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During a recent Arbor Day event, North Carolina Governor Josh Stein announced that the 2025 NC Tree of the Year is the White Oak, Quercus alba. White Oak is a great choice for a number of reasons. Its native to NC, fairly easy to grow, free of any significant insect or disease pests, and likely to play a big role in the reforestation efforts in western NC following last year’s Hurricane Helene devastation. What about locally? White Oak is also happy in our Eastern North Carolina soils and climate, and makes a fantastic shade tree. At a mature height of about 80 feet tall and 50 to 60 feet wide, it is not a tree that is easy to fit in every backyard, but it is often used in parks and public spaces to provide shade for visitors. One of many species of oak found in NC, Quercus alba is notable for a few reasons. It has finger-like lobes that lack the sharp bristle at the tip of many other species. Leaf color is a pale green that is not quite as dark or glossy as other oak species. Compare their leaves to a red-oak type such as Quercus falcata or Quercus palustris, and you’ll probably come to the conclusion that White Oak has a softer, gentler appearance.
In the fall, these green leaves turn a burgundy red or coppery orange color, providing excellent fall color throughout several weeks in autumn. And then, something unusual happens, and this is the part of the column where you learn some fun new horticultural terms to impress your friends at parties. Instead of falling to the ground, a large portion of the leaves stay attached to the tree, turning brown and persisting throughout much of the winter. Why does this happen, you may wonder? Deciduous trees typically form a cluster of cells at the spot where a leaf’s petiole (a short stalk-like structure at the base of a leaf) attaches to a branch. Botanists refer to this as the abscission layer. As this area swells in autumn, it eventually reaches a literal breaking point where the petiole snaps off the branch and the leaf falls to the ground. Certain species of oak, beech, and ironwood often don’t fully develop this abscission layer, and thus dead leaves remain on the tree during the winter. Retention of dead leaves during the winter is referred to as marcescence. These marcescent leaves will gradually fall off one by one over the winter months due to rain, wind, snow, and other elements, and any that remain in the following spring are pushed off by the emerging new foliage.
Beyond this bit of botanical curiosity, oaks are an important food source for a number of wildlife species. We may not want to attract all of these to our home landscape, but deer, squirrels, and many other small mammals feed on acorns, and a number of songbirds, butterflies, and moths also feed on foliage and other plant parts. Acorns are even edible to humans, once the tannins are leached or boiled out. I will always recall fondly a long conversation I had early in my career with a local naturalist in Halifax County, who had determined after much experimentation that White Oak was the best species to make acorn coffee from. I decided to simply take his word for it, rather than experiment myself. Matthew Stevens is the County Extension Director and Horticulture Agent for North Carolina Cooperative Extension’s Pitt County Center. If you have questions about this article or gardening in general, please contact the Pitt County Extension Master Gardeners at [email protected] or 252-902-1705.
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Imagine you are walking barefoot, peacefully through the grass in your backyard. Your feet lightly tread on the soft green turf and the grass blades are tickling you softly between the toes. All of a sudden, you step on something sharp and hard, and your once-delicate stroll ends with you screaming out in pain. You’ve just stepped on a burweed. Or maybe you call them spurweed. Either way, you’ve stepped on a cool season annual broadleaf weed that produces a hard-coated spiny seed, and boy does it hurt. Now for the bad news. Once burweed has matured to the point of producing seeds, it’s very difficult to control. As a cool-season annual, burweed has been growing in your lawn since sometime last fall, but you haven’t noticed it until now. The good news is that the plants will die as the weather warms up, but those prickly seeds will stay in the lawn for a good while. Herbicides containing 2,4-D might kill the plants a little quicker, but they won’t get rid of the seeds. If the plants are contained in a relatively small area in the yard, you may be able to remove a good amount of the seeds by doing a thorough hard-raking of that area.
Above left: A burweed clump, about the size of the palm of a hand. It looks innocuous, but its effect is anything but. Photo: H. Rose, CC BY 2.0 Above right: Burs. The burs blend in well with the ground, causing untold misery to anyone walking barefoot and unaware of what lurks in the lawn. Photo: M. Lavin, CC-BY-SA 2.0 The best control against burweed is preventative – using pre-emergent controls that stop the weed before it comes up. Many of the same pre-emergent herbicides commonly used in the spring time to control summer annual weeds such as crabgrass can be used in the fall for weeds like burweed. Remember this in the fall to stop next year’s plants. 2,4-D can also be used during warm periods in late winter and early spring before the spines form. Lawns with centipede grass should avoid 2,4-D other than at very low doses, as it can cause harm to centipede, and instead use products containing certain formulas of the chemical carfentrazone, such as Quicksilver and Speedzone.
At the risk of being confusing, there is a similar weed that comes out during summer called sandspur. This weed also forms a hard, spiny seed that will make you shout naughty words if you step on it. he difference in terms of control is partly recognizing the time of year the weed is actively growing, but also knowing that sandbur is a grassy weed, whereas burweed is a broadleaf weed. That means the chemical options are different. For grassy weeds, post-emergent control is very difficult because nearly any product that will kill the weed will also harm or kill the turf it is growing in. Pre-emergent controls are generally the best option for grassy weeds like sandbur, and unfortunately, it’s now a bit too late for that this year. Heavy infestations of burweed or sandspurs in lawns are usually indications of poor grass stands and low-quality soils. While herbicides may help temporarily, you’ll need to take some other measures to strengthen the lawn for better long-term control. Visit www.turffiles.ncsu.edu to view a maintenance calendar specific to the type of grass you are growing, or visit the extension office and ask for a publication called Carolina Lawns. Either option will give you lots of helpful information about how to care for your lawn so that you are less likely to deal with problems like burweed and sandspurs. Matthew Stevens is the County Extension Director and Horticulture Agent for North Carolina Cooperative Extension’s Pitt County Center. If you have questions about this article or gardening in general, please contact the Pitt County Extension Master Gardeners at [email protected] or 252-902-1705. |
Matt Stevens
Pitt County Extension Director & Horticulture Agent Archives
June 2025
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