I have a number of thriving crabapples (one a profusion) and apple trees on my property. Apples love it here in Vermont so they usually do very well. However one tree that I purchased, I think it was an American spirit, developed apple scab. I suspect it had been ill treated before I purchased it, and the stress of transplanting was a final blow. I purchased a fungicide, captan, from this place: http://www.treehelp.com/captan-fungicide-8oz/ I mixed it per the package directions and either sprayed it on the leaves or dabbed it on, can't remember. Fortunately the tree was small so I was able to apply it to nearly every leaf. It worked like a miracle. About a year later we had a new waterline installed, and I had to dig up the tree and move it to a different location to prevent the roots from growing into the line. I feared that a second transplanting would be the final nail in the coffin, but my crabapple had recovered to a point where it survived the transplanting without a single wilted leaf. It has tripled in size in the intervening years and is very healthy. This seems remarkable to me considering that during the final transplant I had to slice through a number of roots and even the lower section of the taproot. I guess my whole point is that captan works wonders on apple scab and I would give it a try sooner rather than later. Also, my experience is that you cannot overwater an apple tree. Many of mine thrive in extremely wet areas. They also grow in drier spots, but I wouldn't worry about excess moisture. I had planted a lilac in one wet spot, and it was gradually dying. I moved it to a drier area and planted an apple tree in its place. Both are happy with the arrangement. The lilac came back from the brink of death and the apple is thriving in the "lilac death spot." My profusion tree is the one in the center, and the tree on the right is the former apple scab invalid. Photo is from a few years ago.

Lower leaves are the oldest leaves and will drop for any number of reasons but in heat and water stress, roses will sacrifice old growth for new. An annual dropping of leaves isn't uncommon as we enter a period of natural dormancy or significant weather changes that impact uptake or availability of nutrients to the plant. Increasing the water during periods of heat and drought will limit the leaf-drop but also erecting some type of shade structure will limit it substantially as the intensity of the sunlight and heat is reduced. Limiting or reducing fertilizer applications during extremely hot weather will curtail some new growth and not stress the bush as much. Keep in mind that when leaves turn yellow and fall in a forest, we call it Autumn and expect the trees to go dormant as winter moves in. Some roses react the same way as they sense changes in humidity and temperature. In this area, we do a light pruning to remove summer growth and encourage new growth and fall blooms then do a hard-pruning in January. At that time, we remove all leaves anyway. I believe blackspot is a tough disease for arid climates to have, especially when the average daily temperatures are over 90F and humidity less than 15%. Phoenix even saw a couple days where humidity was less than 0% this summer.

I alternate between a couple of them; always with added vinegar due to my irrigation water pH of 9+. Most often it is Liquid Gold (Master Nursery/EBStone) [15-6-3] Then, Foliage Pro [9-3-6] And lastly once every 2 months (and because i bought a bunch of it years ago-cheap) Miracle Grow - very weak solution. this is not a cheap method, but its the only way i have found to feed the citrus during the heat season and keep it growing without using excessive water. [there are improvements and changes that i need to make to the irrigation, but unable to attack that project at this time. So i am stuck with what i have for now]. I used to mix it all in a watering can and apply to pre-wet soil. I mixed for a 1 gallon amount, but in a full 1.5 gallon can (so a bit weaker solution). 1 can per tree (or more if taller than 6ft.). Today i tried a sprayer and believe it worked well. I used a Hudson hand-held sprayer that has a metering knob. I could turn the liquid addition off, and then adjust up to 1 Tbsp /gal. This turned out to be a much faster and more convenient method (45 citrus trees) so i think i will stick with it. -George

I'm having the same problem with overwatering being the likely cause. It has rained here nearly every day since May and one of my potted figs has basically said enough. I drilled a couple more holes into the pot and have added a wick to help pull away some of the excess moisture, but I'm going to have to wait and see how it goes. I repotted many of my figs into a more easily draining mixture, but I figured I'd leave the three largest alone (as I had repotted them last summer) but I never considered I'd see as much rain as we've had this spring/summer. ~Chills