Eastern Redbud Sapling with some leaves being eaten and others with dried out tips

Question: We planted a healthy eastern redbud sapling a few weeks ago in a Southwestern suburb of Baltimore on a western edge of our property near the sidewalk.  The tree arrived with paperwork indicating that it was free of pests.  Our property slopes slightly downward from the sidewalk toward our house where the tree is planted.  The tree is vertical and gently held in place with three stakes.  We dug the hole at the correct depth and width and mixed the local clay soil with topsoil and peat moss to fill it.  We tamped down the soil well and have watered the tree with a drip daily (except for rainy days).  About a week ago, we began to notice large missing areas on previously healthy leaves and drying tips (that appear black) on other previously healthy leaves.  

Prior to this tree being planted here, we removed a very old lilac bush that was dying back.  It was very large and old back in 1998 when we moved here.  We took good care of it, and it bloomed beautifully until about a year or so ago when parts of it began to die back (starting with multiple black spots on its leaves).  We would cut off the dead branches, but it eventually entirely died.  When we removed it, we also removed all of its remaining very woody roots.

Please help us save our little tree!  My guess is that more than one problem is occurring here.  The "holes" in the leaves clearly seem to indicate some sort of hungry pest, while I'm not sure about the black tips. I have more photos available beyond what I've uploaded here, if that would help.  (This site only allowed me to upload three photos.)

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied July 06, 2023, 2:20 PM EDT
response: Hi,  The pictures are somewhat blurry on our end and we are unable to zoom in on them to clearly see black tips, however the leaf chewing is probably nothing to be overly concerned about. There are many leaf chew insects that are present this time of year and most are native, so native insects on a native tree is good! Leaf cutter bees, many beetle species, various caterpillars etc. If you feel like the damage is too harmful to the young tree, you could go out with a flashlight at night and pick off any culprits you may find.  Watering every day is most likely too much for the tree. You can read our watering guide for trees and shrubs, but if you use a drip hose and run it about once a week (or twice if its been really hot and no rain) and let it thoroughly soak the entire area allowing the water to percolate through to the deep roots, that would be sufficient. If the soil can't dry out in between watering times, the plant can become susceptible to root rot disease. You can feel the soil down to about 3-4 inches and see if it is still wet, and if so give it a few more days to dry out a little more before watering again.   If you wanted to send in additional photos of the black spots on the leaves, that could help to see if its any common issues. You can try to send them in PDF file format and that may allow up to zoom in to clearly see.  Emily

responder: The Question Asker Replied July 06, 2023, 5:27 PM EDT
response: Thank you, Emily.   I may indeed go out at night with a flashlight, because SO many leaves are starting to get totally decimated!   (I did send my pictures in pdf file format… However, I didn’t send them in their actual size, because the file may then have been too big to send. Perhaps that was the problem.) I’ll try sending just one that is large, and I’ll note the # above that you put in the subject line.  Thanks again, Diana

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied July 07, 2023, 3:34 PM EDT
response: Hello Diana,  We received JPG-format images, so perhaps those sent via PDF did not transmit for some reason. In either case, we are starting to see leaf damage on a variety of plants from night-feeding beetles like Asiatic Garden Beetle and their kin (cousins of Japanese Beetles). Other insect leaf-chewers include katydids, crickets (there are some "tree crickets" that don't live on the ground like field crickets do), grasshoppers (less common in trees, though), earwigs, leafcutter bees (they carve-out semi-circles in the leaf edges for bundling-up their eggs and are fond of redbuds), caterpillars, sawflies, and plenty of beetle species. Fortunately, even though their chewing can create a bit of an eyesore, these are not serious pests and do not warrant intervention with an insecticide.  As long as the redbud's roots remain healthy and its trunk undamaged, the minor loss of some foliage to damage is inconsequential, especially the later we get in the growing season. If deer happen to visit the yard, protect the trunk from antler rubbing by bucks in the autumn with a cage around the trunk or some other protective barrier that doesn't smother the bark. Deer can eat redbud foliage too, but only while they can reach it.  Minor infections can also cause leaf puckering and brown dead spots (many of which are just collectively called "leaf spots") but these too are not serious and just a cosmetic nuisance. In years with wet or very dew-y weather the fungi or bacteria might spread more prolifically, but you can rake-up fallen leaves in autumn (of if they fall before then) to reduce the presence of spores in the vicinity. This is not a foolproof way to prevent infection in future years, but plant diseases tend to be very weather-dependent in their spread and severity, so an outbreak one year won't necessarily repeat itself to the same extent the next. Redbuds are not super disease-prone plants with regards to leaf spots; the more serious infections occur in roots that are stressed or damaged, or in branch wood that is similarly stressed or injured.  Lilacs can develop wood-boring insect (a moth caterpillar in this case) infestations as they age unless regularly pruned to discourage the moth's interest, and they are also vulnerable to several leaf infections, though different than those that might be present on a redbud. They also struggle over the long term in our summer heat, preferring cooler conditions, so many garden lilacs in our region decline after several years. In this case the lilac's struggles are unrelated to anything the redbud will experience unless the soil drainage in this location was poor, which both plants will not tolerate well.  You can keep an eye on it for now, monitoring it for watering needs before each soaking so it isn't watered too often, and feel free to send us more photos of symptoms if they worsen or change. Leaves can't heal from damage so any existing symptoms won't disappear, even if the cause of them is resolved, but you can look for indications younger growth is developing damage.  Miri

responder: The Question Asker Replied July 07, 2023, 4:30 PM EDT
response: Thank you for your detailed response.    Since so many of the leaves are being almost totally consumed, would it be ok if I sprayed the leaves with a homemade mixture of garlic, oil, and dishwashing liquid (following “recipes” online)?  I’d hate for this tiny tree to lose every single leaf when we’re not even half way through the summer yet.   And you’re right.  My mistake.  Those were jpg files not pdfs.  I now turned one of the photos with the dark dry tip on the leaf into a pdf and have attached it plus two new photos that are clearer.  Perhaps you can tell me what you think is causing that.     Thank you, Diana

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied July 07, 2023, 5:42 PM EDT
response: The damage pictured may look jarring but it's actually fairly minor and typical of many tree leaves by summertime. Trees can afford to lose some foliage (as they would in storms, deer browsing in the wild, or from a variety of other reasons) and as long as the roots are healthy, regrowth to compensate is possible in future growing seasons. We don't see any cause for immediate concern that would warrant any sort of pesticide use.  We do not recommend any home remedies as there are a number of risks (in addition to the fact that many just won't work well) to plant health and using such a mixture could easily do more harm than good. Penn State Extension has a thorough page discussing why home remedies in general are not a good idea as pesticide alternatives. (Granted, some of those scenarios they describe don't apply to every use of a home pest-treatment concoction, but they still make valid points. The take-home message is that plant damage is easier to do with these untested ingredients and arbitrary dosages, and impacts on the environment of those household ingredients used in this way could be detrimental.)  The dark blotch on the leaf tip is either abiotic (caused by environmental stressors and not pests or disease) or an unconcerning leaf spot disease or potentially anthracnose. (As an example, many mature sycamore trees in the area were hit with anthracnose outbreaks this spring and they have since shed affected leaves and recovered well with lots of new canopy growth.) Fungicides, even a labeled pesticide product, will not cure existing infection. At best, they help prevent new infections, but not all pathogens keep re-infecting their host plant all throughout the summer. Even those that do aren't always treatable with a fungicide, and such treatments tend to require multiple sprays that might expose beneficial insects to the pesticide (even though that pesticide doesn't target insects, it can still affect bees and other species). These are the reasons why we generally don't recommend fungicides for leaf spot issues; they either risk not working well, could be more trouble an expense then they are worth (since trees don't suffer long-term health setbacks), or are applied too late because once symptoms manifest little control can be achieved.  If any leaves are being totally consumed -- that is, missing entirely or quite torn-off and mostly-missing -- then we suspect deer are responsible as redbud is not unpalatable to them. In that case, a repellent spray might help discourage them (reapply as the label states, which is often after heavy rains) or a physical barrier like a cage/fencing that is removed as the trees mature enough to be out of reach. The only other pest that might defoliate redbud branches would be a communal-feeding caterpillar (Fall Webworm, for instance) but they are fairly unmistakable as they create prominent webbed-together leaf shelters that we don't see here. Sometimes a minor infection weakens leaf tissue (since it creates a dead zone of cells that dry out as the die), and then this brittle area is more prone to tearing during wind or storms, so the leaves get a tattered look as we get later into summer. This is fairly common but should be less prominent as trees mature and have a bigger ratio of intact-to-damaged foliage.  Miri