to download a PDF of this article.
These potatoes will be shipped to you sometime in the second or
third week of February.
Green-sprouting. Begin your hoop-house potato
cultivation by green-sprouting the seed. The basic concept of this
practice is to encourage the seed piece germination in a protected
environment. Market farmers can easily convert their walk-in coolers
to green-sprouting rooms, and while smaller growers consider the
window sill of their bedroom, as this process requires no irrigation.
Spuds should be spread out in crates or on racks, no more than two
layers tall, during the initial week-long period of 70-75 degrees
Fahrenheit required to break dormancy. After a week, the spuds have
germinated, and temperature may be reduced to 45-55 degrees Fahrenheit,
and natural or artificial light should be added into the sprouting
environment. Heated seedling houses or walk-in coolers can host
this three or four week “greening period” as the sprouts
begin to develop. Click here for MOFGA's detailed article on green-sprouting:
Hardening-off your seed. Once nightly temperatures
are reliably above 20 degrees or so, you can harden-off the sprouted
seeds in your unheated greenhouse. Expect to move your sprouted
spuds outside at the end of March or early April, definitely after
maple sugaring season. Cover your stacks of hardening-off seeds
with a few layers of row cover to ease the transition, but make
sure the plants still have access to light, crucial for their development.
Bed Preparation. Prepare the beds as you would
any early, indoor crop, and dig furrows at least 18 inches apart.
In-furrow fertilization is crucial for the successful production
of any greenhouse crop, especially heavy feeders like potatoes.
Here is a planting mix we like:
• Slow Release
Azomite: 2 pounds per 100 feet of row
• Kelp Meal: 2 pounds per 100 feet of row
• Bone Char: 2 pounds per 100 feet of row
• Fish Meal: 1 pound per 100 feet of row
• Neem Cake: 1 pound per 100 feet of row
Planting. Plant into your furrows, spacing at
6 inches for baby potatoes, and 9 inches for a little bit larger
new potatoes. Click here for Washington State University's studies on spacing
and yield for baby and new potatoes.
Cover the seed with soil and up to two layers of Agribon-19 for
extra heat retention in the soil.
Caring for the crop. Irrigate with drip tape
two or three days a week for a few hours, as needed. For best results,
either fertigate or foliar feed with fish and kelp. Early season
crops tend to wake up pests who like warm weather and tender foliage.
We recommend preventative control of Colorado Potato Beetle with
Neem Cake directly in-furrow during planting to repel and irritate
eggs, larvae, or adult beetles. If you skip this step and run into
pest problems, use OMRI approved Entrust as a foliar application.
Harvest. Pick in early to late June, depending
on the variety. Usually while your squash and melons are just a
few inches tall, you will have marketable potatoes and a market
hungry for substantial vegetables.