Jellyman & harvestman are onto it. I've been killing black walnuts on my farm for the last two years. Not a lot of them but perhaps two dozen...alongwith hackberrys, box alders,and ashes. If there is a misshapen BW near where I want to put an apple....the BW dies. I have used both methods mentioned....girdling & boring (and a third, 'hack & squirt' ... opening up the bark with a hatchet and squirting in a herbicide.) I've only used 41% Round-Up undiluted. It will kill the tree within a month. For me I use a 3/8" drill bit and drilled holes, one on each side.....downward angle for about 2 1/2 to 3"...then filled the hole with the 41%RU. Crossbow & Garlon are effective also, however, I have not used them. I've done this in July and it kills the tree. Girdling will kill the tree, but slower...it may take a year to die. I think given your sense of diplomacy with the neighbors the drill method would suit you just fine. There are lengthy discussions on killing big trees in the 'Habitat' forums on the website for QDMA. Quality Deer Management Association www.QDMA.com

I wouldn't call Sissoo tree roots invasive - aggressive, yes. That's one reason why they can take our harsh climate and alkaline soils. Roots will go where water is available which is why watering deeply (to three feet) is so important for trees. You may notice that trees planted in lawn areas frequently have roots at or just above the soil surface. That's because grass receives shallow watering so naturally more tree roots will be in that zone. The feeder roots from trees will spread laterally in a wide area and will be located in the top two feet of soil near the drip line of the tree and beyond which is why drip emitters should be placed at the drip line. Anchoring roots will be located much deeper. Here's a link to planting tips that will get your new tree off to a good start. You may be interested in the FREE landscape workshops that the Town of Gilbert has starting next month. Take a look at the water conservation web page (www.ci.gilbert.az.us/water) on the Town web site or call 480-503-6098. Here is a link that might be useful: Planting trees and shrubs

Best way--and hardest work--is to just keep pulling the bermuda grass out. Water well, then start pulling when the soil firms and water has soaked in a bit. There are a number of herbicides that target grasses, however few of them have labels for flower beds. In some cases, the grass herbicides will also have some activity against certain broadleaves, so if you go off-label and just try something, you might get a few of your flowers as well. You might look at Preen in a small area as it is recommended for grasses, but don't know what it may do to the plants you want.

Diatomaceous Earth will kill all kinds of bugs and is perfectly safe for humans and pets. It is also called fossil flour. We used to use it for the chickens to kill mites - put piles of it around for dusting beds. We use it for ants (can even sprinkle it on counter tops). Works for roaches and bedbugs but fortunately haven't had to test it for those. Also good for pets - ear mites and fleas/ticks. Can be given in pet food for internal pests such as worms. Buy only 'food grade DE', not the stuff they sell for pools.