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Here's a sweet experiment

When I write this column, giving suggestions or directions on how to grow something, I've actually done it. Until now.

I'm going to try an experiment, and I'm hoping some readers will join me in trying it, too.

I love sweet potatoes, and they will grow in the Rogue Valley. I have grown sweet potatoes here, but only using starts purchased from Georgia, through a seed catalog. They're kind of expensive, so my thought is, why not start the starts myself?

And therein lies the experiment. I've read about this idea, and talked to fellow Master Gardeners about it, so it's time to give it a shot. Want to join me?

Sweet potatoes, of course, are native to a much warmer climate with a longer growing season than we have. And whether they are yellow or orange with red skins, they are all sweet potatoes, not yams. Yams grow in Africa, but marketers here use the term "yams" for the ones with orange flesh. They are not potatoes, either, but instead are closely related to morning glories.

For our experiment, we'll need a few organic sweet potatoes, some jars of water, and some round toothpicks, to start. I recommend organic potatoes, because you know they have not been treated to prevent sprouting, as have regular supermarket ones. The number of potatoes is up to you. Just keep in mind we won't have much success in clay soil — they will need loose, well-drained soil, probably in a raised bed, so your available space will help determine the number of plants you raise.

To get things started, fill some wide-mouth jars with water. Then insert four or five round toothpicks in each potato, about half or two-thirds of the way up, and suspend the potato in the water, with the more tapered end down. Set the jars on a windowsill or table in bright light, but not direct sun. In a week or two, you will begin to see roots forming on the part of the potato that's in the water. Change the water occasionally so it won't attract gnats or fruit flies.

Now we come to a place where we must make a decision. If you want to grow "starts," as I plan to do, we'll need to go to another step. One Master Gardener I talked to just plants the whole sprouted potato in the ground. This allows him to start the sprouting process later, as sweet potatoes need warm soil and cannot go outside until May or even early June.

To make my own starts, though, I estimate I'll need to start the sprouting process in February. I'll also need to prepare pots for the number of plants I want from each sweet potato I have in water. As the roots form and grow, I will remove the potato from the water, cut out a bit of the sweet potato with each clump of roots, and transplant it into the prepared pots. The soil in the pots should be loose and slightly acidic. You can buy potting soil that is acidic already, or acidify it yourself by adding elemental sulfur.

Keep the planted pots in bright light, damp but not wet, and when the plants are six or eight inches tall, transplant them into the garden into 70-degree soil, spacing them about three feet apart. They use quite a lot of water, which they want constantly, so you might want to use a soaker hose, left in place all summer.

A real bonus of growing sweet potatoes is their beautiful foliage. If you can, plant them so the vines can drape over the edge of your raised bed or a rock wall. Lovely!

I will occasionally mention the progress of my experiment, and I look forward to hearing of your experience via the email address at the end of this column.

Coming up: Terry Helfrich, professional orchardist, will teach about fruit-tree pruning for the backyard orchard, from 9 a.m. to noon on Saturday, Feb. 15. The class concludes with an outdoor demonstration, so come dressed for the weather. The class will be held at the Southern Oregon Research and Extension Center, 569 Hanley Road, in Central Point. The cost is $15. Call 541-776-7371 to register.

Carol Oneal is a past president of the OSU Jackson County Master Gardeners Association. Email her at diggit1225@gmail.com.