Question
QUESTION: So if yellow leaves mean not enough water and black leaves mean too much water........what does brown leaves mean?
Thanks
Al

ANSWER: Sorry Al, brown or black leaves along the tips  too much water.  Sorry for the short info, I had to put my pooch of 17 years to sleep today and I am quite not with it.  Now I can concentrate again and this is what I found for you in Canada

 Lilac Blight (Pseudomonas)
This bacterial blight appears most often in the spring when there are fluctuations in spring temperatures, along with frosts, cold rains and poor air circulation. Lilacs growing in shaded and overcrowded locations are especially liable to attacks.
It begins with brown blotches on new leaves. Later they begin to wilt and turn black. Leaves will drop and new green shoots have a sickly dark look to them. Affected areas may turn black rapidly and resemble Fireblight. Buds and blossoms will turn black as if hit by a severe frost.
Once infection has set in, immediate pruning is of no real value if weather continues to be cold and wet. Wait until warmer weather arrives, then prune out stems at least six inches below the infected area. Cut off all dead and blackened areas, then rake and discard or burn all cuttings. Disinfect pruners in 75% rubbing alcohol or strong bleach (1 part bleach to 3 parts water) between cuts, since the disease enters the plant through wounds. If adverse weather conditions continue, avoid using high nitrogen fertilizers in the spring, spray in the fall with Microcop Fungicide or Bordeaux mixtures that contain Copper Sulfate. The blight overwinters in diseased twigs, so spray again in spring before bud break. Read and follow label directions.
A lilac that is kept properly pruned in an open shape will be less susceptible to these bacteria. Use a liquid fertilizer (10-10-10) if needed to stimulate new growth after pruning.

Hope this makes sense to you... kathy



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QUESTION: Kathy
Soo sorry for your troubles and sorry to bother you when you are soo busy.
Thanks for the info, I really appreciate it.
Al

ANSWER: Hi Al,  Thank you for your kind words, keeping busy keeps me going.  Enjoy helping others to keep their plants alive.  I hope the info helped and you are closer to solving the problem.  And with this added it still leads to too much water, like I thought.  kathy

---------- FOLLOW-UP ----------

QUESTION: Hi Kathy
We stopped watering the lilaac tree 4 days ago but now about half the leaves are brown and the normally strong flowers are turning brown as well.
Is there something else I could be doing?
Thanks
Al

Answer
Hi Al,  It could be the blight I mention above, and you would need to use a fungal spray.  Do not totally stop watering, but a good weekly watering would be necessary if it is not raining.  Did you try any of the solutions above?  There is a product called Atomic Grow that could bring your plant back to health, and it is organic.  kathy