Sunday, July 24, 2011

Sweet Potato - The Edible Ground Cover

     That's right, the leaves are edible too, as are the growing tips and, of course, the tubers! It's one of the easiest vegetable to grow.  As an added bonus, sweet potato foliage looks like ivy, perfect for even front- yard landscaping.
     Sweet potatoes are not related to the white potato so many of us think of when the word "potato" comes up.  That one is a member of the nightshade family and eating any part of it except the tuber can kill you.  Sweet potatoes are sometimes refered to as yams, but these two plants are also unrelated.  True sweet potatoes a longish, tapering to a point, and generally orange or yellowish is color.  The sweet potato is a spreading vine.  It will tolerate poor soil, but the tuber does best in soils of lighter texture. 
     I can't remember ever having sweet potatoes when I was a kid.  I certainly never served them at my table when my kids were young.  Now I hear that they're so nutritious that we should all be eating them every day.  So says Dr. Oz. I'm not ready to go that far, but his statement did prompt me to try a few recipes.  I found the tuber quite tasty, but Dr. Oz never mentioned the green stuff.  I learned about that from an article by Vernon Lewis in Backwoods Home Magazine (May/June 2011, Issue #129).
     But that came later, after I'd purchased three tubers this past spring and stuck them in jars, held in place with toothpicks. I'd done this before, many, many years ago, but only for the fun of seeing the greenery sprout and grow.  Those results never made it into a pot or the garden.  This time I planted the tubers, the whole things.  They looked like they were doing fine in the veggie garden.  Then my husband pointed out the article in Backwoods Home.  He suggested that my tubers were probably rotting away.  Reluctantly, figuring this was an experiment anyway, I dug them up.  Two had nearly rotted away, but the third, buried less deeply, had not.  They'd all produced healthy plants.
     The lesson here was that partially burying the tuber is one way to create slips.  So says my Master Gardener Core Manual, which I should have checked earlier.  I replanted the larger plants and cut off some smaller slips to put in a jar of water in the windowsill. 
     That's about the time that it occured to me that these vines would work great in some of my landscaping projects, so I purchased three more tubers, cut them into three or four pieces, set them in shallow containers, and am waiting for them to show green.  One source I have says to break the slips off at three to four inches and pot in potting soil (which is different from garden soil). Another says to put six to eight inch slips in a jar with water.  You need to change the water often, but you get to see the roots develop and can tell when the plant is ready to go into the garden. Another disadvantage to this option is that the roots tend to rot if you wait too long.  A week or two is all that adequate root development takes.  I expect at least a dozen slips per tuber.

Right to left: whole sweet potato, two-inch slices, in shallow pan with water, in jar with water, ready to plant.
     As for eating, the leaves and vine tips are edible any time.  Cook like spinach or use in recipes like you would spinach. Cutting the plant back keeps the foliage within whatever bounds you've set and encourages branching and fuller foiliage.  The tubers are edible even when they look like little more than thick orange roots.  For the best flavor, dig and eat when they reach five to six inches with a two-inch diameter.  They can reach a foot in length, but may be stringy.  Lewis's article has much more information and some cooking suggestions.
     I've already planted several vines in the Apple Guild and a few in the front-yard Evergreen Garden.  Both locations could use more.  Not only do they look great, but their lush foliage acts as a living mulch, overpowering most weeds.  For fuller foliage at the expense of tubers, add nitrogen to the soil. Some folks might consider it a drawback that pieces of vine or tuber left in the soil may produce another crop.  I'll reserve judgement on this; it could be a blessing in my edible landscape application.
Notes from later: The second trio of sweet potatoes I bought to grow more slips were dead when I purchased them but that is something you can't tell by looking at them. It comes from storing them under refrigeration. These are a warm weather crop and they don't do well in the cold, even after harvest.They rotted without producing slips.
     Peeling sweet potatoes is easier if you partially cook them before peeling, then finish preparing them. Our favorite recipe calls for sauteeing them in butter with a little brown sugar until tender, but they can be mashed like potatoes, baked in a variety of ways, or made into pie.


  1. Baked sweet potatoes with butter and brown sugar are so yummy that it is easy to forget that it is a vegetable!

  2. If you're looking for some really stunning sweet potato groundcover, get a couple of varieties- the range of leaf color is incredible. One thing I've been seeing more and more in my area is a mix of this amazing, electric lime green variety and a dark purple leafed variety- it's really beautiful! The shapes of the leaves are identical, so it's all playing with color.