Peonies and bermuda grass

I bought 4 peonies last year, planted them, and they didn't seem to do well; only two looked like they might make it back this year, but I had my doubts. Two looked like they had completely died back. So, since I didn't have a tiller to break the ground, and I had already hand-dug a garden patch and four other beds, and it was late in the season, I just let the grass take back over.

Well, to my surprise, they all four came back and look great. When should I transplant them, or can I dig them up, till up the bed (DH got me a tiller for spring this year!!), and then replant them without hurting their blooming potential this year, or killing them? I have also thought about relocating them to a shadier spot, as they get a lot of sun late in the season (early on they are in part sun/part shade and do ok, but then the late summer sun seems to cook them).

Or, can I round-up the grass without killing the peonies and the honeysuckle bush that is growing?

Thanks!

Firstly, if ANY Roundup gets on the peonies or the honeysuckle, it will kill them. Using a glysophate around established plants can be tricky business for that reason. Better to try to remove what grass you can by hand and then using a paintbrush, carefully paint the remaining grass with Roundup, taking care to not let it spatter on surrounding plants.

The optimum time to move them is in the fall after blooming. They have fairly large rootballs, so care should be taken to get as much of the rootball with as little damage to the roots as possible. Most peonies do well in full sun, but it is recommended in zones 7 and 8 that they get some shade during the hottest part of the day (2 to 5 pm DST)


http://www.aboutpeony.com/transplanting_peonies.shtml

http://kcgardens.kansascity.com/node/1189

There are herbicides that will kill the grass but not the peonies--two products I'm aware of are Green Light Grass Out and Ortho Grass B Gone but there are probably other brands too. The catch with them is it takes a little while before you know they're working--don't expect to go out the next day and find the grass dead. In my experience it takes a week or two before you notice anything happening, but it will work.

Here is some more info on Bermuda grass control for you, both chemical and organic.

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7453.html

http://www.sunset.com/garden/earth-friendly/how-to-remove-bermuda-grass-00400000052080/

http://www.bermuda-grass.net/getting-rid-of.html

Thanks! I guess I will just leave them where they are, and not mess with the grass, unless I get energetic and hoe it off the surface. I might try some black plastic, but I am afraid that the sun reflecting off of the black plastic will cook the peonies later this summer.

Unless you're trying to go 100% organic, there's no reason you couldn't try the grass killing products I suggested--they do work on bermuda grass and they won't kill your peonies or any other non-grass plants. Bermuda grows and spreads quickly, so if you don't do something to try and control it, it's just going to become a bigger problem. As far as the black plastic...black doesn't reflect light so you don't have to worry about that. But black does absorb heat so the soil right under the plastic could get too hot and if peonies have shallow roots it could damage them. Not to mention it doesn't allow water through which wouldn't be good for the peony either so I wouldn't recommend it.

Grassout and GrassB-Gone are both excellent products and as ecrane said, will not harm your peony. Bermuda Grass can be very hard to get rid of if allowed to get established.