Sweet Potato slips have arrived...how to protect from voles

This will be my third year planting sweet potatoes. The first two years I lost a good number of sweet potatoes to voles. I am having trouble deciding what to do different this year to improve my yield, and now that my slips have arrived I have to make a decision. I thought I'd post to this forum, to see if I can get some advice.

I have a couple of large 18" diameter, 15" deep pots that I might plant some of the slips in. Based on what I've read on the web, I've come up with some thoughts on what to do. 1) Just plant the slips in the pot, either 2 or 3 slips to a pot (undecided on how many) and call it good. Or, 2) Cut out the bottom of the pot before planting. I think this may help in making sure that the sweet potatoes are kept moist - as the enclosed pot may lead to the soil drying out quickly. But, if the bottom is cut out, the voles may go up through the bottom of the pot. So to deal with that problem, I thought I might bury the pot, but how deep do I need to bury it to keep the voles from getting into it? Or do I need to bury them at all - would the pots just sitting on top of the ground be discouragement enough? Or, if I bury the pot, should I put hardware cloth over the bottom of the pot before I bury it? I'd rather not go to this trouble and expense if I don't have to, so I'm looking for anyone who has experience in this.

In either the above scenarios, do I need to also cover the top of the pot with hardware cloth or plastic to keep the voles from climbing into the pots - how high off the ground do they need to be to not have to cover the pot? I'm thinking 15" is high enough, but if I bury the pots, I would want to be sure that the top of the pot isn't too close to the ground, or that it is protected on top to keep the voles out.

Then, aside from the above, I have a question about the vines. My experience is that the vines may anchor themselves down in the soil as the spread out, but they've never produced any roots with sweet potatoes from the vine. Is this normal? Some people seem to think that if you cover the vines with soil, that they will produce sweet potatoes, but from what I've read, everyone that has tried this has talked about being disappointed with the result.

I've also read that the vine and flowers are edible. I'm think about placing the pots next to a fence for the vine to climb, and then harvesting leaves and flowers from the vine to eat. So, another question I have is how much of the vine and flowers can I eat, without affecting the growth of the sweet potato under the ground?

Thanks everyone for any suggestions you can offer!

If the bottom of the pot is open, it is open to voles. We have been planting in heavy duty trash bags and have had very good success with it. Here is some info...most talks of white potatoes, but it has worked well for sweet potatoes also.

http://www.ehow.com/how_7404666_plant-potatoes-garbage-bags.html

http://urbangardencasual.com/2008/04/30/growing-potatoes-in-a-small-garden/

some anecdotal info:
http://forums2.gardenweb.com/forums/load/contain/msg0614520324855.html

You might try planting chrysanthemums around them. I noticed this spring (when cleaning out my garden beds ... which were half destroyed by voles or moles this winter ...) that the chrysanthemums and daisies had not been bothered at all, though the irises and columbines planted right next to them had been eaten, among others. I did some research and found (at this URL http://forums.gardenweb.com/forums/load/neweng/msg1000002111737.html) a posting stating that

"nhbabs brings up an interesting point; that she hasn't had a problem with chrysanthemum roots being eaten by pests. Pyrethrins are a natural insecticide produced by some chrysanthemum flowers and pyrethroids are included in many commercially available insecticides. There are some claims that pyrethroids are irritating or harmful to humans if misused, and it could be that critters avoid the roots as being poisonous. This makes me wonder if chrysanthemums could be judiciously planted to deter voles and chipmunks. Just a thought"

I thought the info about PYRETHRINS being in chrysanthemums was interesting.....

Another posting on the same website said:

"there are winter hardy chrysanthemums that come back every year. I have three kinds: a copper colored very double one that is blooming now right through heavy frosts and freezes, a pink daisy-like one that bloomed about a month ago, and a white daisy-like one that is low-growing called C. weyrichii 'White Bomb' that makes a good groundcover. All spread to one degree or another, mostly more rather than less. I've never had a problem with any of them getting their roots eaten, even in beds with many mice/vole/chipmunk tunnels. They have a rather strong odor, and this may be a discouragement to those that would eat them, or it may just be that they grow faster then they get eaten." and "By the way, moles aren't ever a direct problem with your plants as they eat insects, grubs, and worms. Their tunnels may be used by mice, however, who will eat plants. Voles are shallow tunnelers who eat plants, and in the winter can be quite destructive to plant roots."

... both statements were interesting to me.

Just thought I might share the info I found with you. Hope it helps.