Weeping mulberry: sparse patches of leaves towards top

Question: We’ve noticed over the past few weeks that there are patches of our weeping mulberry tree, at the crown and on several of the “shoulders”, where the leaves are sparse. This isn’t something we’ve noticed in prior years. For reference the tree is about 15-20 feet tall. It looks like there’s some new growth coming along in these areas. We are wondering if you have any ideas as to what could have caused the original problem, and if there are specific preventative and/or protective measures we should take, whether now or in the future?  (For instance, in looking around online, I’ve seen that silkworms are fond of mulberry leaves. Would/could silkworm feeding result in something looking like what we have going on?) The attached pictures show the tree from a couple different angles to give a holistic sense of the issue, and one closer-up picture of the crown. I would be happy to provide additional pictures and/or info if that could help. Thanks so much for your assistance with this!

responder: Julie Crick  Replied June 26, 2023, 9:45 AM EDT
response: Hi Chris, I see no evidence of injury, stress, or insect that would have caused this. Rather, this might be the growth pattern for the mature shrub.  In most cases, weeping trees are actually upside down trees, where a normally upward growing tree is grafted to root stock upside down to create the weeping effect. in other words, this tree would normally be growing with branches sweeping upward toward the sun. I suspect that in this case, the mature "upside down" portion is slow to produce branches on what would normally be the underside of the branches, where sunlight is generally scarce. The new growth suggests the tree is adjusting, and taking advantage of the area with increased sunlight by sending out new shoots.  The tree has good color and the leaves look extremely healthy. I suspect the new growth will fill in the bare spots over the next few months. If this is not the case, or if you notice signs of obvious struggle, please do not hesitate to reach out again.  Thank you, -Julie

responder: The Question Asker Replied June 27, 2023, 9:48 AM EDT
response: Hi Julie,Thank you so much for your response! I have an update for you: this morning, my wife came down to find a groundhog (!) in the tree, perched up on one of the shoulders, happily munching away on some leaves. This makes us think it’s the culprit. We know we have a groundhog in the vicinity, a pesky one that, but we’ve never seen it in this tree before… or in any of our trees for that matter. Haha, unbelievable, at least to us :-)Is there anything you’d recommend we do to dissuade this behavior? More generally: Have you heard of groundhogs doing this before??I appreciate hearing everything you said in your prior response as that helps bring us peace of mind about the health of the tree and—hopefully?—its ability to withstand some groundhog snacking.Thanks again for your help and guidance on this!chris On Jun 26, 2023, at 9:45 AM, Ask Extension <<personal data hidden>> wrote:﻿

responder: Julie Crick  Replied June 27, 2023, 11:30 AM EDT
response: WOW! I am sincerely surprised by the groundhog behavior. Would have never guessed them as a culprit! Some people wrap the trunk of the tree in metal flashing to keep critters from climbing the bark. Perhaps thick, clear bendable plastic would also work, and be less noticeable?  Thank you so much for the follow-up - and groundhog education! All the best, -Julie