Q: Are the berries in the photo chokecherries? We’d like to make jelly, but want to be sure. — Shelly H.
A: I’m glad you asked, because the berries aren’t chokecherries, but are instead the fruits of a small tree or large shrub called common buckthorn. Its botanical name is Rhamnus cathartica, and the fruits cause severe gastrointestinal upset in humans.
Buckthorn is one of the most common plants for which identification is asked, because they pop up in unexpected places along shelterbelts and in landscapes, and people often wonder if the berries are edible. Although the fruits are toxic to the human digestive system, birds enjoy them and deposit the seeds as they fly, distributing buckthorn widely.
Buckthorn is considered a nuisance species almost everywhere, and aggressive campaigns in many states struggle for its containment and control. Its fast-growing nature and easy spread enable it to outcompete native vegetation and tree plantings.
Buckthorn can be identified by the prominent veins in the leaves and the pointed buds, reminiscent of a buck’s horn, providing its name. An easy way to distinguish between buckthorn and chokecherry is by the way leaves are arranged on the twigs. In buckthorn, leaves are arranged opposite each other, or just slightly below, termed sub-opposite. Chokecherry leaves are arranged along the twigs in an alternating pattern, rather than opposite each other, giving an immediate distinguishing feature between the two.
Q: My lawn is so thin from this year’s drought. Should I try to overseed this fall? — Henry T.
A: Autumn is normally the most successful time of the year to seed or overseed a lawn. If seeding is done between late August and Sept. 15, the grass will germinate, grow and establish well before winter.
This year, of course, is very different than most. Whether or not we should seed this fall depends greatly on your ability to water. Successful seed germination depends on keeping the soil surface dark-moist continually. This often requires watering twice a day, sometimes more on windy days. Grass seed that sprouts can easily fry and die if neglected on warm, windy days.
Cool fall temperatures and Mother Nature’s autumn rains can help seeding be successful, but attention is still required. The subsoil moisture is severely depleted in many areas of the Upper Midwest, and recent rains have helped greatly, but haven’t been nearly enough to replenish the soil.
Whether or not to reseed this fall is difficult to predict. If timely rains and cool temperatures assist your watering routine, then all will be well. If the fall is hot and dry, it will be difficult to keep a seedbed moist.
Q: I delayed planting our plum tree because it was so hot and dry all summer. I’ve watered it in the pot and kept it in a protected spot, and it looks really good. Can I still plant it this fall? — Jake N.
A: Fall planting can be very successful for trees and shrubs. The cooler temperatures of autumn reduce the stress on newly planted material, and it’s easier to maintain proper moisture after planting. Trees planted in the fall begin making root growth, giving an advantage over delaying until spring. For best results, plant before the end of September, allowing more root growth time before soil freezes solid.
Subsoil moisture is almost nonexistent in many areas, so after digging the planting hole, fill it completely with water several times and allow the moisture to percolate down before planting the tree. Water well after planting to ensure good soil-to-root contact.
Fall-planted trees will establish well with once-a-week waterings of about 5 to 7 gallons for the average 6-foot tree. Daily watering can quickly drown a tree from lack of soil oxygen.
If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at firstname.lastname@example.org. Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.