Pressing Botanical Specimens

Capturing the Garden

By: Denise Kelly
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http://www.variegatastudio.com

Denise Kelly has worked as a horticulturist in Northern California since 1978, with experience in wholesale and retail nurseries, landscape…

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The practice of horticulture is often described as a combination of art and science. And the practice of pressing botanical specimens demonstrates this nicely, I think. Every plant species has its own essence, so to speak, and capturing that unique morphological integrity can be very satisfying. To do this, carefully select plants to illustrate as many characteristics as possible; for example, the fine roots of a bunchgrass or the rather stout culms of sedge add a lot to a composition. If possible, it’s nice to collect an extra flower or two to press separately, especially if stems or other plant parts are large and will dry more slowly than the flower.

Dried specimen of Fraxinus latifolia, Oregon ash, with mature and immature leaves, twigs, and fruit, a winged samara.  Photo: Denise Kelly

Dried specimen of Fraxinus latifolia, Oregon ash, with mature and immature leaves, twigs, and fruit, a winged samara. Photo: Denise Kelly

When creating a composition, I lay the plant out on 11- by 15-inch heavy weight Strathmore watercolor paper, in a way that, to me, presents a classical representation of the species. Coaxing a leaf or twig just so can be done with forceps, pins, or painter’s tape: I tend to use anything at hand. Securing the piece in place with gummed linen tape can either be done at this stage or saved for final presentation on a clean sheet of mounting paper. This very much depends on how large and woody or moist the sample is. Very large specimens are best dried separately and then mounted once completely dry.

Top the botanical specimen with a clean sheet of blank newsprint or drawing paper and sandwich between several sheets of newspaper and two pieces of rigid cardboard. This holds everything in place and allows for air circulation and faster drying, which reduces the possibility of mildew and results in better color retention. At this point, a heavy weight is needed, (bricks, heavy books, a concrete stepping stone) or a plant press that can be cinched tight. A fan speeds the drying process, as does low humidity and warm temperatures (up to 95 degrees or so).

The first rule when collecting wild plants is to gain permission. Collect only a specimen or two, just enough, leaving plenty of plants to grow and thrive. Of course, collecting in your own garden is a fine way to practice the art as well. Even weeds can be beautifully pressed, elegantly shown below with a cousin of our ubiquitous lawn pest, the common dandelion.

Type specimen of Taraxacum reichlingii v. Soest (LUX 26313). National Museum of Natural History, Luxembourg.  Photo: National Museum of Natural History, Luxembourg.

Type specimen of Taraxacum reichlingii v. Soest (LUX 26313). National Museum of Natural History, Luxembourg. Photo: National Museum of Natural History, Luxembourg.

Once the specimen is dried and mounted, I like to leave room for an herbarium specimen type of label that includes the plant’s scientific name (genus, species, and infraspecies information), the collection date and location, and the collector’s name. (True botanical voucher specimens require much more detailed information.) The finished piece can be matted and framed for display or stored in a cool dry place; remember that the specimens themselves will be brittle and require careful handling.