Have you pruned it recently? Mesquites (and most other trees) will put out sap in order to seal off wounds (like if you cut a branch off). If the sap is clear and healthy looking, not black and nasty, I would not worry... but still keep an eye on it, it should stop after the wound is healed.

The black sap is just some bacterial baddies working it's way out from a wound area. The tree usually makes it out just fine and it's not uncommon, especially in areas with high wind. You can sometimes see the black sap splattered like tar on understory plants.

If you prune wait until the heat is kicking because it lessens the chance of the "black sap."

They also tend to sap up when they're breaking dormancy and going into their growing season.

Black sap from a "V" or branch crotch could be a sign of included bark. Mesquites are notorious for forming close branch attachments (less than 45 degrees), and instead of the bark being pushed up creating a ridge it folds under into the "V". This indicates an area of weak attachment and also where bacteria that create diseases like Slime Flux can weaken the wood.

Left alone, this weak union will usually fail and often causes huge wounds and ripping bark. If this is the case it is probably a good idea to remove one the branches.

Mesquites often drip sap from pruning wounds and this is pretty normal.

If you decide to do any pruning, don't use sealants on the wound. They trap bacteria and fungi inside creating more problems. Just leave the wound open to the air and if you have made the cut at the right location, the tree will heal itself.

Here is a link that might be useful: Pruning Planting and Care

I had two trees with dripping sap - one tree looked like it was headed for the great beyond. I went to one of the large box stores to ask about it and the guy told me to immediately call an arborist to come out and deal with the really bad bugs that he swore were going to kill my trees.

I had a vision of hundred-dollar bills floating out of my wallet so I went to my friendly neighborhood nursery (that specializes in native plants - and where I should have gone to at the beginning!) and the guy there said exactly what aztreelvr and nc-crn said.

I left both trees alone and both are thriving - and my wallet is much happier!!!

Hi,

I've relocated to AZ after about 20 years back east. Was an ACN here way back when. The house I purchased here was vacant for about 2 years and had 4 overgrown Mesquites in the front. All of them I trimmed last fall shortly after moving in.
One of them has been and continues to drip a lot of sap. I really just thought it was related to much of the above description in regard to the trimming. However, upon closer examination it's coming from many places. It's mostly clear and is quite a large blob where it was dripping. Knocking off a sap blob will cause fresh sap to come out. Otherwise all of the trees appear healthy. Just had them trimmed and thinned and the guy that did it (seemed well experienced and knowledgeable) had no idea why this one was doing it and why it was coming from where it was coming. Any ideas? I'd like to share a pic but can't seem to add it here.
Thx!

Kmacn - Mesquites do that. Stop picking the scab off and let it heal. Also, if you can. decrease the water it gets.

The "gum" they are exuding will dry to a clear, crystalline mass that smells wonderful when you burn it. This fall, try knocking some of the dry stuff off and toss it on a BBQ.

Or leave it for a thousand or so years so someone can make jewelry out of it >smileI'm glad this thread was revived, I had the exact same question about my mesquite.

I have two mature Mesquites (30 yrs) and noticed green leaves dropping which have black spots on the underside and sappy stems. I also noticed a tiny black beetle crawling out of one leaf. The lower limbs appear brown and very thin vegetation. Any idea what is going on with them? Thanks.

piperflyer - What you report is typical for mesquite at this time of year.

They shed a bunch of leaves in the late fall, and if it gets too cold, will shed the rest of them.

They also die off at the bottom, putting most of their energy into branches with better sun exposure. . Look at a wild mesquite and half or more of the lower and inner branches are dead.

The "sappy stems" may be because you are overwatering. If they are 30 years old, they don't need supplemental watering.

I HAVE A 8-9 YEAR OLD TREE THAT HAS SAP COMING OUT OF IT ALL OVER IT TREE IS NOT DOING WELL SEEMS TO BE DYEING SAP IS DARK YELLOW COMING OUT AII OVER ON LIMBS NOT VERY FULL THIS YEAR SAPPING IS RAMPID ALL OVER AND DRIPPING HELP !!!!!!!!!

Marc -

This could be part of the normal sap flow in the tree which kicks into gear this time of year. If the tree is growing at a fast pace, possibly from receiving too much water, the weak areas in the tissues can split (microscopic to several inches in length) and fluids can escape. This flow of sap can also be from stress such as from pruning or wind damage. A tree's vascular system is under pressure so if the tree is stressed it can also ooze sap. It wouldn't be unusual for insects to be attracted to the or sap, especially June beetles and bees. They won't harm the tree - just looking for an easy meal. It would help if you could post a photo.

have 6 mesquite on property in 29 palms ca. 4 grown from seed. they were pruned heavily last year which I think makes them vulnerable to pests both insect and bacterial. one tree started oozing globs of golden sap maybe 6 months ago. I thought it was an insect (bore). that tree had a dead branch last month and the tree is now dead. now I see an adjoining mesquite has dead branches.

You are correct that heavy pruning will weaken a trees' defense mechanisms, making them more vulnerable to pests and diseases. Remember that every green leaf is a food factors for the tree and when they are removed you basically starve the tree. On top of that it's possible that the branches and trunk were sunburned after the foliage was removed. A tree with damaged tissue actually emits chemical signals that attract pests, like borers. For now be sure to deep water your remaining trees once every 2 - 3 weeks. If they were also pruned, you can wrap the trunk loosely with burlap, cardboard, or fabric to prevent further sunburn. The rule of pruning is to never remove more than 25 percent of the living parts (leaves, stems, branches, etc.,) in any year. Don't use sealants on the pruning wounds. A good resource is Pruning, Planting and Care by Eric Johnson, Ironwood Press. Good luck.

how do you remove the sap from stone?

Scrub with soapy water if its fresh. it's water soluble

Hello, I bought property in South Texas and have alot of mesquite trees. I thin them out because they were many together. I now notice the bottom of the trunk turning black. Are my trees dying. I also notice lots of sand roads from termites. Help