An Old Gardener Discovers Rhubarb
“No occupation is so delightful to me as the culture of the earth, and no culture comparable to that of the garden. Such a variety of subjects, some one always coming to perfection, the failure of one thing repaired by the success of another. … Under a total want of demand except for the family table, I am still devoted to the garden. But although an old man, I am but a young gardener.”
Thomas Jefferson, Aug. 20, 1811
Each year in Marjorie’s Garden, I like to grow something new. For 2012, rhubarb is the chosen crop, narrowly beating out another perennial vegetable, asparagus. I’m wondering, why this sudden interest in perennial vegetable crops? My only experience with rhubarb is the dessert that gives it the nickname of “pie plant”, so I don’t know if I even like the unadulterated taste of those bright red stems.
I do like the idea of a crop that you don’t have to replant every year, a crop that is ideally suited to Maine’s frigid winters and mild summers, a plant that you can propagate with an ax every few years. Something really different.
I’ve made a serious study of this vegetable that thinks its a fruit. Like celery, you eat the petioles, the leaf stalks. But you don’t even think about eating the leaves, as they contain high concentrations of toxic oxalic acid crystals. And yet the leaves make a fine garden compost, the oxalic acid breaking down during decomposition.
As for the unadulterated taste, I’ve learned that popular rhubarb recipes in this country call for a good bit of sugar to offset the tartness of rhubarb stalks used in pies, tarts, cold soups, and jams. The English, on the other hand, add ginger to their rhubarb recipes.
As with asparagus, rhubarb crowns planted this coming season will need the first year to get established and only a short week or two of harvest will be possible in 2013. By 2014, however, harvest season will run from April through June.
Planting Rhubarb in Early April
There are two ways to get started with rhubarb: order a few dormant one-year-old crowns from a garden seed company, or latch on to someone about to divide an old rhubarb plant growing in their garden, something that you will be doing a few years after planting your first crowns. In either case, you will be planting in early April, as soon as the garden’s soil can be worked.
Let’s assume you have purchased crowns. Pick a spot in your garden where you can grow three or five rhubarb plants spaced about three feet apart. For each crown, mix a shovelful or two of compost, aged manure, or worm compost into the soil where it will be planted. Make a hole slightly wider than the crown and deep enough so that it will be one to two inches below the soil surface. Put the crown in the hole and bury it, buds up.
Mark the location where each new crown is planted until the new shoots appear. And remember, let these new plants grow for the first year without harvesting any stems.
Whenever you need more rhubarb plants or when old plants become too large and crowded with stems (usually five to eight years after planting), grab a sharp spade or an ax and start dividing. Rhubarb lends itself to this kind of garden math, as long as it is done in early spring, before new growth begins.
First, dig up the entire plant with a garden fork or spade, trying to keep as many roots intact as possible. Then, using the spade or ax, divide the crown into pieces, each with at least one bud and a portion of the roots. Plant these new divisions as described above.
Rhubarb grows best on fertile, well-drained soil that is high in organic matter and slightly to moderately acid (pH 6.0 to 6.8). Given these conditions, it is a relatively trouble-free crop with no major herbivore or disease problems.
Rhubarb demands relatively high levels of nitrogen for maximum yield. This can be supplied by annual fall applications of well-rotted stable manure spread over the surface of the soil between the plants. Do not cover the plants with manure, as this will lead to rotting of the crowns. In addition to providing needed nitrogen, the manure helps conserve moisture in the soil, preserves soil structure, and makes nutrients readily available to plant roots.
Harvest begins in early May. Two-year-old plants can be harvested for two weeks, then remaining stems should be allowed to stay on the plant for the rest of the growing season. Beginning in the third year, stalks can be harvested well into June, stopping when new stalks are noticeably thinner.
When harvesting the stalks, pull them off rather than cutting them. Pulling the leaf stems causes less damage to the plant and avoids the large cutting wounds that can lead to entry of a fungal disease.
Should any flowering stems appear from your plants, cut them off. Their appearance may mean that the plant is ready to be divided or that you need to enrich the soil with rotted manure or compost.
When you start harvesting more than you can eat fresh, you can freeze the surplus. Simply chop it into one-half-inch pieces and spread them on a cookie sheet. Place the sheet in the freezer and when the rhubarb pieces are frozen, transfer them to freezer bags.