Moss and Lichen in stone walkways - Ask Extension
While these look quite pretty, they are getting much too hard to control in our yard, garden and stone/brick walkways. Clearly they are happier and m...
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Moss and Lichen in stone walkways #786554
Asked April 12, 2022, 10:23 AM EDT
While these look quite pretty, they are getting much too hard to control in our yard, garden and stone/brick walkways. Clearly they are happier and more robust each year. What can I do to make the lichen and moss not happy to grow?
Cuyahoga County Ohio
Expert Response
Carl,
Thanks for sending these photos along with your question.
I for one love lichens and mosses. Although they may be a nuisance in the wrong spot.
Your bricks and side areas appear to be in somewhat shady locations. Lichens can survive in sun and shade. The air quality is good but you may need better air flow. Mosses can be slippery underfoot.
Cultural Control Reduce conditions favorable for growth of these hitchhiking plants by opening up the plant canopy to allow better air circulation and light penetration. Pruning both shrubs and overstory trees may be necessary. Reduce plant numbers to open up the landscape. Algae, lichens, and moss often become established on slow-growing plants. Therefore, improve plant vigor by proper fertilization, watering, and cultural management. In moist, humid climates, these practices probably will not eliminate these epiphytic plants, but they will reduce their number and vigor.
Chemical Control is also an option but I don’t recommend anything specific here. Identify and then read the label for instructions.
A number of fungicides not only will control fungus diseases but also will kill algae, moss, and lichens. The copper-based fungicides, mancozeb and lime sulfur, are examples. In order to use the fungicides, you must find the plant that you want to spray listed on one of these labels. Since the dormant season is a good time to apply sprays for algae, moss, and lichen control, follow the label directions for disease control during the dormant season. You will note that during the dormant season, these fungicides are used in higher concentrations, making them more effective. They should not be used at these concentrations during the growing season because they can injure the leaves. When using these sprays during the dormant season, be careful not to get them on evergreen plants nearby because leaves may be injured. Also, lime sulfur should be used carefully around painted structures because it can stain.One dormant spray should give adequate control. However, although the sprays may have effectively killed these growths, they will remain attached and visible for some time. Weathering and plant growth eventually will slough them off. The density of the original problem, the local environment, and the vigor of the plant will determine whether treatments are best
This link can provide more information. https://ohioline.osu.edu/factsheet/plpath-gen-12
Thank you.
Thanks for sending these photos along with your question.
I for one love lichens and mosses. Although they may be a nuisance in the wrong spot.
Your bricks and side areas appear to be in somewhat shady locations. Lichens can survive in sun and shade. The air quality is good but you may need better air flow. Mosses can be slippery underfoot.
Cultural Control Reduce conditions favorable for growth of these hitchhiking plants by opening up the plant canopy to allow better air circulation and light penetration. Pruning both shrubs and overstory trees may be necessary. Reduce plant numbers to open up the landscape. Algae, lichens, and moss often become established on slow-growing plants. Therefore, improve plant vigor by proper fertilization, watering, and cultural management. In moist, humid climates, these practices probably will not eliminate these epiphytic plants, but they will reduce their number and vigor.
Chemical Control is also an option but I don’t recommend anything specific here. Identify and then read the label for instructions.
A number of fungicides not only will control fungus diseases but also will kill algae, moss, and lichens. The copper-based fungicides, mancozeb and lime sulfur, are examples. In order to use the fungicides, you must find the plant that you want to spray listed on one of these labels. Since the dormant season is a good time to apply sprays for algae, moss, and lichen control, follow the label directions for disease control during the dormant season. You will note that during the dormant season, these fungicides are used in higher concentrations, making them more effective. They should not be used at these concentrations during the growing season because they can injure the leaves. When using these sprays during the dormant season, be careful not to get them on evergreen plants nearby because leaves may be injured. Also, lime sulfur should be used carefully around painted structures because it can stain.One dormant spray should give adequate control. However, although the sprays may have effectively killed these growths, they will remain attached and visible for some time. Weathering and plant growth eventually will slough them off. The density of the original problem, the local environment, and the vigor of the plant will determine whether treatments are best
This link can provide more information. https://ohioline.osu.edu/factsheet/plpath-gen-12
Thank you.
