Growing lemons in Fargo, clinging leaves and a bumpy lawn
Q: I just cut up the first lemon from my Fargo lemon tree, as shown in the photo, which also shows the tree from which it came. I wanted to try a new challenge by growing a lemon and lime tree, and each has produced one fruit so far. — Terinne Berg, Fargo.
A: Thanks, Terinne, for honoring my request to share your story with others, when I saw your lemon photo posted on Facebook.
Terinne writes, “I bought the lemon plant in 2018, and it’s grown from 12 inches to its current 30 inches. I’ve kept it outside during summer and bring it indoors in fall.
“The branch coming off the tree to the left in the photo is the one that held the lemon. I also have a lime tree, started at the same time, that’s now 48 inches high. It’s growing much faster than the lemon and has a lime that’s ready for picking also.”
Thanks, Terinne, for showing that we don’t need to go south to enjoy tree-ripened citrus.
Q: We have a Honeycrisp apple tree that’s behaving strangely. It’s January and it still has not dropped its leaves, despite our early, harsh winter. No other trees in our neighborhood are acting like this, and it’s never happened before. Is there anything wrong with the tree and is there anything we should do? — Chuck Peterson, Fargo.
A: Based on the number of similar emails, although with different tree types, this phenomenon is more common than usual this year. Several weeks ago, we addressed this with a silver maple.
When dead, dry leaves cling to a tree instead of falling, it’s called marcescence. Normally, the short days and gradually declining temperatures of autumn signal an “abscission layer” of cells to form at the point of leaf attachment that eventually unglues the leaf, allowing it to fall free. Sometimes early cold weather, frosts or other interference interrupts the process or kills leaves quickly before the breakaway cell layer forms, causing leaves to cling to the tree instead of dropping.
If leaves don’t fall normally, when growth begins next spring the old leaves are usually physically pushed off by the newly expanding buds. Marcescence isn’t necessarily associated with winter injury, so hopefully your tree will be fine. In the meantime, no action is needed.
Q: I’ve always enjoyed a beautiful lush lawn. I have it professionally sprayed four times a year and keep it mowed at a medium height, but a couple of years ago it started getting bumpy, thin in parts and hard to walk on. Could it be earthworms? If so, what can I do to get rid of them and get my lawn back to its beautiful healthy state? — Jeanne Strom, Moorhead.
A: The problems are likely caused by earthworms, as you suspect. Earthworms are a large group that includes the nightcrawler, and their role in a lawn is mostly beneficial. They help reduce thatch buildup by decomposing organic matter, and their burrowing improves aeration while increasing water and nutrient movement through the soil.
On the downside, in large populations these worms make the lawn noticeably bumpy and very uncomfortable for walking. Their activity can also cause thin patches in some lawns. Kansas State University calls the bumps on top of the ground "middens," a mixture of plant residues and castings (worm excrement).
How can nightcrawlers and other earthworm activity be controlled? Irrigating less frequently and deeper during the growing season will keep earthworm populations deeper in the soil, creating fewer bumps and middens on the surface. On the other hand, frequent and shallow irrigations from sprinkler systems can encourage earthworms to stay near the surface.
Power raking in mid-May and early September diminishes the bumpiness and reduces the amount of food available for population explosions. There are no pesticides currently labeled for nightcrawler control.
If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at firstname.lastname@example.org or call 701-241-5707. Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.