The way to Boost Shallots, Potatoes and Onions at Pots
Anyone with a sunny patio, deck or other outdoor place can grow shallots, potatoes and onions in pots. Shallots are perennial plants; the most common variety is that the red shallot (Allium cepa var. Aggregatum), which grows in U.S. Department of Agriculture plant hardiness zones 2 through 9, however grey shallots (Allium oschaninii), hardy in USDA zones 5 through 8, are thought by some to taste much better. Potatoes (Solanum tuberosum) are annuals, and onions (Allium cepa) are biennials that most people grow as annuals. Shallots, potatoes and onions have different care needs when grown in containers.
Potting Soil and Containers
Well-drained potting soil and containers with drainage holes are critical for growing shallots, potatoes and onions in pots. Ordinary garden soil is not suited to container gardening. Grow shallots, potatoes and onions in a free-draining commercial potting soil mix or make your own using 1 part sterilized garden soil, 1 part perlite and one part sphagnum peat moss. To sterilize garden dirt, set it in a glass pan in the microwave for 15 to 20 seconds. For each bushel of homemade potting soil, add 1/2 cup dolomitic limestone and 1/4 cup super phosphate. Grow shallots and onions in containers 6 inches deep and one foot wide or wider, and grow potatoes in containers that are at least 15 gallons and about 24 inches tall. The containers can be made of clay, plastic, metal or a rot-resistant wood like redwood or cedar.
Shallots in Pots
Shallots thrive in full-sun, dry conditions in pots. Grow shallots in containers in a site that receives at least six hours of sunlight each day, and space the shallots 6 inches apart. If the container is broad enough to grow rows of plants, then place the rows 10 inches apart. Water the shallots when the soil is dry to a depth of 1 inch. Pour water slowly over the soil surface until it flows out of the drainage holes, then cease. Shallots typically need about 1 inch of water daily, but they might need daily watering in warm, dry conditions. Fertilize shallots from early spring until the bulbs start to swell. Every week, apply a liquid 24-8-16 fertilizer product diluted at a speed of 1/2 teaspoon per 2 gallons of water. If using another item, dilute it at twice the manufacturer’s recommended speed. You can save modest shallots for next year’s crop.
Potatoes in Containers
Growing potatoes in containers entails adding layers of potting soil as the plants grow. Grow potatoes in containers in full-sun websites. Evenly space three or four egg-sized seedling potatoes on a layer of potting soil 3 to 4 inches deep, and spread two inches of potting soil over them. Pour water slowly over the soil surface until it flows from the drainage water and holes the potato plants when the soil surface is dry to a depth of 1 inch. After the potato shoots are 6 inches high, then apply fertilizer. Dilute 1/2 teaspoon of a liquid 8-0-0 organic pesticide in 6 cups of water, and pour it over the soil surface. Spread 3 inches of potting soil above the garlic shoots. Apply more fertilizer solution and potting soil in the same amounts whenever the flames reach 6 inches tall. Discontinue when the potting soil is 2 inches below the basin rim. New potatoes are ready for harvesting when the plants have flowered, or you can harvest older potatoes when the flames have died down.
Onions grow well in containers using frequent watering and feeding. Place the container in a full-sun site, and space onions 2 inches apart. Water the containers when the potting soil surface is dry, applying water slowly until it looks through the drainage holes. Feed onions using a liquid 24-8-16 fertilizer product diluted at a speed of 1/2 teaspoon per 2 gallons of water. Apply the fertilizer solution every week. You can harvest onions to be used as green onions, or permit them to create bulbs. Bulb onions are ready for harvesting when the leaves have expired.