By Kelly Wood
Among the many things I love about the return of Spring is the birds. I love the new growth, the bright green, the fresh buds of so many colors of flowers, but I love to see the songbirds return. Many birds are residents year round, and haven’t been completely absent because our feeders are kept full all winter.
Although I covet the electric birdbath heaters in the catalogues, the reality is that my more fragile bird baths come inside over the winter, while the others just freeze. Even on those days that are above freezing, I don’t see many birds bathing in the frosty air. It’s a fun ritual to bring back out the containers when freezing temperatures are gone for good.
Why not spruce up your bird facilities this year, and give them a lovely new bathing pool? It’s easy to do, and the results are striking.
Sand casting is surprisingly simple. I remember presenting my mother with the shapeless sand candle that I made at summer camp; it was so neat to carve a hollow in the sand that then was represented in 3-D when we pulled out the cooled wax.
These bird baths are exactly the opposite: instead of hollowing out the sand, you build it up into a pile and form the concrete over the top. The resulting shape is that of a bowl that holds the water.
- 1 bag of concrete mix (look for varieties that have “reinforcing” fibers mixed in)
- large leaves (see sidebar)
- Latex gloves
- Latex wall paint and brushes
- Spar Varnish
- Optional: drywall reinforcing mesh
- Optional: metal post base with flared bracket or wide flange
Identify interesting leaves around your yard or neighborhood. The bigger the better. Look especially for dramatic shapes and vein patterns.
Tropical plants perform well in this way. We used sunflower leaves, a hosta, rhubarb and a tropical “dinosaur-leafed plant” that I could never identify. I also made a few smaller casts from some nice nasturtium leaves, but their veining is fairly subtle. Note: Don’t pick the leaves yet!
Make a dome-shaped pile of firmly-packed moist sand slightly larger than the leaves you will be using. Make one pile per large leaf. This is best to do on a table at working height, since you will be leaning over it quite a bit. We put our sand into plastic bags for ease of clean up: I dumped the bags of used sand into my soil mix. Shaping the bags into the high cone or hill shape you want was a little more difficult than just loose sand, but it also helped keep the sand moist. If you use a plastic bag, be sure that it is smooth on top, or the wrinkles may show through on the finish.
Mix the concrete mix in a wheelbarrow to a soft, clay-like consistency. You don’t want it to be too wet or it will drip and ooze down the sides of your sand pile. Not too dry either: follow the instructions on the bag and use your hands to determine final readiness— modeling clay consistency works well. As added precaution, we wore gloves when touching the concrete, for the mess and also to avoid the chapping and drying that the lime in cement can cause.
If you want to, or have any experience with tinting, now would be the time to add color to your concrete. You could do green, as a basic overall leaf color, or perhaps even a brown. We stuck to the regular grey of the concrete, but it would be fun to see how the paint changes when the concrete itself is tinted. When you add color to the concrete mix itself, it will not wash out when cured, even if it is not sealed.
Now pick your leaves, and place them carefully face down on the sand piles. The larger veins are on the back, and give a more dramatic profile when the birdbaths are done. Make sure there are no folds or creases in the leaf surface as you press them out to flatten them and remove air pockets.
Start packing the concrete on top of the leaf in sections, starting with a moderately thin layer. You can always build it up thicker later, but make sure it is packed firmly against the leaf as you work your way around it, covering the entire thing. If there is any looseness in the packing, it could show up as an air bubble afterward. Pay special attention to the edges, as they are ugly if done sloppily (like mine were).
If you are doing an enormous leaf, it doesn’t hurt to reinforce it. You can get rolls of drywall reinforcing mesh at the hardware store, or you could try ¼” hardware cloth, but the rigidity may be problematic. We used the drywall mesh, and it was easy to work with. Be sure to cut the strips smaller than the leaf, or you could have little corners and threads sticking out hither and yon.
If you are going to stamp the flange shape of your stand into the back of your leaf, now is the time to do it. Otherwise, let the concrete dry and cure slowly, out of direct sun. Lay moist burlap or towels over it gently; newspaper dries too fast. If you cannot shade it, be sure to mist it often throughout the day so that the inside and outside dry at an even pace. Leave it for at least 24 hours; better to let it go for 48.
This is one of the fun parts: when you are certain that the concrete is completely dry, pick it up off the sand pile or bag and turn it over carefully. You will see the leaf stuck to concrete. You can try to peel it off while it is still moist, or you can set it in the sun to begin to dry. Sometimes it’s hard to wait, but the leaf material between the veins comes off more easily—peeling up by itself—as it sun-dries.
The veins are easy to pull up and out of the concrete channels. For any that are difficult, you can use a small screwdriver, toothpick, or bamboo skewer to pry them up. Be careful not to chip off any concrete. An old, dry toothbrush is useful for getting off the extra leaf bits. Pause here to admire the result… Concrete experts say to wait at least 30 days for it to be completely cured. You can set it aside for a week or more to start thinking about colors.
Paint it! We found that regular latex wall paint worked fine for the painting; it helps to have an unsuccessful leaf or piece of finished concrete to test out the paint first. Water the paint down to an impossibly thin consistency—we wanted more of a “wash” result than an actual painted surface.
The first color you paint will be the least visible, since most of it will get absorbed by the porous concrete. But it will also have the biggest impact on the later colors, as it will seal up many of the pores in the birdbath and will affect the absorption of the others.
Let each color layer dry thoroughly before doing the next one. A blow dryer helps to test the results in a hurry, but shouldn’t be relied on for complete drying of the paint layer. We did a very watery gold wash as the last or second to last color wash for some subtle luminescence. Let the finished product dry for at least 24 hours.
Coat all the leaf surfaces with Spar Varnish. This is a heavy duty varnish that has nautical applications. It will seal the paint into the birdbath and won’t impart anything to the water that would be bad for the birds. When dry, it is waterproof and UV resistant, and will supposedly seal the birdbath quite effectively so that it can be left outside year round.
I am not willing to take the chance over the winter, but it’s good to know in case you forget and a freeze sneaks in. There are two choices of finish: glossy and matte. I chose the matte finish, but it dried quite glossy because I applied it thickly. I went back and did a second coat since I wasn’t certain that all the veins and small pores were sealed. I ended up liking the gloss after all.
Glue your post base in, if you’d like, using a good waterproof epoxy. It shouldn’t get wet from the contained water, but environmental moisture from rain, mist and fog could serve to loosen a water-soluble glue. I attached my nasturtium leaves onto their little stands for a fountain with Gorilla Glue; I just rested the larger one on the post for the time being until I am certain where to place it. You can even rest larger leaves directly on the ground, in the midst of greenery as a surprise spot of color tucked into the groundcover.
Now watch as the local wildlife finds your little oasis. The veins and irregularities in the leaf pattern make good footings for bathing birds; squirrels and chipmunks will drink there as well. By providing water for them, you will bring more pollinators and bug-eaters into your garden and onto the farm. Without bugs, we wouldn’t get any fruit at all, and many pest insect populations would explode into unmanageable numbers if it weren’t for the birds that feed on them. Enjoy your beautiful artwork and give the birds and beasts a gift this summer—everyone will benefit.
Go to Birdbath Leaves to see photos of leaves that are ideal for your sand-cast bird bath.
About the Author: Kelly Wood steals large leaves from her parents’ pampered tropical plants in Portland, Oregon.
This article first appeared in the September/October 2009 Hobby Farm Home.