Potatoes are a staple crop, and growing them in large containers, such as an old trash can, is a widely adopted method for urban gardeners and those with limited space. This technique offers precise control over the soil environment and simplifies the often-laborious harvesting process. By focusing on vertical growth and continuous mounding, the trash can method transforms a small footprint into a highly productive space for cultivating fresh tubers.
Preparing the Container for Planting
Modifying a 20- to 32-gallon container is necessary to ensure proper drainage and prevent the seed potatoes from rotting. Several holes must be drilled into the bottom and around the lower sides, three to six inches up from the base. This modification allows excess water to escape, preventing the soilless mix from becoming waterlogged.
A larger container is generally better, as it provides more soil volume per plant, with a five-gallon capacity per plant being a good target for maximizing yield. Once the drainage holes are in place, a thin layer of coarse material, such as gravel or small stones, can be placed at the bottom to ensure the holes remain functional. The container should be placed in a location that receives at least six to eight hours of direct sunlight daily.
Step-by-Step Planting and Hilling Technique
Before planting, certified seed potatoes should be prepared by “chitting,” where they are placed in a warm, bright area for one to two weeks to encourage short, sturdy sprouts. If the seed potatoes are large, cut them into pieces, each containing two or three “eyes,” and allow them to dry for a day or two before planting to minimize disease risk.
The container is first filled with a well-draining mixture, ideally half soilless potting mix and half compost, to a depth of about six inches. Place the prepared seed potato pieces sprout-side up on the soil surface, spaced about six inches apart, and cover them with four to six inches of the soil mix. When the shoots emerge and grow to about eight to ten inches tall, the process of “hilling” begins.
Hilling involves gently adding more soil or compost around the stems, burying them up to the top set of leaves while leaving a few inches of foliage exposed. This technique is fundamental because new tubers form along the buried sections of the stem, known as the stolons. Continually adding soil as the plant grows creates a deep, vertical zone for tuber production, which is the primary advantage of this method.
Ongoing Maintenance and Troubleshooting
Consistent moisture management is important, as container soil dries out much faster than ground soil, especially in a black trash can that absorbs heat. The soil should be kept uniformly moist but never soggy. Water whenever the top inch or two of the mix feels dry, ensuring water drains from the bottom. Lack of water will cause the plants to droop and reduce the final yield.
Potatoes are heavy feeders, requiring regular fertilization after the shoots emerge. A fertilizer ratio higher in phosphorus and potassium than nitrogen is recommended, such as a 5-10-10 or a specific tomato feed, to encourage tuber development instead of excessive leafy growth. Liquid fertilizer can be applied every two weeks until the foliage begins to yellow. Hilling should continue until the soil level is within a few inches of the container’s rim, which typically coincides with the plant’s flowering stage.
Recognizing Readiness and Harvesting the Potatoes
The end of the growing cycle is signaled by the plant’s foliage, or “tops,” beginning to yellow and wilt. Once the foliage has turned brown, wait about two weeks to allow the potato skins to thicken, or “set,” which improves their storage life. Watering and feeding should cease entirely once the foliage begins to die back.
The simplest method for harvesting is to lay a tarp on the ground and carefully tip the entire container over. The loose, soilless mix and all the potatoes will spill out, making it easy to gather the harvest without using a digging fork. After harvesting, keep the potatoes in a dark, well-ventilated area for seven to ten days to “cure,” allowing minor cuts or bruises to heal and preparing them for long-term storage.