You have deciduous azaleas that bloom in August?????? What are they????? I know prunifolium blooms late in the season, but that is very late. I haven't seen the problem you describe. Some leaf spots are caused by a virus thought to be a potexvirus, the most common ailment being called Necrotic Ring Spot. The symptoms are reddish-brown rings or spots on the leaves. It generally occurs only on the two year leaves of a few rhododendron cultivars such as R. 'Unique', or on Kalmia latifolia. It also appears on the first year foliage of some R. 'Loderi' clones. Little is known about the disease and a does not seem to spread from one cultivar to another. No control is known or generally necessary. Small bright yellow spots is a symptom of Azalea Rust, Puccininastrum vaccinii, a fungal disease. Orange-red pustules containing spores form on the lower surface of the leaf. This rust is only sporadically severe and typically infects deciduous azaleas. Control by avoiding those hybrids and species which are very susceptible to rust. Good air circulation is helpful. Triadimefon seems to help, but may not be registered for use on rhododendrons.

Please notice that the leaves are drying from the edges inward. This is not a fungal leaf spot. (Yes, I know the previous post didn't refer to that portion of the leaves -- I'm just trying to clarify the problem at hand.) Beyond that, the spots we do see on the leaves -- inward from the dry zone -- don't fit the requirements for a fungal leaf spot. For this tree, nothing will remain if one follows the suggestion to "Remove twigs, leaves ... and destroy them." Further, the bare twiggy ends at the top of the tree are likely drying back and/or already dead. (This should be verified by scraping the surface of the branch tips -- alive and creamy? or dead and gray or brown?) That those branch tips in the upper portion of the tree are bare/dead is a cue that a root problem exists. It's worth checking the soil's moisture content. Further, this tree is receiving lots or reflected light and heat from its suroundings, all of which increases its need for water. Thus 15 minutes of sprinkler irrigation 3 times a week is likely to be far too little. This is especially true if the tree is in a warm, or hot, and/or dry climate. Another consideration is the soil -- what kind; how deep; and what sort of drainage. Perhaps the tree is drowning.

Here's another advantage of whole-grain corn meal: ants and insects can't digest that stuff, thus decline. I buy 10 lbs. bag of cracked corn for $2.69 from the feed store, and grind them with a Nutri-mill flour-grinder. Awesome as a fertilizer, buds everywhere, fast result like alfalfa tea, but with more buds. NPK of whole-grain corn meal is 1.65/ 0.65 / 0.4 ... that's much better than horse manure with bedding, at NPK of 0.7 / 0.3 / 0.6, plus salt. pH of cracked corn is VERY ACIDIC at 3.5, thus neutralize my alkaline tap water at 8.3. I checked on fish bone meal, that stuff is so stinky that a person reported the neighbor couldn't sleep with its application. Both fish meal and fish bone meal attract huge black flies. I tested the refined corn-meal from Walmart ... it was worthless, no nutritious fatty germ layer, just junk-food that attracted flies, and didn't work as fertilizer nor fungicide. Some feed store grind the cracked corn into meal for a surcharge. Grubs are the larvae that hatch into Japanese Beetles. Here's an excerpt from Soil Forum â¢Posted by digdirt 6 -7 AR on Sat, Mar 15, 08 at 13:18 Corn meal also an effective control for grubs and cutworms - they love it but can't digest it, so they eat and die. I'd add it straight to the garden as well assuming we aren't talking a tiny little garden for that 25 lbs. ;) Dave This post was edited by Strawberryhill on Mon, Jul 21, 14 at 14:50

Re-posting what I posted on the other thread: Folks report that Azomite helps to deter pests, it thickens the tissue of plants. Molasses work very well in deepening the blooms' color, but I'm afraid to use it, for fear that would attract pests like rose-slugs. When to use gypsum (calcium sulfate) and when to use dolomitic lime (calcium & magnesium) ? I narrow down to: If the rose blooms profusely, means it's good in acid-phosphatase, and will have excess acid at end-bloom-period. Time for dolomitic lime during profuse-blooming. If the rose is stingy, means it doesn't secrete enough acid to release phosphorus from soil. Time for SOLUBLE gypsum (calcium sulfate, with 17% sulfur). The acid, or sulfur helps to release phosphorus from soil for blooming. The mycorrhyzal fungi that help plants to bloom also prefer slightly acidic. Some disease-resistant roses fall into this category (Home Run, Basyes Blueberry, Duchess de Rohan, some Kordes roses). Folks in alkaline CA complain about Kordes being huge & healthy foliage, but stingy in blooms. Never see a black spot on B.B, but it's stingy unless given soluble fertilizer. Home Run is filled with dark-green foliage, but few blooms. I would rather get the disease-resistance from thick & shiny foliage (FlowerCarpet), than stinginess in blooms (Home Run). If the rose is wimpy, SOLUBLE gypsum and sulfate of potash help. Buffers are alkaline stuff put on top to neutralize acidic rain. Horticultural sites listed calcium, potassium, magnesium, slow-released organic matter as good buffers. Alfalfa hay is a good buffer (neutral pH, slow-to-break down), same with pine-needles. But alfalfa meal is a poor buffer: breaks down too fast, and releases acids. Cedar-mulch is a good buffer (slow-to-break-down). Pine bark mulch is a poor buffer (acidic pH at 4). Penn State research on artillery fungus cited BIG CHUNKS & SLOW-TO-BREAK down mulch as best. Red-lava-rock is an excellent buffer (pH 8) & slow to break down. I spent $10 on a tiny bag of crushed-red-lava-rock, ordered from Amazon, and it WASN'T AS GOOD as the cheap $4 per 40 lb. bag big chunks. The crushed-red-lava broke down too fast, and stained the leaves of Stephen big Purple with its high iron-content. In contrast, I get continuous blooming on Wise Portia this year thanks to big-chunks red-lava-on top (for potassium), plus dolomitic lime (calcium & magnesium) .. lots of leaves thanks to neutral alfalfa hay on top. Nature's way is best: For centuries big-chunks stuff fall onto roses or occur naturally in soil: leaves, branches, rocks, etc.. Centuries ago, people didn't have wood-chipper to grind bark into pieces, or trucks to carry inappropriate mulch (pine-bark) onto roses. Chicago Botanical Garden made a good point of mulching plant WITH THE SAME optimal pH range for that plant. So it doesn't make sense to mulch Dr. Huey-rootstock with acidic pine (pH 4), or to mulch blueberries with horse manure (pH over 8, with lime added).