf 'stem', the petiole.  This being said, I must note that the leaf itself contains oxalic acid which is poisonous if ingested in large quantities!  Rhubarb may be red, pink or green and is firm, fleshy and tart.  It is harvested by tugging the whole leaf off from the plant at the base.  The leaf and the base of the petiole are both removed (and composted) and the middle portion is most often chopped up to be added to deserts or breads with lots of sugar.

According to everything I read, it can be grown anywhere in the US, but I have talked to a number of people who struggle to maintain rhubarb in locations that do not get a good hard winter freeze.  It is best to get a root cutting with 2 or 3 eyes instead of trying to start rhubarb from seed.  All or most rhubarb are hybrids and so you take your chances if you try to start them from seed.  Two to three rhubarb plants will feed an average family.  Two plants gives my family a couple of fresh uses and I freeze enough for 3 or 4 more uses.

Since rhubarb are heavy feeders, you will want to dig a large hole (or trench for multiple plants) and mix compost or fertilizer into the bottom of the hole with the dirt.  Plant the root in well drained soil with the eyes facing up about 1 inch from the surface.  Space them 3-4 feet apart if planting multiple plants.  The first year after planting, harvest lightly and allow the roots to get well established.  Once the root is well established, you can harvest fairly aggressively for about 8 weeks.  Stop harvesting when the stems become thin and spindly, a sign that the root is running low on energy.  When flowering stalks appear, remove them.  This forces the plant to put all of its energy into the root and not waste it on flowers and fruit.

All of the literature I read said that rhubarb roots should be divided and transplanted every 4-6 years to maintain the plants, but I have seen some 25+ year old rhubarb patches that farm wives have harvested every year with no problem.  I would suggest being intentional about feeding your rhubarb compost and/or fertilizer and watching it.  If it starts sending up thin, spindly stalks it is time to divide and transplant the root crown.

The National Gardening Association and NDSU extension have good posts on rhubarb if you are looking for more detail.

Happy Gardening! (and enjoy some fresh rhubarb for me this spring!)  ;)