Most people don’t think of rhubarb as exotic. I mean, it’s kind of an ugly plant, isn’t it? The leaves are broad and coarse and seriously poisonous, and once you get the thing going, it will hulk, monstrously, in the garden. It’s really a huge eyesore. (Especially if you’re growing it on the FRONT lawn, at the end of the drive, as a specimen plant. But I digress). Historically, I don’t know how it happened that someone decided to pull up a stem and consider taking a bite, but my hat’s off to them, and to all the incredibly delicious rhubarb desserts that have been made ever since. Obviously the Chinese figured out that the stems (botanically called petioles) were valuable for medicine; they had been consuming rhubarb for thousands of years before medieval Europeans decided they had a hankering for the taste of the jewel-red stalks. And consider this: the high shipping costs to bring rhubarb all the way from China to Europe way back in medieval times rendered it as valuable as other botanical commodities of the time, such as cinnamon, saffron threads, and even opium. (And we think our grocery bills are expensive! No word on whether or not medieval sailor-explorers consumed quite a bit of their cargo en route; rhubarb, is, after all, chockful of scurvy-fighting vitamin C). Not bad for a perennial vegetable we tend to think of as a bit on the common side.
Once established, you could probably drive a rhubarb plant over with a very large truck and hardly do any damage (I jest, but just barely). It’s hardy, virtually pest-resistant, and depending on your climate, you can get up to two sizeable harvests in a season. Mature rhubarb has few cultural requirements: it should be watered regularly, and – most importantly – it must be fed nearly constantly throughout the growing season.
Indeed, that is the key to successfully establishing rhubarb: food. It has a thing for composted manure (not fresh, as that may burn), but it will also thrive on a balanced commercial fertilizer as well. Besides a good spring dose, and a couple more during the summer, rhubarb can also be fertilized right before frost in preparation for the next growing season. (Remember not to feed it too early in the autumn, however, as it needs to prepare itself for dormancy. Rhubarb must have a specific period of winter dormancy to be successful, making it a great choice in cold climates. It is not particularly resilient in the face of constant freeze/thaw cycles, however). Apply fertilizer around the growing plant, do not heap it on top, and be careful when incorporating it, especially if the rhubarb plant is young. They have sensitive root systems that do not like to be tampered with.
Rhubarb also likes slightly acidic soil, around a 6.0 pH. To accomplish this, you can amend with a few handfuls of peat moss; this will also assist with drainage. Rhubarb doesn’t like to sit in boggy soil, so ensure you’re not planting it in a low spot or in heavy clay. Keep rhubarb out of the hot sun – it prefers a partly shady spot where it won’t languish and wilt. Likewise, it won’t perform in total shade – it’s like Goldilocks and needs a “just right” resting place. If you want to give the tender shoots a leg up in the spring, you can cover them with a properly-sized cloche for extra protection, until the weather warms sufficiently and the danger of frost has passed. Don’t harvest newly-planted rhubarb plants until the third year – they need all their energy reserves to sufficiently establish themselves. And if you want more productive plants in subsequent years, do not harvest all of the stalks at once. Rhubarb lives fifteen years or longer, but should be divided every five years to “refresh” the plant.
And, there you have it. Those medieval Europeans were definitely onto something – they obviously knew the value of a big slice of rhubarb upside-down cake with a dollop of whipped cream!