Carpenter ants are a symptom, not a cause of decay. Your Redbud is suffering from old age (40 years would be old for a Redbud). Unlikely the Magnolia, if it was planted in 1973 too, is in age related decline.

get rid of it ... period ...

i had one here when i bought this house.. it was about 25 years old.. and it started basically doing this ... though not on this scale...

i got rid of it ...

what smiv said about the ants ...

ken

Thanks.... We are planning on getting rid of it - I was hoping it was just age related and not something contagious to my magnolia... that would be a true disaster!!

i just said such on your sweetgum post ...

diseases RARELY cross over between species .. they are USUALLY highly specific ...

i just dont see a link between a redbud.. a SGum ... and a magnolia...

the only common denominator was the prior owner ...

but.. if you blast a mag in part sun ... into full blinding sun ... due to tree removal ... you might get some leaf burn and stress ... and it might get ugly... until it leafs out next spring ... but that should not be fatal in any sense ...

might make a difference which type of mag .... and where you are ... i dont recall off hand ... as e.g. GA sun is a lot different than MN sun ...

ken

Well the good news is the Magnolia is casting shade on everything else... it is far bigger than everything else in the yard. It is a huge beautiful tree that would devastate me to lose. Losing either of the other two would have no impact on the amount of sun that the Magnolia gets - if anything, it would only improve my view of the Magnolia :)

Erika, I'm so glad that you have such a love for your magnolia; they are magnificent trees.

Now is the time for you to learn how to protect your tree from unintentional injury. No digging, trenching, adding or subtracting soil, no adding sidewalks that cut through or compact the root/soil system in a very wide swath around the trunk.

Magnolias hate root disturbance and any of the above activities can be harmful.

Should you ever need to have work done to your tree, insure that you hire a knowledgeable certified arborist who will treat it with care and respect.

Speaking of tree work.....when you have the redbud removed, you need to have a guarantee that the magnolia will be protected during the process.

If trucks need to be drive onto the root system, they should lay down large sheets of plywood on the grass to distribute the weight, preventing compaction. It's your job to stress how important that tree is to you.

Redbuds get pretty gnarly in their old age. Yours looks to have a decent canopy. I say take a bit to decide if you are better off without it before killing it. I can see it as a neat feature in my more rustic back yard or at a botanical garden but as out of place in a formal suburb.

rhizo_1 - we did clean out under the magnolia - the previous owner had planted english ivy under it as well as used that area to deposit old branches / logs from other trees. My kids and I pulled up most of the ivy, I had to use Crossbow on some that we couldn't quite get to the root system on and then pull it up as it began to die. Hopefully all of that work won't damage it? Our plan was to then cover that area with pinestraw.... is that ok for a magnolia or is mulch better? Here in Georgia we use tons of pinestraw... I moved from Texas and we were mulch users.

I concur with that it is just old and no worries for your Magnolia getting infected. Redbuds often decline around that age and get areas of included bark that decay inside and then split later. They're great trees, they just don't last as long as some others. As long as it looks okay and isn't a hazard with potential targets underneath, I would leave it. As far as your Magnolia goes, use premium hardwood mulch at about a 2" depth. We don't use pine straw in the northeast. Be careful using herbicide under trees as you may get some absorption by fine surface roots. just don't over-apply. I would pull, mulch, then then spray whatever comes back through. This will give you some buffer for the herbicide. If you ever want tips for lawn, tree, landscaping, or pest control topics be sure to check out our blog on our website.