Summer is when cypress family conifers discard the old foliage. There may be no direct connection between the dead leaves and the sap.

what he said.. restated..

no conifer.. holds it needles forever.. most shedding them within 1 to 3 years ... interior needles are the oldest.. and are the ones shed.. on schedule..

the fact that all your pix.. refer to the oldest needles.. attached to the trunk.. are proof ...

it is when the youngest needles.. the growth tips.. lets call them.. start browning.. that you have trouble..

all that said.. these plants have a multitude of problems... of which i have no experience .... because they really dont like MI.... lol ...

but bboy is in the center of it all.. and if he says.. normal interior leaf shedding.. then ....what he said..

ken

Thank you very much for the help - it makes a lot more sense now why all the trees are exhibiting the same phenomenon.

why all the trees are exhibiting the same phenomenon.

===>> exactly ...

you were afraid it was personal .. lol.. to your tree ... and that MIGHT be an issue..

but when i have a problem.. the first thing i do.. is start scoping the neighborhood.. to see if it isnt some general problems.. which means one of 2 things

1-- its normal.. as this case

2-- its not normal.. but its a general plague.. and there is little you can do anyway.. since you cant treat all the trees int eh area ...

this plant will still have problems over the years.. learn about them now.. so you will be prepared .. emotionally.. when real problems start..

ken

I notice there is fencing and walls nearby. If you did not know already be forewarned that this produces a full-sized tree growing well over 60' tall, with specimens in the Seattle area already having developed average crown spreads of more than 40'.

bboy: Yeah, I have already been warned (by you in fact) a while ago. I am going to maintain these trees as a hedge - ie trimming them once or twice a year.

Here's a blurb from our local extension service in NC.

"Seiridium Canker

Seiridium canker, caused by Seiridium unicorne, is probably the most damaging disease on Leyland cypress. Plants of all sizes and ages are affected. Cankers may form on stems, branches and in branch axils causing twig, branch or, at least on smaller plants, stem dieback. Cankers appear as sunken, dark brown or purplish patches on the bark, often accompanied by extensive resin flow. It should be noted that resin exudation often occurs from the branches and stems of otherwise healthy plants of Leyland cypress thus resin flow by itself is not a diagnostic characteristic for Seiridium canker. Scattered twigs or branches killed by the fungus turn bright reddish brown, and are in striking contrast to the dark green healthy foliage. Fruiting bodies of the fungus appear on the bark surface of the cankers as small circular black dots barely visible to the naked eye. Spores of the fungus are spread to other parts of an infected tree, or from tree to tree by water splash from rain or irrigation. The fungus also can be spread from tree to tree on pruning tools. Long distance spread appears to be through the transport of infected cuttings or plants.

Currently there are no chemical control measures recommended for the disease in the landscape or nursery. Avoiding water stress and tree wounding may reduce infection. Infected branches or twigs should be pruned and destroyed as soon as symptoms are noted. Prune at least one inch below the canker, and sterilize the pruning tools between cuts by dipping them in rubbing alcohol or in a solution of 1 part chlorine bleach to 9 parts water. Tools should be cleaned and oiled after using bleach to prevent rusting. Severely affected plants should be removed and destroyed."

Here is a link that might be useful: Please click for all the other leyland diseases

The trimming should have started quite some time ago.
Mike

Yes.