Question of the Week: May 26, 2016
“Neil, why are my plants’ leaves turning brown around the edges?”
The quick answer is “Moisture stress.”
Understanding edge and tip burn of leaves isn’t always an easy affair.”
After I tell people “moisture stress,” I watch their reactions. Maybe I’m working too hard. There is a certain number of people who accept that answer and are ready to go on, satisfied that they now are fully trained gardeners.
But there’s more to it than that. Think about our own bodies. When we have circulation problems, they manifest first at the points farthest from our hearts: fingertips and toes, as well as our noses. However, medical diagnoses are on a different floor than horticulture.
With plants, it’s the points farthest away from the roots. The tips and edges of leaves are the first places to get dry and the last places to get water. If you’re seeing browned edges and margins, it’s because the plant can’t pump water up and out fast enough.
Even grasses and other narrow-bladed plants like this liriope have edge and tip burn. Not surprisingly, the causes are exactly the same.
But it doesn’t stop there. You have to determine why the water isn’t getting there. Here are your most likely reasons:
• Plants got too dry (80 percent of the time).
• Plants have damaged roots.
• Plants have damaged stem tissues (borers, line trimmers, gouging, etc.).
• Temperatures are too high for the species.
• Wind was too strong and dried the leaves out.
• Plants were not acclimated to sunlight, or were intolerant of it in general.
• Too much fertilizer was applied (excessive mineral salts).
• And so, on and on to the conclusion. Perhaps at least this will get you thinking.