Growing Sweet Potato From Slips

Sweet potatoes, which are not a potato, but the sweet-tasting tuber of a plant from the morning glory family, are usually planted from sprouting vines (called “slips”).  So the first step to growing sweet potatoes is to get the vines sprouting. 

 Ideally, start with over-wintered tubers harvested last year.  All you’ll need is a container, some potting soil (I mix some seed starter in with the potting soil to help with drainage), a tray and your over-wintered tubers.

  Be sure to cut holes in the bottom of your containers for drainage (here I’m using recycled greens containers), then fill them half full of potting soil with a little seed starter mixed in.  Lay the tuber on the soil and top up with more potting mixture until tuber is 50% buried.  

Place in a warm, sunny spot, water generously, and keep an eye out for the sprouts.  Sweet potatoes love heat and moisture.  While sensitive to drought, the plants will not tolerate water-logging, so don’t overwater the soil.

Within a few weeks you should see sprouts appear.    Continue to water, and when the slips are about 5-6” tall and have a few sets of leaves, snip them with a pair of clean, sharp scissors.  If slips are pulled instead of cut, or if contaminated tools are used to cut the slip, infestations can come into contact with the plant tissue, potentially transferring disease to your new plants.  So be sure to snip the slips cleanly about ¼” above the tuber surface.

You’ll now have to let the slips develop a root system.  You can plant the slips directly into moist, warm soil, but here in Vermont that would mean sometime in June, leaving the plants an insufficient time to mature before harvest.  Instead, place the slips, cut side first, into a glass with clean water and leave in a sunny and warm spot.  Change the water regularly to prevent stagnation and to maintain a healthy environment for the slips.  Within 1-2 weeks you should spot roots developing.  

Now, be patient.  When your garden soil maintains a minimum temperature of 65°F (ideally 70°), separate the slips, being careful not to damage the root systems.  Plant deep enough that a few of the nodes are underground (typically 3-4" deep), spacing about 1' apart.  If planting in rows, maintain 3' between rows.  Water well, and keep soil moist throughout the growing season.

The sweet potatoes I grew last year were from slips provided courtesy of a friend.  I’m so excited to be growing my own slips this year from tubers harvested from those donated slips!