How-To Ideas

Wine Corks Used as Mulch

Corks as mulch

I don’t know much about wine. While friends wax on about “hints of raspberry”, I’m happy that I can detect “notes of grape.” But I do know that I don’t like throwing away the wine corks. It doesn’t seem right. They are hand-harvested every 10 years from the regenerated bark of cork oaks, whose acorns feed those tasty Spanish pigs. So a dozen years ago I started saving our corks in a bucket, figuring I’d find a way to upcycle them if I kept a bunch handy.

Using Wine Corks as Mulch

While repotting a large ficus tree, I thought to try corks as a mulch and dumped them around the trunk. It looked like a jumbled mess. A mess made by people who drank a lot.

Asking myself, “What would a good designer do if one were here?” an image flashed in my mind. I stood them upright. Because they’re compressible, I could squeeze them in until they were all snugged up with a satisfying tension, like a little army of cork soldiers that wouldn’t float out of formation. This created a pattern of solid circles and triangular gaps like a mosaic floor, with some corks showing off their grape-stained bottoms. Herbaceous houseplants could send shoots up through the same gaps that water and fertilizer flow down.

Cork mulch

Cork mulch / Frank Hyman

But that’s not all. Corks don’t absorb water, so they don’t decompose: the cork mulch in that pot is 12 years old and in fine shape. And mulching allows me to water the ficus and other potted plants—aspidistra, a coffee tree, dwarf citrus–just once a month rather than weekly, leaving more time for cocktails. I watch for a change in the leaves such as curling or drooping to decide when to water. Alternatively, poke a chopstick between corks—like a toothpick in a baking cake–to check for dampness.

So try this first on a small pot. Then reward yourself with a tall pour of a favorite wine, put your feet up and think about which other houseplants need corking.

Get Supplies

·  One houseplant with potting soil no more than 2” from the top of the pot (the height of a cork).

·  A shim, such as a paver brick or scrap of 2×4.

·  Save your corks and ask the staff at a restaurant to save theirs for you in a bucket you provide.

·  For a 6-inch diameter pot, you’ll need about 35 corks; a 12-inch pot about 130 corks; a 16-inch square pot about 240 corks.

Make It

1) Tilt the pot back with a shim under the front.

2) Start placing the corks upright at the back of the pot. The tilt helps them stay upright.

3) Line up corks in the pot from back to front.

4) Squeeze in the last 5-10 corks in random spots so they are all snug.

5) Remove the shim and make any adjustments that your aesthetic sense calls for: setting corks at the same height, turning the stained bottoms down, etc. I like the random height/color look.

6) Water slowly. Too fast and water will splash around or float media over the top of the corks. If some corks float, add more to make a tighter fit.

7) Apply liquid fertilizer the same way you water the pot. You can also apply dry organic fertilizer by sprinkling it over the corks when they’re dry and sweeping it into the gaps with a whiskbroom.

Featured image by Frank Hyman.

Frank Hyman has a B.S. in horticulture and design from NCSU. He also wrote Henotpia: Create Hassle-free Habitat for Happy Chickens; 21 Innovative Projects.

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