Washington prime spot for potatoes

KENNEWICK -- I'm part Irish, so I'd like to take this week to talk about growing potatoes.

The devastation of the potato harvests by a fungal blight led to the death of at least a million of the Irish people and the emigration of a million more.

Definitely not cheery chatter, but fitting to recognize "spuds" as part of the Irish-American heritage.

While Idaho is often recognized for its potatoes, Washington comes in a close second to Idaho in potato production.

What makes Washington and Idaho great potato production areas?

The Washington State Potato Commission notes that russet potatoes grow so well here because of "favorable soil, day length, a 150-plus day growing season, proper temperatures during the growing season, warm days and cools nights during the bulking season, and controlled irrigation."

With such an abundance of potatoes grown in our region, why would gardeners want to grow potatoes in their gardens? Commercial production is focused on growing commercial varieties, especially those favored by the food processing industry. There are many wonderful specialty varieties that aren't readily available in the grocery store or that come at a premium price at local farmers markets. My favorites are some of the red potatoes, and some like fingerling potatoes or other heirloom varieties. I also think potatoes are fun and easy to grow.

Potatoes do best when planted early, about the time of the last frost date which is May 1 for our area. Potatoes are an early crop, forming tubers the best when soil temperatures are between 60 and 70 degrees. Tubers won't develop well when soil temperatures are above 80 degrees.

Purchase "certified disease free" potato seed. Novices need to know that "potato seed" isn't like bean seed or carrot seed. Potato seed is either small potatoes or 2- to 2 1/2-ounce-chunks of the tuber containing one or more "eyes" or buds.

Before planting, till the soil deeply working in some type of quality organic matter, such as compost.

Plant the seed pieces about 4 to 6 inches deep and 12 inches apart with rows 2 to 3 feet apart. When the plants are 8 to 10 inches tall, you should "hill" your potatoes. This is done by mounding the soil 8 inches tall and a foot wide along the bases of the plants in the row.

This prevents the tops of the potato tubers from exposure to sunlight which turns the skin green, making it bitter and poisonous to eat. Hilling also keeps the tubers cooler.

One of the critical factors in growing potatoes successfully is watering. You must keep the soil evenly moist. Irregular soil moisture conditions alternating from too wet and then too dry will result in knobby potatoes.

Here are several garden mail-order companies that specialize in potatoes. Check them out and get your potatoes ordered today:

-- Irish Eyes-Garden City Seeds in Ellensburg,, 509-964-7000.

-- Ronnigers Potato Farm LLC in Austin, Colo.,, 877-204-8704

-- Potato Garden in Austin, Colo.,, 970-835-4500

* Marianne C. Ophardt is a horticulturist for the Washington State University Benton County Extension Office.