Planning my vegetable patch this year is an exercise in agony, because persistent disease has forced me into a position, which I once thought impossible, of banishing nightshades from my garden. Tomato spotted wilt virus has gotten the upper hand, and after losing the battle for four years in a row, drastic action is needed if I ever want to be successful at growing my beloved tomatoes again.
Potatoes, eggplant, peppers, tomatillos and tomatoes are planta non gratae in my garden and I'm suffering an existential crisis. Seed catalogs litter the table and floor near my couch, where once happy winters were spent perusing their pages and dreaming. Cover after cover depict tomatoes in glossy, full-color glory. Pages of peppers in rich hues of yellow, red, gold and purple are knives to my soul.
Nightshades have been favored for so long in my garden that I'm lost when looking through the catalogs. Listlessly turning pages, I eventually let them slide to the floor while staring out of the window heaving dramatic, heavy sighs of despair.
This lasted a week and a half, until I pulled myself up from the pit of misery, squared my shoulders, mustered up my best Scarlett O'Hara impersonation and loudly announced, "Surely there are other vegetables I can grow with abandon." My spouse, not looking up from his newspaper, nodded in a "you go, girl" way.
Thus began the search for substitutes. Cabbages, dry beans, onions and squashes fill some of the void. But sweet potatoes quickly rose to the top, since I've grown them before and they're in the morning glory clan. They store well, so even if I over plant in my forced enthusiasm, we'll be able to eat them all.
There are two types of sweet potatoes, depending on your preference. Dry fleshed types are commonly sold as sweet potatoes while the moist fleshed types are labeled yams, despite not being the true yam (botanically unrelated). Choosing shorter season types that do well in heavier soil, I settled on red wine velvet, Covington, and Porto Rico.
Red wine velvet received rave reviews for flavor and moist flesh; supposedly it makes a nice, caramelized layer just under the skin when baked. Covington, a new release, has excellent flavor and is a long storing type, which is useful to me. It's similar to standard grocery store types with drier flesh and large size. Porto Rico is an heirloom that's an early bearer of moist, delicious roots and is prolific as well.
Sweet potatoes are fairly easy to grow but the first step is amending the soil. They prefer a looser soil than our heavy clay. Incorporating finished compost into the planting bed along with a hint of nitrogen to a depth of six to eight inches is advised. However, too much nitrogen and you get all vines with little crop.
Patience is necessary. Sweet potato slips — rooted bits of plants — need settled, stable warmth of both weather and soil in order to grow. They're extremely frost sensitive and should be planted after Memorial Day; later in June if our cool spring rain (snow) lingers late into May.
Slips should be planted where they have room to grow. They're a vining plant that rambles, but the good news it that they're pretty, with heart shaped leaves. To ensure a good crop of tubers, the plant shouldn't be let to root along the vines. They should be lifted often to prevent the vines from rooting so the energy of the plant goes into one central root mass.
The slips should be planted very soon after they're received, at 12 inches apart, and the soil should be kept well wetted for at least a week. In early July it's time for a side dress of nitrogen. Harvest comes later in September when leaves start to yellow or frost has nipped the plant.
Carol O'Meara is the extension agent in horticulture entomology for Colorado State University's Extension in Boulder County. Contact her at firstname.lastname@example.org.