Thursday, May 12, 2016

Growing Sorrel (Rumex acetosa): A Refreshing Perennial Leafy Green

I apologize for not updating the blog more frequently.  I recently re-entered the work force, and it seems like I never have time for doing the things I need to do  The garden, however, is as productive as ever.  When I get around to it, I will make an update on all the new stuff I've planted and all the new tricks I've learned this year.  But for today's post, I want to talk about a plant I've been growing for well over a year now that has rapidly become one of my favorite leafy greens.  That plant is Rumex acetosa, more commonly known as sorrel.


Sorrel is a leafy perennial herb belonging to the Polygonacae family, more commonly known as the buckwheat family in the US. Wild sorrel plants are frequently found in moist grassland areas all over the world. Sorrel is also cultivated as leafy vegetable or culinary herb.

Pliny the Elder describes sorrel as far back as 77 AD.
One of the earliest recorded mentions of sorrel being used as a vegetable comes from Pliny the Elder of the early Roman empire. In Book XVIII of his encyclopedia titled Naturalis Historia, completed in 77 AD, Pliny notes that sorrel "...is the hardiest of all vegetables, for where it once seeds, there it grows forever; neither can it be killed, do what you will with the earth, particularly if it be near the water."

Indeed, sorrel will happily grow in most climate zones ranging from USDA zone 3 to zone 9. Here in my city of Asheville, with the temperate climate of zone 6/7, sorrel is one of the first edible greens to appear in the spring, and one of the last to remain growing in the fall. It also seems to prefer acidic soils.  Sorrel will tolerate full sun to part shade, and will generally grow well without much human intervention. Although it prefers to be kept moist during the first year of growth, sorrel's roots quickly dive deep in the ground--four feet or more by some accounts--which allow it to access moisture and protect it from harsh winter conditions.

Sorrel readily germinates in a winter sowing container, where it can later be transplanted to the garden.
There are a few different varieties of sorrel as well. Rumex acetosa, also known as French sorrel, is the most commonly cultivated variety here in the US, and it is the variety I currently have growing in my garden here in Asheville. Rumex scutatus, commonly referred to as buckler-leaf sorrel, is touted as superior to French sorrel in terms of flavor and texture, but has smaller leaves and is not quite as vigorous as R. acetosa. Additionally, there is Rumex acetosella, also known as sheep sorrel, which is generally considered a weed that is prone to growing in recently disturbed areas with dry, acidic soils. R. acetosella spreads rapidly via runners and seed dispersion, and it can quickly become invasive in the garden if not properly managed.


In zone 7, sorrel is large enough to eat by the first week of March.
I use the leaves of sorrel for salads, smoothies, veggie burgers, and as a topping on nachos.  There are also many more culinary uses for it. The leaves have a sour flavor, almost like a mixture of lemon juice and a sour candy apple. Its leaves' zesty flavor can be added to soups for an extra "zing," or as a base for lemon-y sauces or pesto. Cooking the leaves makes the flavor a bit more mild, although, much like spinach, it cooks down considerably. Using a lot of leaves will be necessary if it is to be the centerpiece of a meal.

Sorrel is also a very healthy food to consume. One cup of chopped sorrel has 4 grams of fibre, 3 grams of protein, 5000 IU (106% DV) of Vitamin A, 64 milligrams (106% DV) of Vitamin C, plus a decent amount (10% DV or higher) of iron, magnesium, potassium, and manganese. That same cup only has 30 calories, making sorrel a highly nutrient-dense vegetable.  Sorrel also contains polyphenols thought to be beneficial to human health, including the well-known chemical resveratrol.

By May, the plant is bursting with huge, edible leaves.
 One thing to keep in mind about consuming sorrel is its oxalic acid content, which is what gives the plant its characteristicly sour taste. For most people, consuming foods with oxalic acid poses no health risks. However, there is some evidence that eating large amounts of oxalic acid-containing food may increase the risk of kidney stones, gout and rheumatoid arthritis in some people. For that reason, it may be wise to enjoy sorrel in moderation--perhaps no more than a few times per week. Boiling sorrel and discarding the water before consuming also reduce its concentration of oxalic acid by as much as a third.

In closing, I think sorrel may deserve a spot in your garden, as it easy to grow, exceedingly hardy, remarkably palatable and highly nutritious. Perhaps more importantly, it is an edible perennial plant, meaning reduced work for you and an improvement in your soil's biology, since the soil won't have to be tilled and seeds planted each year. Much like Pliny the Elder, where you once set seeds of sorrel, you will likely have it forever.