Growing potatoes in the East Bay

Yukon Gold and Kennebec spuds from a San Ramon garden.

There is nothing more fun, relative to growing vegetables, then harvesting container-grown potatoes.  It’s just like digging for buried treasure! Your hands swim blindly beneath the potato plant until they discover a tuber.  You carefully explore the girth wondering as you go “Will this one have to wait, is it perfect size for a new potato, or is it a super spud ready to grace the stew pot or roasting pan?”   When you extract that beautiful potato and brush the dirt off, you can hardly resist diving in for another "search and discover mission"! 

There are, of course, other reasons to grow potatoes. For one, home grown potatoes are far tastier than any spud you will buy at the store – so creamy and buttery you won’t need to add anything other than salt and pepper, or maybe a little chicken broth or salsa.  Second, potatoes provide more protein calories per acre than any other crop, and are so nutritious you can live on nothing but potatoes for quite a long time, as the Irish peasants did until the great Potato Famine.  Last, potatoes are fairly easy to grow, especially in the mild weather that most of the East Bay enjoys.

Hilled potatoes in a San Leandro garden.  Carol Rossi

Seeds or Seed Potatoes?

Seed potatoes are basically hunks of potato with sprouted “eyes”, as opposed to actual potato seeds.  The one advantage sung by suppliers of potato seeds is that they produce smaller plants; which is great if you have limited space.   But they also produce smaller yields and smaller potatoes and take much longer to mature.   Advice for East Bay gardeners: go with seed potatoes and buy them certified disease-free from a reputable vendor.  (You can also plant market potatoes, but you have no guarantee they will not transmit virus diseases into your garden.)

The Contra Costa Master Gardeners  recommend Kennebec potatoes for East Bay gardens, but seasoned growers also claim great success with Yukon Gold and fingerlings.   California Long Whites are recommended for the warmer interior areas of the East Bay (like east Contra Costa and Alameda counties) but are, quite frankly, boring. 

One pound of potatoes plants a row approximately 8 feet long.  Many of the seed potato suppliers have calculators on their website to help you determine how much to buy and plant.

Prepare for Planting

This is a process called chitting (sprouting).   Chitting helps ensure better, quicker stands of tubers and higher yields.  To chit your seed potato set them out in open flats in indirect light and mild temperatures (55° to 65° F) about two or three weeks before planting to encourage “eyes” to sprout.  The goal is to obtain at least 2 eyes for each 1” to 2” piece of tuber.  Once the sprouts are about ½ inch long, cut the tuber into pieces approximately 1-1/2” long weighing about 1-1/2 to 2 ounces each.  Make sure each piece has at least two eyes.  (Potatoes less than 2” can be planted whole).  Allow the cut potatoes to “heal” for a couple days in a cool, dark place.  Inside a paper bag is good. Take care not to break the sprouts.

Classic, but boring, russets.  Microsoft Clip Art

Prepare the Soil

Potatoes like loose, well dug soil with an average nutritional content.   Use compost as a fertilizer instead of manure.   Fresh manure is way too “hot” and will cause scab.  If you used aged manure, incorporate is shallowly at least 4 weeks before planting or soil microbes will deprive your germinating spuds of vital nutrients and water.

Plant the Potatoes

Potatoes are a classic spring crop so set them out about 3 weeks before your last spring frost date but make sure soil temps are at least 45°F (warmer is better).  New potatoes only form above the chitted seed spud, so the deeper you plant it the higher your potential yield.   If you plant them direct in the garden or raised beds, dig a trench 2 to 3 feet deep, set them in eyes up, and cover with 3 inches of soil. 

Since many areas of the East Bay have heavy clay soil spud growers often have better success planting in containers.  Plastic garbage cans make great potato-growing containers.  If you do plant in containers, put 3 inches of soil in the bottom, set the seed potato in, and cover with 3 inches of soil. (You can cover them with up to 8 inches of soil if it is very loose and at least 60°).

Space Them Correctly

Supposedly potatoes planted on 9 inch centers (roughly 2 per square foot) will provide the highest yields, but you will get smaller potatoes.  If you want the big spuds, space them on 12 inch centers.