Question
Dear Jim,
My Debra Maple in Colorado is getting odd brown areas along the veining on the leaves. Then this brown part crumbles up on the leaf and the brown part dies. Some of it is in an odd pattern. It's in the lower 1/2 of the center of the leaf and then extends some beyond the center towards the left and right side of the leaf. It's fairly symmetrical in many of the leaves.  I had a tree person out and they said it needed water but I don't think that's it.
Could you please let me know what you think is wrong and what I can do. Your help greatly appreciated. Thanks

Answer
Sounds like Maple anthracnose. The most common symptoms include brownish discoloration along veins, varying from discrete spots to irregular patches of discoloration bordered by veins. Spore masses of the fungus can sometimes be found on lower leaf surfaces along veins during extended moist conditions. The fungus spreads from previously infected tissue in spring to new growth. Maple anthracnose can be distinguished from leaf scorch by the presence of spore producing organisms, resembling ground pepper, on the undersides of leaves.

Anthracnose, caused by Discula spp., is a common springtime problem on maple. Red to black spots or blotches form on leaves, particularly during wet, cool spring weather. Typically, the spots are formed on or near leaf veins and progress along the veins towards the petiole or stem. The disease also may cause twisting, crinkling, or other leaf malformations. Premature defoliation resulting from anthracnose is common in some years, although the disease does not kill the trees or cause permanent damage.

The good news is this disease usually does not kill the tree. Here rae some treatment that will reduce the impact of the disease.
旼ather fallen leaves before the trees leaf-out in the spring and either discard or compost.
旻ertilize and irrigate trees that have suffered considerable foliar blighting and defoliation. Use 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter scattered around the tree and watered in good. Apply this Fall and again in the spring.  
旳pply fungicide on newly planted or small specimen trees such as Japanese maple previously damaged by anthracnose. Fungicide treatments can give effective disease control. For best results, make the first application as the trees begin to leaf-out in early spring. Additional sprays should be applied at 10- to 14-day intervals until the new leaves mature. On maple and oak, bordeaux mixture, Daconil 2787 4F, Daconil Ultrex, Dithane T/O, Fore, Protect T/O, 3336 50W, 3336 4.5F, and Halt are among the fungicides labeled for control of anthracnose. Always refer to the label for use rates, directions, and precautions before applying any fungicide.