After putting up a deer fence (a necessity in these parts!), my husband planted all the slips in the ground about two weeks ago. At the advice of a few gardening friends, we planted them right through the cardboard I'd put down to try to keep the Japanese Silvergrass and other unwanted plants from shooting back up after I did my thorough weeding earlier in the spring.
The benefits of planting through the cardboard are two-fold: the extra layer will help keep the soil warmer which makes the sweet taters happy since they're tropical vines and they like it hot, and it will also give the sweet potato vines a little competitive edge over anything else that might be in there by blocking sunlight to lemon balm, Japanese Silvergrass and weed seeds of all types.
I am hoping that, come fall, we'll have a big harvest of my two favorite kinds of sweet potatoes and a long bed of dirt that is free of Silvergrass, lemon balm and other things. Then we will just add a thick layer of mulch and compost right over top of the cardboard -- a no-till method espoused by Lee Reich, one of our gardening experts here in the Hudson Valley in his excellent book, Weedless Gardening.
I'll keep you posted! (Update - October 2014 - we harvested the plants and it was a bumper crop! Read more here.)
You might also like:
- Eat Your Weeds - Wild Garlic
- Do NOT Plant Japanese Barberry - It's a Deer Tick Magnet
- Book Review: The Dirty Life