Thursday, April 03, 2014 Grow Your Own Potatoes
Potatoes harvested fresh from the garden are full of flavor and so versatile in meal planning, plus they are a nutritional mother lode, high in vitamin C, potassium, fiber and protein, all with no fat. The skin of the potato contains the majority of the potato’s fiber and many of the nutrients are located close to the skin, so take advantage of recipes that are ‘skin on’. Potatoes are easy to grow as long as they have full sun, moderate temperatures, and light, rich, acidic, well-drained soil. Try varieties with colors, shapes and flavors you won't find in the supermarket.
To ensure highest quality and yields, purchase certified potato seed tubers. Certified potatoes have been grown under strict guidelines to produce tubers that are virus and disease free. Saving tubers from your garden to replant year after year will eventually result in decreased yields, smaller tubers and more potato diseases. Also, you do not want to plant tubers purchased from a grocery store as they have usually been treated with sprout inhibitors, and as a result, would have difficulty growing. The potatoes we sell for planting are all ‘certified’ seed stock.
PRIOR TO PLANTING: If you purchased certified whole potatoes, you need to cut and cure them prior to planting. Making planting pieces is a simple process. First, inspect the tuber for “eyes.” These are the sprouts that are contained in the indentations of the potato and will grow into potato plants. Some of the eyes are very small and you will have to look carefully for them. Cut the tubers in half and then cut the pieces so they have 1 or 2 eyes per piece. The pieces should be about the size of golf balls or no larger than chicken eggs. Small tubers can simply be cut in half. It is best if the pieces are cut 5 to 10 days prior to planting so the tuber has a chance to develop a callus tissue over the cut surface. The pieces should be kept at room temperature to let this ‘healing’ or ‘curing’ process take place. A light dusting with lime is beneficial, but not absolutely necessary. This curing process helps protect the potato piece from being attacked by soil microbes that could rot it before it has a chance to grow. If soil is warm and good quality, the curing process is not absolutely necessary. Also, if you purchased pre-cut sets, they have already been cut, dried and cured, making them ready for immediate planting.
PLANTING GUIDELINES: Potatoes prefer a well-drained, deeply worked soil that is a bit on the acid side with a pH between 5.5 and 6.0. A pH above 6.0 may result in an increase of common scab on the tubers.
Ideal temperatures for growing potatoes are 65 to 80 during the day and 55 to 65 degrees at night. Do not plant seed potatoes until soil temperature reaches 45 degrees F. We recommend a soil temperature of 55 degrees F. to be on the safe side. If soil is cold and wet, the seed may decay, and if cold and dry, sprouting may be delayed. Potatoes like a soil that is well-balanced in nutrients. Adding garden fertilizer or well-rotted cow manure and compost at planting time is a good way to supply the nutrients they need. Row spacing can be as close as 2’ where space is limited, but we recommend 3’ between rows to allow adequate space for vines to grow and enough room for hilling. Dig a shallow trench 6" to 8" deep and place the seed pieces about 12" to 15" apart in the row. Cover the seed pieces with about 3” of soil. Fill the trench gradually as the vines grow, never covering the vine once it has emerged from the soil.
HILLING POTATOES: Potatoes need a place for the tubers to grow and develop out of sunlight. When the plants are about 8 to 10 inches tall, gently mound the soil to a height of 3 to 6 inches and approximate 12 to 15 inches from the base of the plant. Use care not to damage the plant roots which may extend 8 to 12 inches from the base of the plant. Almost all potatoes form close to the seed piece. This is why it is essential that soil is mounded as the vines grow. If the tubers push out of the soil they will turn green and be inedible.
WATERING: In general, 1 inch of water per week by rainfall or irrigation is sufficient. Sandy soils will require more. The root systems are aggressive and usually find enough water. However, periods of dry soil alternating with periods of wet soil can result in poor quality tubers, so even soil moisture levels should be maintained.
An alternative method for growing potatoes is to plant seed pieces shallowly into the soil and cover with a thick layer of clean straw or other weed-free mulch. Add more mulch as needed to keep light from reaching potatoes (a foot or more of mulch may be required). Tubers grown this way can be easily harvested by pulling back the mulch after the plants die.