I need to begin this article honestly: potatoes have been a crop I whine about growing, especially on a commercial scale. But with the right inputs and equipment, potatoes can be great to grow, as well as eat. Years ago, traveling in Peru, I walked through fields of colorful flowering potatoes, marveling at the healthy plants and lack of diseases, pests and weeds. Although I never learned the techniques the Peruvians use to grow such gorgeous plants, there are a few critical practices that can help us grow organic potatoes successfully in our own corner of the world.
Potatoes require specific soil nutrients, more than most vegetables, and the yield benefits justify the extra money and effort to provide them. Planting a cover crop in advance of your spuds will help suppress weeds, improve soil organic matter, and, if you grow a legume, provide nitrogen for the potatoes. The New England Vegetable Management Guide suggests 120-180 pounds of nitrogen per acre of potatoes, with 2/3 of your total N applied at planting time and 1/3 applied as a side-dressing just before your first hilling. Make sure you also provide the recommended phosphorus and potassium for your potatoes—do a soil test or contact your local cooperative extension to determine how much additional P and K your soil needs.
One of the key elements to growing organic potatoes successfully is selecting varieties appropriate to your soils, pest and disease pressures, and markets. High Mowing has a great comparison chart that allows you to compare varieties by maturity, yield, and disease resistance, among other qualities. Perhaps what I’ve become most attuned to over the years is the varying disease and pest resistance among potato varieties. For instance, Potato leaf hopper is a serious problem for many growers in the northeast, and knowing which varieties are the least affected by it can be critical (see this Cornell study). If late blight is a persistent problem in your area, select a resistant variety such as Yukon Gem.
Potatoes require special attention to soil moisture, as they’ll suffer with too much or too little. In cold, saturated soils, potatoes can rot just after they are planted, and in rainy years they suffer from diseases attracted to their wet foliage. However, since potatoes are relatively shallow-rooted, their irrigation needs cannot be neglected, especially on sandy soils. Tuber initiation and development is a critical time for water (around 30 days after planting). As the tuber bulks up, water management can dictate the size and ultimate yields of your potatoes, and can help prevent Scab, brown scarring caused by too little soil moisture.
Although many growers utilize a whole range of specialized equipment for growing potatoes, there really are just a few key equipment acquisitions. Hillers are critical for any significant plot of potatoes. Mechanical hillers can also do double duty by burying weeds in hard-to-cultivate places.
Hillers can be easily cobbled together at home, and can fit any scale machine, including horses or BCS walk-behinds. Your first hilling should occur when the plants are 6-8” high, then again one or two more times until the plants are 10-12” high. It’s important to exercise care when hilling, since you can accidentally damage tubers or prune the roots if you get too close to the plants.
Another critical piece of equipment with potatoes is a sprayer. Regardless of your scale, you need to be prepared to spray for Colorado Potato Beetle (CPB), Potato leafhopper, and perhaps late blight. Be sure to scout potatoes thoroughly and regularly. Sprayers come in all sizes, from hand pump to battery powered backpack sprayers to tractor-mounted sprayers. Clearance can quickly become an issue for tractors driving through potatoes, so either make sure you have high clearance, or plan your fields with drive rows.
Potato diggers pay for themselves quickly once you grow any volume of potatoes. Again, these are available for all scales and are relatively easy to find used.
Even though I started out as a spud naysayer, I’ve learned that taking pleasure in growing potatoes simply means appreciating the techniques and the careful attention the plants require. I doubt I’ll ever grow potatoes as artfully as the Peruvians do, but it’s an honor to try.