What sort of "awful" comments have you seen? Mimosa, Albizia julibrissin, is a nice small tree. It will need to be shaped but I don't know that it needs heavy pruning.

Judy if you go to the tree website, Mimosa is written up as being a noxious weed.

I know that in the southeast USA it's very obnoxious, but I'm not aware of that problem in the desert. I suppose it's possible in riparian areas. I haven't been to read the tree forum yet, but I will.

Well phooey on the tree website then! *grin* I like mimosa trees and think that they are lovely when they bloom, smell wonderful and the hummers absolutely love them. I lost the one I had for 16 years to a beetle of some sort, but am currently growing 2 from seed. They are about 15" high and doing very well! I obtained the seeds from my father-in-law and he has the tree in Dewey AZ. It was covered in snow that day, so it can take the cold quite well. The next time I saw it was in May and it was blooming like crazy!

I only did small shaping/trimming to obtain the look I wanted. It had a nice shape and I simply encouraged it. No need to do much pruning at all.

Susie

I skimmed the Tree forum about mimosa. They do have a point about its ubiquitousness in the SE but that's a totally different environment than AZ. My mother had one in Clarkdale, it tolerated the heat and cold, but as far as I know, didn't spread into the Verde area. Just not the right environment, I suppose.

The Mimosa is a lovely tree and needs only minimal pruning when young to develop the main scaffolding branches that will produce a nicely shaped tree at maturity. Do not prune anything off your new tree until it has been in the ground at least a year (except dead or broken branches). Remember to never remove more than 25 percent of the foliage/branches in any year and your tree should be fine. Don't prune in the summer months when there is a risk of sunburn to the trunk and branches.

Mimosa trees can be a bit marginal here in the low desert. They really like to grow where it's a bit cooler like Globe or Prescott. Because our brutal summer heat can be stressful on these trees they can become vulnerable to damage from the flatheaded borer. The larvae from this metallic colored beetle feed on stressed or dying wood (not live, healthy tissue). This could be what happened to Birdlady's tree? I had one growing in flood irrigation that only lasted about 8 years before it gave up.

Here is a link to a bit of information on pruning.

Here is a link that might be useful: Pruning

I love my Mimosa too. Wonderful fragrance all summer long, attracts the hummers and butterflies. I recommend putting it in a lawn area or someplace where you don't have gatherings often. They can be a bit messy with the flower clutter. Other than that, a fine tree. Hopefully my two Chocolate Mimosa seedlings will make it through the freezing cold. I put them up against the house too. They have tended to go somewhat burgundy on me over the summer in partial sun, but have been afraid to put the seedlings in full sun. If they are true to their parents, they will be a stunning burgundy once planted in full sun. Keep your fingers crossed! :)

Easy

I see there have been no posts for mimosa trees in AZ since 2005. I have three trees near phoenix and love them.
Last december I found I had flat head borers attacking it
So I have been treating them since then. No one seems to know much about them around here or what to treat them with.
I think I have gotten the worm. Any help out there would be appreciated.
sarah

Flatheaded borers are attracted to stressed trees and tunnel into dead or dying parts of the plant. The female lays her eggs in the stressed tissue and the young larvae move into the tissue, munching as they grow. They create tunnels just under the bark layer and produce 'frass', a sawdust like substance. Basically, its digested wood.

The larvae live in the tree for a year or so and then exit as adult beetles. Elliptical shaped holes in the trunk and branches will show you where the adult exited the tree. The adult beetle has a green or tan metallic coloring to its body and may blend in well with the color of the bark.

Because the larvae of the beetle lives in dead wood, there is no effective treatment. Prevention includes keeping your trees as healthy as possible to prevent stress. Stressed trees give off chemical signals that attract the beetles. A great example are the pine trees in northern Arizona. The trees were stressed because of the drought and competition for water. The bark beetles moved in because the trees were stressed. (This is not the same beetle that affects your mimosa.)

Stresses can be due to water (too little or too much), over pruning, sunburn, over fertilizing, chemicals, construction in the area which can damage roots (trenching, compaction) and storm damage.

Here is more information on the flatheaded borers.

Here is a link that might be useful: Flat headed borer

Am trying to figure out how much water my mimosa trees need in summer. I have been trying to deep water them every 10 days or so. I have had this flat head bore worm in two of my trees and have treated it and think I have gotten them. I have one healthy tree that is seeing signs of something eating at bark on upper limbs. So maybe need more water not sure. So treated that tree for borer worms the other day. I just need to know how much or little to water in summer. Help please

I lived in wonderful WA for 30 years and have now moved to TX. I wanted another mimosa but the bare root one never took (first potted, then ground). The nursery replaced it for half price and again it did nothing in the ground. But never say die. I gave it one more chance by digging it up and potting it where I'd have better control over the water and sun. Actually put it in a slightly shaded area and now, after a year and a half my husband said it's growing. Didn't believe him and went out and sure enough it finally put out some tiny leaves. Problem is we're moving to Phoenix area in a month or so when new house closes. I plan to take a number of plants in pots (mostly roses) and the mimosa. One rose is rare and can't be replaced so I will try to find a professional to dig it up and pot it. We'll be trying to drive straight through with a small u-haul trailer with the plants. The nursery says it can't ship to AZ.
Does anyone have any feedback or suggestions?