Front Yard area Grasses and Backyard Cherry Tree

Question: 1.) May I cut down our taller Grases (attached) in the backgroud to 6 inches prior to winter and expect them to return with nice growth next season?

2.) Regarding attached pics of our 25 year-old Cherry Tree in our memorial garden, our cherry tree (25 years old) is leaking what appears to be a molasses-like substance. Are you able to provide a perspective on our cherry tree, as to its health?

Thank you for your time and expertise.

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 September 10, 2024, 5:24 PM EDT
response: Ornamental grasses are usually left untouched until late winter, when old growth is cut back to make room for fresh foliage emerging later in spring. While you can probably remove the growth earlier than that (once it dies after a few frosts/freezes later in autumn), it will take away some of their decorative appeal, since foliage and seed heads often persist into winter unless flattened by heavy snows. That said, trimming off the seed heads for weedy non-native grasses would be ecologically beneficial (if the plants can't be replaced outright), though of course this also detracts from a key feature of using them. The grass pictured appears to be a type of Fountain Grass (Pennisetum), which are not native here, but not all varieties necessarily spread from seed. When a yearly cut-back is performed on ornamental grasses, about a six-inch height of "stubble" left is probably just fine, since it's best not to cut them back flush to the ground in case that damages growth points for next year. Warm-season grasses like Pennisetum won't really get going until later in spring as soil temperatures warm, so don't be alarmed if not much growth appears by March/April, but they catch up and fill in fairly quickly after that.  Ornamental/flowering cherry trees are vulnerable to a few pest and disease issues, and also can be stressed by certain environmental conditions like compacted soil and overly-wet roots (or poor drainage). Gummosis, the term for oozing sap, can be caused by several factors, including wood-boring insect presence, infection by fungi or bacteria, injury, or even just general stress from drought, over-watering, or other issues. There is no direct treatment or cure for gummosis. Borers tend to target trees that are wounded (such as by cuts to the lower trunk from mowers - not the case here it seems) or stressed, and fungal or bacterial cankers also take advantage of injured or stressed trees in most cases. No insecticide or fungicide will provide any benefit once symptoms of gummosis appear.  A certified arborist might be able to narrow-down a diagnosis by examining the tree in person, though they cannot treat or cure every condition. Ornamental cherries tend to have short lives compared to some other tree species, so after 2-3 decades, it's not uncommon for them to unfortunately decline. There does appear to be wound wood closing-over an old injury (maybe a crack in the trunk...it's hard to tell), so it's possible this damage is not severe or fatal, but we defer to the assessment of an arborist, who will be able to see more detail. Some arborists have more diagnostic experience than others, so you could inquire before hiring someone about their familiarity with ornamental cherry issues.  We realize that, as a memorial tree, you of course want to preserve it as long as possible, but unfortunately little can be done once decline sets in, though some actions might be proactively minimize stress going forward to prolong tree life. Examples include periodic irrigation during drought, reducing or eliminating any cultivation of the soil (digging/tilling) in the tree's root zone (especially close to the trunk), keeping the soil mulched (or covered with a living groundcover that doesn't need yearly replanting), and having any storm breakage pruned promptly and professionally so wood decay is less likely to set in while the wound closes-over.  Miri

responder: The Question Asker Replied September 10, 2024, 10:17 PM EDT
response: Thank you, Miri, for your thoughtful and comprehensive answers to my two questions.   I much appreciate your time and effort. Stpehen

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 September 11, 2024, 9:28 AM EDT
response: You're welcome!