Re houseplants: most spoiled foliage is caused by physiological issues, over/under-watering, oedema, nutritional toxicities/ deficiencies, light levels, ...... with subsequent populations of fungi acting as opportunists as opposed to acting as causal agents. In this thread, oedema, a physiological disorder, is the main actor. Dead animals don't cause vultures, but they do provide a reason for vultures to congregate. IOW, lesions caused by physiological disorder often provide the consistently moist conditions for a period lasting long enough to ensure incubation and germination of fungal spores. This isn't to say that fungal conditions do not commonly appear in plants as pioneer pathogens, only that evidence of physiological disorder is far more common than direct evidence of pioneer populations of fungi. Plant pathologists often describe the disease process using a 4-sided figure called the disease tetrahedron (think “pyramid – 3 sides + the bottom/ base”). Each side of the tetrahedron represents an essential part of the infection process. There must simultaneously be a virulent pathogen (capable of infecting the plant) that is genetically capable of recognizing its host. Either the environment must be conducive to the development of the pathogen, or the pathogen must be able to stress/weaken the plant. The 4th requirement is the time required for diseases to develop and spread. Whenever conditions are such that any one (or more) of the 4 requirements is missing from the equation, there is no immediate threat. Since the best medicines are prophylactic, the grower who makes sure plants are healthy and not stressed is ahead of the game. Biotic diseases are better able to overcome the natural defenses of plants weakened by stress that occurs when the plant is forced to deal with cultural conditions near, at, or beyond the limits the plant is genetically programmed to deal with. Al

Pretty much what Judy said! If the plant itself is already "wiggly" in the pot, just chop it off at the soil line and inspect the stem. remove leaves and cut the stem back bit by bit until there is no more brown to be seen (note, if your leaves have red backs, you will see some color, which isn't rot, but its usually easy to tell the healthy tissue from the squishy stuff once you have both in front of you.) then you can try root what is left of the crown and a bunch of leaves, IME, a lot of the leaves will look fine and then just keel over overnight. if you were ruthless enough with chopping back the crown, it should take. most of the time. I've managed to revive a standard that was cut back to 1" diameter (4 leaves), others looked better and didn't make it.... Good Luck! Karin

The white substance on your Maple leaves looks like Powdery mildew this will cause your leaves to brown,shrivel and fall off the tree......the growth on the bark is a lichen...the lichen will not hurt your tree... The photo of the other leaves, looks like they are chlorotic.... the soil is lacking iron or magnesium which makes the leaves look greener along the veins and less green on the other part of the leaf... Ian Ian

Hi Emily, I have a Eucalypt Leucoxolon which is about 4 meters tall. It has also had small brown spots on the leaves, which then die and fall off leaving the lower half of the trees branches leafless. On two sections the bark has cracked also and I am wondering if this has anything to do with the spots and die-back. The top half of the tree appears normal and is flowering though not many. My first thought was 'rust', or some type of fungus, though from looking at some sights that indicated that E. rust is not yet in this country, and the pics show the brown spots with a yellow halo - mine did not have the yellow halo, so as to whats affecting mine remains to be identified. Whilst looking up info for you, I found the following sites to be helpful, so hope they may be of some help to you. Australian Plants online http://farrer.riv.csu.edu.au/ASGAP/APOL5/mar97-4.html Association of Societies for Growing Australian Plants (ASGAP) Kangaroo Paws: Pests and Diseases http://farrer.riv.csu.edu.au/ASGAP/paws1.html Gardenweb : Australian Native Plants http://www.au.gardenweb.com/forums/oznative/ Electronic Mailbox http://farrer.csu.edu.au/ASGAP/APOL35/sep04-8.html There is also the following article which I found on the above website. Rust on gum leaves I have a 3 metre tall Corymbia "Summer Red" grafted gum that is my pride and joy. It's growing in full sun, clay soil, is staked, and flowered profusely last summer. Now it has begun to get a red rusty rash-like appearance on its leaves. I think I should cut off the lower branches, as they touch the ground, but should I then spray the tree with a fungicide? M H from New South Wales It's almost impossible to diagnose these sorts of things from a distance. The foliage discolouration could result from a range of causes, including fungal (rust) diseases, soil nutrients or lack of water. It could even just be a response to cold weather. You really need to take a sample to a reputable nursery in your area or, better still, a local NSW Agriculture office if there is one near you. If it is a rust, then spraying with a fungicide may help. You can see some photos of a eucalyptus rust in this document - this may help you decide if it is a rust problem. If it's not a fungus then probably there's not a lot you can do at this stage other than making sure it doesn't dry out. If it doesn't recover with new growth once the weather warms up, you should definitely get some local expert advice. Good Luck! ladyecheveria