Seed Potatoes, Russet Umatilla

• If it is not time to plant the tubers when they arrive, place them in a completely dark, dry, cool area. If exposed to light, they will turn green and should not be planted when this happens.
• If the tubers arrive with shoots (sprouts), this does not affect the growth of potatoes. This is just nature's way of starting new life. Plant the tuber with shoots facing up.
• For best results, plant tubers up to 10 days before the last killing frost is expected. Do not plant in soil that is too cold to avoid late sprouting and rotting.
• Prepare the planting area. Potatoes can be grown in a wide variety of soils, but do best in fertile soil that is well-draining. Avoid planting tubers in low-lying spots that get water-logged after it rains as the potatoes can rot.
• Heavy and/or clay soil can be amended with well-rotted manure or compost 30 cm (12") deep before planting to improve soil structure and fertility.
• Plant in a sunny location that receives at least 6 to 8 hours of full sun.
• Large tubers may be divided, but each portion must contain two to three eyes. If using divided tubers, wait 24 hours to plant to allow the cut to callous over.
• Plant with eyes pointing up (cut side down) 2.5-5 cm (1-2”) deep and 30 cm (12”) apart in the row.
• Rows should be spaced 30 cm (12”) apart.
• Once plants are 15-20 cm (6-8”) tall, hoe 10 cm (4”) of soil up and around plants to create hills. Hills of soil around the base of the potato plants help to preserve moisture and protect tubers from being exposed to sunlight which turns them to green and not edible. As the plants grow, more soil should be hilled up around the plants.
• Water needs: A healthy, well developing potato crop can use at least 2.5 cm (1") of water per week during growth. Do not wait until you see the plants wilting before you add water. At this stage yield potential has already been reduced.

• Do not add manure to the planting area the same season you are planting as that can promote potato scab. The potatoes are unattractive but are okay to eat.
• Do not plant potatoes in the same place every year because diseases will build up in the soil.
• Potatoes in gardens are often planted too deep. The heavier the soil, the shallower the planting should be. In heavy soils a depth of 5 cm (2") is recommended. For lighter soils about 8 cm (3") is deep enough.
• Generally 1-2 weeks after blossoms appear you can begin to harvest baby potatoes. To check, simply remove some of the soil away from the hill with your hands and pull away some potatoes from the roots. If doing this, make sure to push the soil back in place. The plant will not be harmed and can still produce potatoes until ready to lift the plant entirely.
• Do not eat potatoes that have green on the outside skin as they are not mature, will be bitter and may cause illness.
• Cycles of hot dry weather, followed by heavy rains prompting sudden short periods of rapid growth, are the main causes of rough, knobby, malformed, hollow or cracked tubers. High humidity and excessive rainfall may also provide ideal conditions for the development of diseases such as late blight.

Harvesting Potatoes for Storage

• Once the plants have turned brown and died back, the potatoes can be harvested for storage.
• When the soil is dry, dig under the plants with either your shovel or your spading fork being careful not to damage the potatoes in the digging process. Once underneath the plant with your shovel or spading fork, lift the entire plant and shake the soil off of it and pull the potatoes you want from the vine. You should sift through the soil in the hole to find additional potatoes that may have broken away from the plant.
• Dry potatoes on the ground in a shaded area for 2-3 hours after harvesting, weather permitting so skin will harden before storage. Store potatoes in a cool, completely dark place with ventilation. Ideal storing temperature is between 3-5º C (35-40º F).