Saturday, July 28, 2018

Rock-scaping in Florida: A good idea or not?

2008: A blue bee goes crazy in a prickly pear flower.

Rock-Scaping in Florida:
a cautionary tale

It all started simply enough in 2005 when someone gave me a few pads of prickly pear cactus (Opuntia humifusa), a Florida native.

I had no clear idea what I was going to do with them, but you know how it is. It seemed like a good idea at the time, so I rooted them in a couple of pots.

Meanwhile, my husband and I were totally redoing the front and side beds, because they were a weedy mess. The previous owners had covered the beds with lava rock and the weeds loved it. We removed the rock from the beds, put it in a pile, and then rinsed the soil away.

We'd just moved to Florida in June 2004 and after our 4 hurricane welcome that summer and into the fall, I'd planted my now famous 64 tulip bulbs that I purchased at a local store. When only one leaf sprouted the next spring, it made me mad that the stores were selling stuff that was guaranteed to fail. I began writing columns for Jacksonville's Times Union Newspaper as a community columnist. I called my columns, "The Adventures of a Transplanted Gardener," which led to a whole writing career, but that's another story.

We capped a sprinkler head at the intersection of the driveway and the front sidewalk and built up a mound to the cacti would have a nice dry habitat. Then I wrote a full column on the whole front and side bed projects called "Ooh la la! French drains." I'm embarrassed to say that we laid down weed barrier cloth and cypress mulch. We've learned so much since then.

2005: At one point, the lava rocks hosted a small scarlet snake for at least several weeks. 2008: 3 years later, the prickly pear had filled in nicely

So is rock-scaping sustainable in Florida?

In this case NO.

In more arid landscapes, rocks can be beautifully arranged almost like a mosaic and will need almost no upkeep. In Florida, with our 50" of rain, continual leaf drop. rampant weeds, and fire ants, the rocks fill up with soil. I've had to clear out this rock-scape every few years. It's a lot of work, and as far as my back is concerned, it is not sustainable from a maintenance perspective, but when it's cleaned up, I do like it and so do the pollinators.

As you can see, we've also added a yucca or Spanish bayonet (Yucca aloifolia) into the mix. The cacti have aged and their base pads have turned gray, so over the last year, I've cut back the old ones and started again by rooting new pads. I still have some work to do to restore the cacti on the sidewalk side of the bed.

A week ago: It was time to clean out the rocks, yet again. I'd pulled out almost all the lava rock with the all accumulated leaves and dirt. I left the weed barrier cloth in place here to keep the rocks separated from the soil.  Today: The rock-scape has been reconstructed, and looks presentable.

We removed the completely ineffective weed barrier cloth in front of our hedge. I mulched it with arborist woodchips and have transplanted some frogfruit ground cover (Phyla nodiflora) from the lawn. This way the weeds will have to complete with this beautiful, native ground cover. 
If you looked at the French drain article, you can see how much these shrubs have grown. These are the "dwarf" yaupon holly (Ilex vomitoria "nana"): a male clone that blooms, but never gets berries and while they may grow slower than the wild, native yaupon hollies, they are still too big to use as a foundation planting.

As gardeners, we are always learning and adjusting our ways to live in better harmony with our only planet. (Update: three years later, we took out all the cacti and all the gravel. The big volcano stones are still there around the yucca, but now it's all mulched with wood chips. It was just too much work to keep it looking good. 

Green Gardening Matters,
Ginny Stibolt


  1. Thank you Ginny for sharing this. I will add that rocks under the roof dripline allows the removal of gutters, thus equal distribution of rainfall in the yard. Also, rocks hold solar heat

  2. williammantz9@gmail.comJuly 3, 2023 at 4:52 PM

    Rocks under the roof drip line prevent erosion, but in the yard hold and reradiate heat