Seed Potato ‘Red Norland’ (Solanum tuberosum)

Ideally water should only be applied to the root zone – an area roughly 6-12” (15-30cm) from the base of the plant, not the entire plant. A soaker hose is a great investment for keeping plants healthy and reducing water lost through evaporation. Hand watering using a watering wand with a sprinkler head attached is also a good way to control watering. If the garden area is large, and a sprinkler is necessary, try to water in the morning so that plant foliage has time to dry through the day. Moist foliage encourages disease and mold that can weaken or damage plants.

Thoroughly soaking the ground every 2-3 days is better than watering a little bit daily. Deep watering encourages roots to grow further into the ground resulting in a sturdier plant with more drought tolerance. How often to water will depend on rainfall, temperature and how quickly the soil drains. Keep in mind that the potatoes are growing underground and will not do well in soggy wet soil. Even if the plant foliage looks okay, if the soil is noticeably waterlogged this could cause problems with the development of the potatoes. Take care not to overwater as well.

To check for soil moisture use your finger or a small trowel to dig in and examine the soil. If the first 2-4” (5-10cm) of soil is dry, it is time to water.

Potato plants produce attractive little flowers, but because the focus is on root development, not flowering, it is okay to pinch off flowers. This will encourage the plant’s energy to go into the development of roots and potatoes instead of flowering and seed production. If the plant grows tall and starts to lean a stake or two can be provided for support. Loosely tie the plant to the stake.

Harvest time depends on how the potatoes will be used. Harvest new potatoes two to three weeks after the plant finishes flowering. Carefully dig these small potatoes from under a potato plant so that you don’t damage the roots. Dig up full-grown potatoes to eat promptly when the leaves begin to die. For storage potatoes, allow the leaves to die back then stop watering for two weeks but leave the potatoes in the ground to allow their skins to harden for storage. Harvest in the morning on a cool, dry day and carefully dig up the potatoes using your hands or a small garden fork.

Plants should be fertilized every 4 weeks, ending approximately two weeks before harvest. Choose a fertilizer that is high in phosphorus and potassium and lowest in nitrogen. This nutritional balance will encourage the best root (potato) development. A granulated 5-10-10 fertilizer or liquid equivalent should do the job. Be sure to read package directions for any special precautions and information on the best method of application.