The soil testing kits sold in garden centers are not very reliable and often do not really supply you with the information you need. I would find a good soil testing lab that was not very expensive and then use these simple soil tests for other information. Soil test for organic matter. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. For example, a good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top. 2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drainsâ too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up. 3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart. 4) Smell. What does your soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer your soil will smell. 5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy.

If you are just putting down a mulch, then just keeping it from touching woody stems and barks is OK - a couple of inches away is sufficient. Rodents bothering trees or shrubs is not a huge concern in the OP's area.....unless you are talking about mountain beavers and nothing short of a wire cage surrounding the plant, including roots, will keep them away. The intent is to keep a moisture holding material - like most mulches - away from the woody portions, as it can contribute to rot and bark damage. It won't 'leach' nutrients out of the tree. If you are spreading compost to provide a nutrient source, then yes, you do want to extend that covering out to the dripline, at least. That's where the bulk of the feeder root are located so that's where it will provide the greatest benefit. FWIW, very few tree species develop tap roots and even many of those that do, do so only when very young. The tap root disappears with maturity. Most tree roots are contained within the top 15-18 inches of the soil and many are located just below the soil surface. Neither compost or any other mulch should be applied too deeply - 2-3 inches is sufficient. And somewhat less for very shallow rooted shrubs like rhodies and azaleas. Too thick a mulch layer can smother the fine roots located at the soil surface, depriving them of oxygen.

That is definitely Campsis. And the behavior you describe is classic - cutting it back to the ground or even digging up the main rootball does not guarantee its removal. It can regrow from root shoots located at considerable distance from the original plant and they spring up very rampantly and aggressively and can persist in doing this for years before the thing finally loses strength and gives up.

Steve, the challenge with this situation is that your pre-emergent needs to reach the soil surface at a certain rate of application. The chemical needs to be watered in properly in order that the solids can liquify, enter the soil, and form a temperary barrier against germinating seeds. Applying the granules over the juniper and hoping that it gets to the soil in a relatively even layer is not the best use of Preen. There are other options, but I would first need to know what kind of weeds you're battling with. For example, I have a dense growth of beautiful Parsoni juniper in our front beds. Few weeds are able to infiltrate but we always end up with a crop of nutgrass and a few broad leaf weeds. We are able to spray a mist of herbicide that kills grassy weeds but we pull the broadleaf weeds. Preen (or similar) is not an option.