October 29th, 2010
Recycled Glass Mulch
Mountain of glass bottles waiting to be crushed and ground into processed glass aggregate (the sandy looking stuff in front.)
This is one in a series of followup posts. We bloggers often write hopefully about new garden projects; I always want to know, “So how did it turn out?”
Dateline: May 4, 2008
Last Friday Vertie invited me along on her first trip to pick up recycled glass that the City of Austin has made available free to customers who want to use it as decorative mulch, for lining French drains, or to create a drainage layer under a raised bed.
I had seen pelleted glass mulch at the Springs Preserve and on the Travis County Master Gardeners tour and was interested in trying it–especially for free. The City of Austin doesn’t separate the glass by color so what you get is a mosaic of brown, green, and clear glass with the occasional blue shard and a lot of sand mixed in.
When we first saw it, we were both a bit surprised and disappointed. It seemed to be more sand than glass. We were told that over time the larger pieces rise to the top and the sand to the bottom. The photo below is how it looks two months later.
Although the glass has been tumbled in sand, there are still sharp edges. I hesitate to use it anywhere I’d have to weed and dig later (especially since I don’t wear gloves). I think in the future I will use it primarily in places I need to create good drainage.
The decorative glass mulch smells like a stale garbage can. A good rain should wash the scent and sand away.
How long do you think this will stay weed and leaf-free? At least when the revelers walking up from concerts at Auditorium Shores throw their beer bottles in my yard, it will blend in with the landscaping.
2008-07-05. The morning after Fourth of July celebrations at Auditorium Shores.
Followup: October 29, 2010
2008-05-02. I decided to put this batch along the front walk where I tore out the Spanish bayonets last January. I weeded the area and then put down weed blocker cloth before pouring about 3 inches of glass mulch on top. The yard drops sharply at one end and I rearranged the chunks of concrete I recycled when we remodelled our kitchen on the slope.
2009-05-03. A year later. The sand has settled and the large glass pieces risen to the top. I’m happily surprised that it does not collect leaves as much as rock mulch does. Generally it stays much cleaner looking.
2009-12-22. The agave is one of the most beautifully shaped ones in my yard. In the background, some recently-planted opuntia is already getting out of hand and flopping. Bluebonnet seedlings are salad plate sized.
2010-03-21. We had so much rain this fall and winter that the bluebonnets were spectacular. However, the agave was heavily damaged by the massive freeze Austin had in January 2010. It looks terrible and I’m so disappointed.
2010-10-03. The agave has recovered from the freeze damage ten months ago far better than I expected. The opuntia has grown and I’m now struggling to weed around the plants, put weed barrier down, put glass mulch around them. I know it’s much easier to put the weed barrier down first (really!); I just didn’t think the opuntia would be a permanent planting.
To sum up my experience, I like recycled glass mulch a lot. I’m no longer afraid of cutting myself on it. I use it to top off a lot of my potted plants. It has worn well and looks good even after a couple of years–which I can’t say for any other mulch, not even granite sand or decorative rock mulch.
How to Get Glass Mulch in Austin
Note: The location has changed since my original post.
“Color-mixed processed glass aggregate. Generated from the sorting of commingled materials picked up from the City of Austin’s curbside recycling program. Contaminants: Approx. 5%; includes paper and caps.”
1. Check out the website.
The City of Austin has moved the glass mulch from the Burleson Road location to the FM 821 Resource Recovery Center (south of ABIA). The city will load the glass mulch into a pickup for $9.64 per ton (no cash or credit cards, checks only). You can load it yourself for free.
2. If you are self-loading, be prepared.
Vertie and I brought every bucket and plastic container we could load into her car, our own shovels, and gloves. We brought a couple of containers that were almost too large for us to lift out of her car together when they were filled. Wet sand and glass is heavy! Also, we both foolishly wore our gardening Crocs. Wear tough boots! There is lots of large pieces of sharp glass all over the loading area.
3. Check in on arrival.
You will be asked to sign a waiver before entering the landfill.
by M Sinclair Stevens