Sweet, Sweet Potato Slips

 

Flowers of the sweet potato vine. Yes, they do look like morning glories. The two are closely related. Both are species of Ipomea. However, morning glories are somewhat toxic, and every bit of the sweet potato plant is edible.

Get ready, set, 

Start! Sprouting, that is.

Last week I put my "seed" sweet potatoes in a paper bag and set them in a warm spot for the "pre-sprouting" process. About the middle of February I'll pull them out of the bag and put them in soil. You can lay them in flats or place them vertically in pots and cover lightly with damp soil. Set them in a warm, bright location and wait for the sprouting to begin -- if it hasn't already started during pre-sprouting.

When the sprouts are six to 12 inches long, cut them free and root them in either water or soil. You can plant them straight into the garden soil, if it's the right time of year. The sweet potato is a tropical plant, so the weather and soil must be warm. 

Last year I started planting sweet potatoes in mid-May (I'm in Northeast Kansas), but can wait until late June. These were robust, rooted slips purchased from a local nursery. I also planted slips ordered from Kansas State University research garden. Those slips don't arrive until sometime in the first two weeks of June, and they are not rooted. While they can be directly planted in the garden, I feel better if I root them first. It is best to root them in pots of soil, rather than in a jar of water. If you root them in water, don't crowd them or cover a lot of the stem with water, as that will encourage rotting. I also ordered some slips from a seed company. They arrived late and were in poor shape due to being shipped during the hottest days we had last summer. I put them in a pots of soil and many of them survived.

This is the first time I've tried growing my own slips. I bought organic sweet potatoes from the grocery store because we've eaten all of the white-fleshed sweet potatoes I grew last year. They must be organic, as conventionally raised ones often have been sprayed with something to prevent sprouting. I will still buy some from the nursery and K-State this year, but the ones I got from the grocery store are different varieties. I will keep you posted. 

Once you've planted the slips in the garden, water them regularly until they are well established. I often water the newly planted slips daily, especially since I'm often watering new seed beds daily at that time.  Hot sun can stress the slips and delay their recovery, so I like to shade them a bit by suspending shade cloth over the beds. And I put up temporary fencing because the rabbits and deer find the leaves much to their liking.

Once the slips are well established, you can almost ignore them, except to water in long, dry periods -- and pruning the vines so they don't cover the entire garden. I've rarely had to water mine. However, in really loose, quickly draining soil, they will need regular watering. 

When pruning the vines, go ahead and eat the leaves. The younger ones are tastier and more tender. Cook them or eat them raw. The vines produce a milky sap, but don't let that worry you.

In late September to just before the first frost in October, I will start digging. Don't leave them until after frost or the soil starts to cool a lot, as that will damage your tubers. 

For more information on a sweet potato expert, check out this video from the Douglas County Extension Master Gardeners YouTube channel. It's from the advanced education segment that followed one of our meetings.