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One Potato, Two Potato How To Plant Potatoes

Posted: March 14, 2016

Planting potatoes is one of the most fun and (filling) experiences in vegetable gardening.
Seed Potatoes

Seed Potatoes

Potatoes do not require any more care than other vegetables but rather particular soil needs and a good control of diseases and insects. Potatoes grow best in soil that is well drained, loose and high in organic matter. Soil that is too sandy, rocky, or clay is not good for potatoes. You may need to amend the soil by adding compost, manure or other ingredients to these soils preferably the fall before you plant potatoes.

The soil should be tilled at least 10 inches deep or double shoveled and raked. The PH for growing potatoes is 5.5 to 6.0 which is lower than most vegetables as potatoes favor a more acid soil.

A soil test can provide information to help your garden production. If a soil test is not available and the garden has been well maintained for a number of years, adding a 1-1-1 fertilizer such as 10-10-10- at a rate of 2.5 to 3.0 lbs  per 100 sq. ft,. or half that amount of 20-20-20-. for each  33ft. row. If this is a new area use a 1-2-2 ratio such as 5-10-10-at 1.4 to 1.5 lbs per 100 sq.ft..When planting a large area, side dress rows in bands, 2 inches from tubers. Fertilizing this way saves fertilizer and also does not fertilize weeds between rows.

Last years potatoes or grocery store potatoes should not be used as seed potatoes, use only certified seed potatoes which are state inspected. Potatoes need to be purchased 2 to 3 weeks before planting in order to season them. Place them spread out in a shallow box in an area with sunlight  where the temperature is about 70 degrees. The potatoes will form sprouts which will encourage quick emergence when you plant them. About 5 to 7 days before planting cut potatoes length wise and cut up into block like pieces having at least 2 eyes, allow the cut surface to heal over and toughen up during those days. These steps will help prevent rot and disease.
Plant potatoes in spring when soil temperature reaches 48 to 50 degrees or when a warming trend is predicted in weather forecast.

If the spring is wet mounding up the side of rows or plants will help drainage. Plant potatoes 3 to 4 inches deep to encourage early emergence. When small clusters of leaves emerge more soil can be added at sides when cultivating. If case of frost cover with straw or newspapers.

Potato rows should be about 3 ft. apart and seed potatoes 8 to 10 inches apart. If there is excessive rainfall a side dressing may be required at about 4 weeks., sodium nitrate 33-00 or a couple of lbs. of general purpose fertilizer is recommended.
When planting potatoes applying too much manure and lime can cause a severe scab problem, in fact apply these items the fall before you plant potatoes.

A flowering potato plant does not indicate tuber development as they actually develop 1 to 2 weeks before they flower.. A cool spring is great for potatoes as it helps expand the starches in the tubers.

Potatoes need 1.5  inches of water per week, more during dry spells. Do not water from above but by drip irrigation or soak-er hose. Weeding potatoes is essential to disease and pest control, however you can grow potatoes using plastic much. The mulch can be cut with a bulb planter every 12 inches and hand planted in rows about 18 inches apart. Drip irrigation works well with this method of planting.

Potatoes can get early blight which are small circular brown spots with a target like spot in the middle. This will kill plants and is caused by plant debris overwintering in the bed you plant them. Plant rotation is extremely important with potatoes. Donot grow in the same bed for 4 years. Clean up the garden in fall.

Late blight can happen anytime during the season. Often the source is infected tubers from the previous season. The leaves will have brownish purple lesions at the tips and can also have white mildew at those lesions. Both Early and Late Blight can be helped by using a foliar fungicide.

Common Scab is caused by a bacteria that can be in the soil for a long time, even when potatoes were not planted  in that spot. The main cause is decomposing material such as vegetable matter not cleaned up. Using an acid based fertilizer can sometimes help, or find another place to plant.

Black Leg can develop  when the weather is too wet and cool, it's a black lesion that forms on the upper stem. Healing your potatoes before planting can prevent this.
Virus diseases can be spread by insects and by not using certified seed, the plants growth will be distorted and the foliage can be mottled in appearance . These diseases can kill potatoes. Insects like Flea Beetles, Colorado Potato Beetles, Corn Borers and Grubs can attack your plants. Keep these insects under control and your crop will be safe. Look up these insects on line or in the library so you can recognize them when they come to visit. Amazingly if you rotate your crops every 4 years you will not have major problems with these pests. Wire worms can also be a problem tunneling into your tubers, avoid them by not planting potatoes in areas that are previously waste areas or grassy areas. 

The potatoes I've had the most success growing here are Dark Red Norland ,Yukon Gold and Superior.

Growing potatoes is exciting especially when harvest comes but that's another article.

Penn State Extension Adams County, is located at 670 Old Harrisburg Road, Gettysburg.  Call 717-334-6271 for further information.

By Marlene Spinoza, Penn State Master Gardener - Adams County