Care of plants in rock mulch. - Ask Extension
In 2014 our landscaper used river rock mulch in some of our Colorado Springs yard. There is heavy fabric under a thick layer of rocks and a water dr...
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Care of plants in rock mulch. #272989
Asked August 25, 2015, 7:15 PM EDT
In 2014 our landscaper used river rock mulch in some of our Colorado Springs yard. There is heavy fabric under a thick layer of rocks and a water drip system. Do the rocks need to be pushed back from the base of the plants and the fabric cut back to allow healthy growth? The plants in question are Blue Oat Grass, Elijah Blue Fescue, Siberian Iris and Silver Mound Sage. Thank you.
El Paso County Colorado
Expert Response
Thank you for your question.
Do you have the capability to send me a few pictures?
Rock over landscape fabric is a common mulching material often considered as low maintenance. It is the preferred material for non-plant areas. Rock mulch has the advantage over wood/bark chips that it does not blow, float, or require additional amounts every few years as it decomposes.
Rock mulch can become a heat sink, creating a significantly warmer afternoon, evening, and nighttime microclimate. Outdoor people space adjacent to rock mulch will be warmer and less comfortable for summertime afternoon and evening use. In planting beds, rock mulch increases temperatures and may increase water requirements.
Do you have the capability to send me a few pictures?
Rock over landscape fabric is a common mulching material often considered as low maintenance. It is the preferred material for non-plant areas. Rock mulch has the advantage over wood/bark chips that it does not blow, float, or require additional amounts every few years as it decomposes.
Rock mulch can become a heat sink, creating a significantly warmer afternoon, evening, and nighttime microclimate. Outdoor people space adjacent to rock mulch will be warmer and less comfortable for summertime afternoon and evening use. In planting beds, rock mulch increases temperatures and may increase water requirements.
Rock mulch may interfere with shrub rejuvenation.
Perhaps these pictures will help make clear my question. Since the 2012 Waldo Canyon fire, we have many fire/insurance regulations regarding landscaping. We are one of the families that lost our home and respect the purpose of the regulations, but it often means using rock mulch even with plants. Most of our plants are doing well, but you can see that especially the Blue Oat Grass is struggling. I am asking for guidance for ongoing plant care in the rock mulch.
Hello,
thank you for sending pictures .
I am sorry to hear that you lost your house in the Waldo Canyon Fire. Thank you for building again and staying in the area.
As Kerry pointed out in her previous email: heavy fabric and rock mulch covering your soil is not the ideal situation for optimal plant growth.
Since your drip system is under the fabric, frequent inspection of the soil moisture around your plants might be necessary. You could have a leak in your drip system or a dripper missing or clogged.
Blue Oats grass is a cool season grass. If the area of your landscaping is on the south side of your house the rock around the grass could create a heat sink and just be to hot for it to flourish.
Assure that the area around the root system of each plant will leave space for your plant to expand. If not you might have to widen the fabric some.
The most important thing is to check how wet or dry the soil is around your plants and adjust your watering accordingly.
I hope this helps. Let us know if you have any other questions.
thank you for sending pictures .
I am sorry to hear that you lost your house in the Waldo Canyon Fire. Thank you for building again and staying in the area.
As Kerry pointed out in her previous email: heavy fabric and rock mulch covering your soil is not the ideal situation for optimal plant growth.
Since your drip system is under the fabric, frequent inspection of the soil moisture around your plants might be necessary. You could have a leak in your drip system or a dripper missing or clogged.
Blue Oats grass is a cool season grass. If the area of your landscaping is on the south side of your house the rock around the grass could create a heat sink and just be to hot for it to flourish.
Assure that the area around the root system of each plant will leave space for your plant to expand. If not you might have to widen the fabric some.
The most important thing is to check how wet or dry the soil is around your plants and adjust your watering accordingly.
I hope this helps. Let us know if you have any other questions.
