When You Bring your Seed Home
Store the seed potatoes in a cool, dark place with some humidity.
Two weeks before planting, bring the tubers into a warm area (65˚-
70˚ F) out of direct light to let them wake up. This will make it easier to cut your potatoes into planting size chunks because the “eyes” will start to sprout.
Preparing the Soil
Potatoes like any well-drained fertile soil. Prepare the soil by spreading
and working in compost or aged manure. You can also add some balanced granular fertilizer.
Planting Your Potatoes
Seed potatoes are subject to decay when they are exposed to hot, dry
soil or cold, wet soil. The soil temperature should have reached a temperature of about 50°F-70°F, or when the dandelions bloom.
You may either plant whole seed pieces about the size of a hen’s egg,
or you may cut larger tubers into pieces with 2-3 eyes each. Plant
fresh-cut seed pieces immediately into warm moist soil, 10”-12” apart
in furrows 4”-6” deep. Space the rows 32”-36” apart. Cover the seed
pieces with 2” of soil. If your soil is on the cool side, allow your freshly cut pieces to heal for about 24 hours before planting.
Use one pound of seed potato to plant 5-8 row feet, 2.5 pounds per
12-15 row feet, 5 pounds per 25 row feet, and 20 pounds per 100
row feet.
Hilling and Weed Control
Cultivate shallowly to prevent root damage. Create a hill of soil or
mulch around the potato plant where the new tubers can develop
between the seed piece and the soil surface. The potatoes will form above the original set so hilling is a very important part of getting a good harvest. When the plants are 6”-8”
tall, gently gather the soil or mulch up around the plant until just the
top of the plant is showing. When the plant again reaches 6”-8”, hill
again, building up a total of 12”-18” of soil or mulch around the
plant. Mulching thickly with hay after hilling will keep the soil cool
and weed-free.
Watering Your Crop
Potatoes are shallow-rooted and susceptible to water stress, especially
when they are bulking. Water plants adequately to ensure even soil
moisture throughout the growing season. Stop watering 2-4 weeks before harvest.
Controlling Pests and Disease
The insect that most affects potatoes is the Colorado Potato Beetle
(CPB). Several strategies are effective in controlling these pests:
• Plant your potatoes late enough to miss the emergence of the
beetles in the spring.
• Pick beetles from plants and destroy egg masses (yellow groups of eggs on the underside of leaves), beginning two weeks after they emerge.
• Watch for larvae; brush them into a container of soapy water.
Repeat daily.
• Entrust or Monterey Garden Spray – Contains a spinosad which is
effective on a wide range of insects including Lepidoptera caterpillars.
Both products are OMRI-approved for organic culture.
The most serious disease threat for potatoes is late blight, Phytophthora infestans, a fungus that thrives in moist conditions (50˚F-60˚F
and 95% humidity). This disease is aptly named, as it strikes in late
summer when the nights are cool and dewy and when the gardens and
crops are almost done. Late blight, which thrives on live plant material of the Solanaceae family (potato, tomato, eggplant, pepper, and
nightshade), can become firmly established very quickly, destroying a
crop in just 3 to 5 days. To control late blight:
• Plant clean, disease-free seed. Infected seed is a prime source
of inoculation, enabling the disease to get established early in
the season.
Do not plant your potatoes where you grew potatoes, tomatoes, eggplant or peppers last year.
Harvesting Your Crop
You may begin harvesting any time after the plants bloom, about 60
days after planting. To find the delectable early tubers, gently rummage around under the plant, being careful not to disturb the roots.
These “babies” are your new potatoes; they’re not very big, but they
are delicious! Remember, though, that whatever spuds you steal
now will diminish your final harvest. When the tops start to die back
(senesce), the potatoes are mature. Allow the plants to finish dying
on their own, or mow or burn the tops to hurry the process along. In
about two weeks, when the tops are dead and the skins are set, dig
your potatoes.
Storing Your Potatoes
After harvesting, allow the potatoes to dry thoroughly. Gently brush
off dirt, but do not wash tubers intended for storage. Discard green
potatoes. Damaged spuds are not suitable for storage, but they are
fine for the table when eaten right away. Store your crop in wooden
crates, baskets, or burlap bags where air can circulate freely. Place
the potatoes in a dark place in your root cellar. Potatoes store best
and longest at 38˚F-40˚F with 80%-90% humidity. Under the right
conditions, you can expect six months’ storage. Save your best storage
varieties for last. Enjoy your harvest!