Bermuda is best killed when storing energy that early September in my zone with roundup sprayed on plant that time year 100% kill of plant, but their seed for next year crop so September again following year. Take me about three years and gone.
Spraying other times year kill 80 90 % it come back thin. I don't no right time for your zone my zone 8b.

I use Grass B Gone (0.48% Fluazifop-P-Butyl), but it's still important not to get it on the trees. If there is a chance a tiny bit might get on them, I figure this product is safer for the health of the plant that way, in any case. It's not designed to be used with edible crops, though.

Edit: I use it around the trees only. It's more expensive than the total-kill products! ;)

This post was edited by meredith_e on Sat, Jul 6, 13 at 18:22

How big is the orchard? I have Bermuda grass for my front lawn and when it gets into my planters I pull it and use a weed eater. Is the orchard something you can mow? If you cut it really low it may work to kill it without herbicides. Keep in mind that Bermuda grass is pretty tough. Is it possible to use the Bermuda to your advantage? It requires very little water and would likely keep the moisture in the soil. It's also easy to manicure.

There are selective grass killers that don't harm broadleaf plants. I've used them around my trees. Around here the only Bermuda that holds moisture in the soil is dead Bermuda after being sprayed. When green it's deep rooted and sucks the soil dry.

It's on A terraced hillsid, and its choking my new fruit trees. Can't mow it, and pulling by hand has proven futile. I will try a grass selective herb.

Use a weed/grass control such as weed-be-gone and follow the instructions on the container. Apply it on a non-windy day by holding the nozzle low so that it only covers the bermuda and does not spray onto your trees. Immediately around the trees use a hoe and dig the bermuda out to a distance of about 1 foot. It is good for a few months and then will need another application. After a few applications it will stay gone unless nearby bermuda seeds blow onto your orchard.