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hackberry trees

Posted by burwoodbelle 6-7 (My Page) on
Sat, Oct 4, 08 at 23:47

can any one tell me whats wrong with the hackberry trees in
my yard.sticky black residue on them ,what to do.

Follow-Up Postings:

RE: hackberry trees

Cut 'em down and burn them for firewood because they aren't good for anything else. :-)

I'll take a stab at it from what I gleaned off of the Net:

Aphids are small (1/16-1/8 inch long), soft bodied insects commonly called plant lice or ant cows. Virtually every plant has at least one aphid species that attacks it. These small insects are masters of reproduction and are often found in great numbers on stems or leaves. Some species even feed on the roots of plants. They range in color from green to brown, red, black or purple. Some species may even have different color forms in the same colony. Most have the soft exoskeleton exposed, but some species produce waxy, cottony strands which cover the body. These are often called woolly aphids.

Aphids excrete a sugary liquid called honeydew. This honeydew drips onto plant foliage or other structures and provides a suitable place for black sooty molds to grow. Ants often tend or care for aphids in return for the honeydew. Therefore, if ants are running over a plant, look carefully for aphids.

Probably the most common disturbance caused by aphids is their never-ending production of honeydew. This sweet liquid drips onto plant foliage and stems and is soon covered with black sooty mold. Cars, sidewalks, and lawn furniture under trees with aphids are also covered with this sticky fluid. Ants, flies and wasps appreciate the sugary meal and can become a nuisance of their own. Even though plants may look bad from the growth of sooty molds, these fungi do not damage the plant tissues. Once the aphids disappear, the sooty mold often dries up and falls off the plant.

For most aphid problems, particularly those associated with leaf curls, insecticides that move systemically within the leaf or plant provide the best control. The most common systemic insecticide available to homeowners is Orthene (acephate). Cygon (dimethoate) also may be available as a spray for use on evergreens.

Some insecticides can be applied to the soil and taken up by the roots of the plants. These are called systemic insecticides. The most recent, Imidacloprid, is sold under the trade name Bayer Advanced Garden Tree & Shrub Killer Concentrate. (Merit is the trade name of imidacloprid used by professional tree care companies.) It is applied as a drench over the root zone. An olderand much more toxicsoil systemic insecticide that is still available for some ornamental plant uses is DiSyston (disulfoton). DiSyston is sold as granules or in plant food mixtures for soil application.

There are several insecticides effective for aphid control when sprayed on plants. Perhaps most effective are those with systemic activity that allows them to move through the plant. Acephate (Isotox, Orthene) is the most widely available systemic insecticide.

I still stand by the cut and burn method! Get rid of them and plant some nice trees!!! Come to The Middle Tennessee Plant Swap at Henry Horton State Park in Lewisburg on Saturday, October 18th! I'll have several Peach tree saplings.

Check out or website at


RE: hackberry trees

  • Posted by brandon7 6b (like 7b now) TN (My Page) on
    Sun, Oct 5, 08 at 13:21


What is this hatred you have for Celtis all about? They are attractive, relatively disease-free, drought resistant, tolerant of a variety of soils and conditions, have very strong wood/branches, extremely cold tolerant, and excellent for wildlife. If it's the seedlings you are worried about, all you have to do is mow and keep the flowerbeds mulched and weeded.

Your aphids is almost certainly correct. Your hatred hasn't completely blinded you yet. LOL

RE: hackberry trees

"They are disease-free, drought resistant, tolerant of a variety of soils and conditions, extremely cold tolerant, and excellent for wildlife."
So are a big pile of rocks or a wrecked car up on blocks but I dont want them in my yard either! :-)

Let's see, just for starters...

They are garbage trees.
They give you no Fall color.
Aesthetically they are worthless.
They CONSTANTLY drop limbs.
They grow fast but die in 40-60 years.
Their wood is weak and almost useless.
They are VERY susceptible to root fungus.
Don't forget the infestations by Jumping Plant Lice, Hackberry Aphids, Nipple Gall and Witches Broom Gall.
Because they grow quickly, they block out the sun to inhibit the growth of nice trees and shrubs that ARE worth something.

The only tree that is worse is the Box Elder.

With a plethora of nice trees available why tolerate junk? That's my story and I'm sticking to it!


I dont like the Celtics either; past or present. Never cared for Hondo, Cowens, Cousy, Nelie, Chaney, Silas, Jones, Westphal, Russell, JoJo, Heinsohn, Bird, Chief, Tiny, Maxwell, McHale, DJ, or Auerbach. I was more of a 76ers and Laker guy.

RE: hackberry trees

  • Posted by brandon7 6b (like 7b now) TN (My Page) on
    Mon, Oct 6, 08 at 10:30

Let me be the "devil's advocate" here. From my experience, Celtis occidentalis (Common Hackberry) isn't nearly as bad as the Boxelder or many other common trees.

Many people find hackberries attractive in their landscape and its yellow leaves in fall a welcome addition to the fall color palate.

Hackberry is an excellent tree for wildlife as a food source and for shelter.

The typical life expectancy of the common hackberry is actually 150 years with some living up to 200 years. Boxelders usually only live half that.

I couldn't find any source that listed hackberry as very susceptible to root rot. In fact a number of sources rated it resistant, tolerant, or even very resistant. Some sources noted that it could be attacked by Armillaria mellea (Shoestring Root Rot), but that it was uncommon and that it wasn't aggressive in the hackberry. Many other really fine trees like oaks and conifers are much more susceptible.

Hackberry wood is very useful. Here's a few quotes from the web:

- It is a good strong hardwood used a lot in furniture manufacturing. I have also seen some beautiful turnings from it. It also spalts well.

- Hackberry is one of the most, if not the most bendable wood there is. We have made curved stairs from it, cabinets, moulding and etc. It is pretty much interchangeable with ash for jobs that require staining.

- It is a very good wood. Sometimes it is called "Poor Man's oak."

- Hackberry wood is straight grained, moderately hard, strong in bending. It also possesses excellent gluing properties, holds screws and nails well, and machines well.

Hackberry wood can decay quickly once compromised. Looking for a bright side here...that just makes for easier cleanup. Instead of picking up wood for decades, you compress your cleanup time into a few years.

Like all plants, there are occasional problems with pests and disease, but compared to many other commonly used trees and shrubs, the hackberry is relatively pest and disease-free.

Don't get me wrong. I'm not nominating the Hackberry for tree of the year, but I'd rather have one of these than a Bradford Pear, a Boxelder, most Poplars, or many other types of trees. If you're looking for a tree to add to the landscape, keep searching, but if you have a hackberry, don't just chop it up for firewood.

RE: hackberry trees


I think you need to answer the question.Not
chop down all the hackberry tree.BRANDON is right
about the birds they love the berrys in the fall.
I once had a flock of 50 or more ceder waxwing in
mine at one time.

RE: hackberry trees

  • Posted by brandon7 6b (like 7b now) TN (My Page) on
    Mon, Oct 6, 08 at 22:52

Burwoodbelle, see above. Jeff thoroughly answered the question in the first reply to this thread, and (for what little it's worth) I concurred.

In rereading my first post, I realize I left out the word diagnosis. My sentence was supposed to be:
"Your aphids diagnosis is almost certainly correct."

RE: hackberry trees

Here's what appeared on Rose Forum, with my answers, from experience in TN, as to how to handle the problem.
A low tech, but effective solution

Here is a link that might be useful: With photos of the gunk

RE: hackberry trees

  • Posted by brandon7 6b (like 7b now) TN (My Page) on
    Tue, Oct 7, 08 at 14:01

:-O Ann posted a link to bug porn!

Ann, the ladybugs are great, but if the infestation is very bad (it it wasn't this thread probably wouldn't exist), it's gonna take a big swarm of them to make a dent in a tree full of aphids. Buying normal size batches of ladybugs from the various supply companies usually won't make a big difference. Within a few days, the ladybug population will likely be near what it was before the release.

Here's a link to some organic solutions. I have no idea how well many of them would work, but I'll post the link anyway. There are many similar list on the web.

Here is a link that might be useful: Organic Aphid Control Methods

RE: hackberry trees

It will take two years. Year one: infestation is digusting.
Year two: infestation is ingested.

You can't imagine the black on all of our outbuidling roofs. I could tell wind directions from where the gray was accumulating. And even the first year, I could see the glisten of a few lady bugs up in the trees starting to eat. My husband left his very ugly, very old Ford Pickup under a hackberry that year. The paint was turned from blue to a coating of ugly mold-gray. And he went through quite a few single edged razor blades to strip the c##p off of the windshield. Because it wasn't water, alcohol or bleach soluble.

I don't use insecticides, even with the monocultural rose gardens we grow. I depend on the Lady Bugs (spring version) for aphid control. And the fall ones aren't going to go away; now at least they are doing some good.

East Tennessee has this huge hackberry population. At least they give us shade and they burn fairly well in wood stoves.

Now Privet that's 25' high and horse nettle...I'm still looking for good in both.

RE: hackberry trees

"They CONSTANTLY drop limbs. "

I'm mostly with Jeff on this one. I have lived around many hackberries large and small, and in addition to their disease problems they have all shared an annoying habit of dropping limbs everywhere. My previous next door neighbor had a very large limb dropped on their CAR a couple of years ago.

I can live without them!

RE: hackberry trees

  • Posted by brandon7 6b (like 7b now) TN (My Page) on
    Wed, Oct 8, 08 at 11:19

The studies I've read generally conclude that buying ladybugs and releasing them in a small area is frequently ineffective. Some studies have shown that releasing ladybugs during certain times and/or during certain phases of their life (eggs or very young) is more likely to do some good than randomly timed releases or releases of adult ladybugs. According to what I've read, the problem with them (at least the adult ladybugs) is that even with a food source, they usually quickly migrate away from the release area; they are highly mobile.

I tried ladybugs once. I bought the maximum number recommended for my yard's area. I think it was 2 baggies full. I even splurged for the ladybug food that the company recommended to keep the bugs happy. Before I released the ones I bought, I could go out into the yard and find 1 or 2. When I released them, there were plenty of aphids in my flowerbed for the ladybugs to eat. The first day, I had ladybugs everywhere. The second day, there were noticeably fewer, but I was in hopes they were just getting distributed and hiding where I wasn't looking. As time went on, the population decreased. After about a few weeks, I was back down to 1 or 2 ladybugs visible when I walked around the yard. All the money I spend on ladybugs had absolutely no long term effect. The money and effort did nothing to get rid of my aphid problem.

The companies that sell predator bugs are not going to tell you the down side of buying from them. So, if you do decide to use this method, it might not be a bad idea to check into how to keep the bugs at home. I've never talked to the bug people over at the UT ag college about this, but I bet they could give you information on this topic. There may be a "right way" to use ladybugs that works, but there at least seems to be a "wrong way".

RE: hackberry trees

Well fed bugs have no reason to roam.

And although I've no love for hackberries, mature hackberry trees came with our house, provide shade and cooler temps in the summer and windbreaks in the winter.

If we were to cut them down, our summer utility bills would soar.
But go ahead and cut yours down, if you feel so inclined. It is a world in which we are free to do as we choose.

RE: hackberry trees

  • Posted by brandon7 6b (like 7b now) TN (My Page) on
    Wed, Oct 8, 08 at 16:56

"Well fed bugs have no reason to roam."

That's what I thought until I tried it, heard from others that had the same experience I did, and read a few studies on the subject. Apparently there may be more to it than that.

RE: hackberry trees

Can someone PLEASE, once and for all, tell me how to distinguish the Common Hackberry from the Southern Hackberry (Sugarberry). Both are common to the TN valley. All I understand is that Southern has smoother bark and smaller, smoother leaves. Do the two species also hybridize? Distinguishing is about as fun as the case with Scarlet, Southern Red, and Cherrybark oaks:(

RE: hackberry trees

  • Posted by brandon7 6b (like 7b now) TN (My Page) on
    Sun, Oct 19, 08 at 11:20

Also, C.occidentalis has serrate leaf margins, C.laevigata have mostly entire (smooth) leaf margins with only an occasional tooth or very few teeth.

From various studies about Celtis hybridization, I think it's clear that they don't hybridize nearly as rampantly as many of the oaks, but the degree to which this occurs seems uncertain. Some studies, mostly older, indicate that hybridization is common. Many newer studies indicate that hybridization is uncommon.

RE: hackberry trees

My field guides also identify a third species, commonly called the Georgia or dwarf hackberry, that is found in the TN valley. Is this the smaller multi-branched "grove-forming" specimen that I have observed in limestone barrens or was I merely observing a variation of one of the other two species? Do C. occidentalis and C. laevigata prefer different conditions? I seem to remember reading that laevigata is more tolerant of moist conditions, while occidentalis is almost entirely xeric in habitat. Am I correct?

RE: hackberry trees

  • Posted by brandon7 6b (like 7b now) TN (My Page) on
    Tue, Oct 21, 08 at 11:59

Sounds like you have everything pegged pretty well, except I wouldn't classify C.occidentalis as "almost entirely xeric". Although it occurs more frequently in upland areas, it is adaptable to a wide range of conditions including occasional flooding.

It's unlikely that the possible C.tenuifolia was laevigata. They vary considerable in multiple factors including leaf type, bark, and habitat. You could have either tenuifolia or occidentalis. Two differentiating factors between laevigata and occidentalis are leaf margins and fruit.

C.tenuifolia's leaf margin is nearly entire on the basal third of the leaf and it's fruit is orange-red when fresh and smooth when dry. C.occidentalis' leaf margins are toothed all the way to the leaf's base and it's fruit is dark purple when fresh and wrinkled when dry.

I will attach a link below to the eFloras key to the Celtis genus. I just LOVE eFloras! Maybe one day it will be complete.

Here is a link that might be useful: eFloras Key to Celtis

RE: hackberry trees

  • Posted by brandon7 6b (like 7b now) TN (My Page) on
    Tue, Oct 21, 08 at 12:54

I took a look at some Celtis herbarium leaf samples of occidentalis and tenuifolia. On average, there's a small difference in leaf margin between them, but I think it would be an unreliable indicator out in the field. Maybe if a large sample was used and averaged, there would be a noticeable difference, but it wasn't that clear to me looking at individual leaves.

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