Creating Indoor Topiaries
By Dr. Leonard Perry, Extension Professor
University of Vermont
If growing ordinary houseplants has become ho-hum, then it's time to try something a bit more challenging, such as topiary. You've probably been to places like Disney World or Green Animals in Newport, R.I. where there are life-sized plant sculptures of cartoon characters and animals. Well, you can create the same effect, only on a smaller scale, indoors at home.
Topiary, by definition, is the art of growing plants and training them over a frame to create a three-dimensional object. The word is also used to describe the finished product. The nice thing about topiaries, if you like to garden, is that they are a work in progress, requiring on-going maintenance to achieve desired results.
If you are new to this type of gardening, you might want to start with a simple, open-frame style topiary. Frames are available at some garden centers, or you can shape your own out of a coat hanger, chicken wire, or similar material. Circle and heart-shapes are among the most popular shapes for these topiaries although why not be creative? How about a star or triangle shape?
You will need a clay or stoneware pot with a drainage hole (pot size would depend on size of desired topiary), potting soil, sterile sand, twist-ties or cotton twine, and creeping vine-type plants with tendrils. English ivy is a good plant to use for your first topiary, as it's easy to grow and train. It is available in many varieties with different colored leaves..
To create a simple topiary, fill the bottom half of the pot with a mixture of half sand, half potting soil. (The sand adds stability.) Stand the wire form upright inside the pot. Add potting soil all around it, making sure the form will stay in place. Gently remove strands of ivy from the plant, being careful to include the roots. Place in the pot, covering the roots with an inch or two of soil.
Wind each strand of ivy separately around the topiary form, using twist-ties or soft cotton twine to loosely secure the ivy to the wire. Water thoroughly.
As the plants grow, continue to train the ivy to encircle the form, clipping and trimming as needed. Once the two ends meet, pinch the tips to encourage side shoots that can be trained to fill in empty spots and give your topiary a full, lush appearance. Fertilize every two to three weeks with an all-purpose houseplant fertilizer. Mist with water periodically.
Aside from English ivy, creeping fig is the most common plant used. Plants like grape ivy or philodendrons tend to have larger leaves, so are more suited for large frames. Choose small starter plants with long tendrils that you can plant close to the base of the frame.
Once you've mastered simple topiaries, why not try your hand at a stuffed frame topiary. In addition to the items needed for a simple topiary, you will need sphagnum moss, nylon fishing line, florist or hair pins, and a three-dimensional wire form. Animals are probably the most popular choice although a lot of people make holiday-themed topiaries such as Christmas trees, wreaths, and candy canes.
Start stuffing the frame with handfuls of dampened moss, packing it fairly tightly until the frame is filled. Use the fishing line to wrap and secure the moss inside the frame. The moss should be just poking through. You will want to use small-leafed plants such as creeping fig or many of the true ivies (Hedera helix).
Gently remove the plants from their pots, and rinse the soil off the roots. In the lower half of the frame, use your fingers to create "planting holes" in the moss. Insert the roots, then cover with more dampened moss. Use pins to hold the moss and the plants in place. As your plants grow, continue to pin and trim as needed. Many trailing types of plants will self-root as they grow.
Sphagnum topiaries will require frequent watering--soak in a sink full of water until saturated or put under the shower for 10 minutes--and regular pruning to encourage plants to develop shoots. Fertilize with a water soluble houseplant fertilizer on the same schedule as you would any houseplant.
Light requirements will depend on the plants used, but in general, topiaries prefer strong light but not direct sunlight, which can cause foliage to fade. During the winter months, you may need to supplement natural light with artificial lighting. Turn one-quarter turn every week to encourage symmetrical growth.
Finally, be aware that the same insect pests that bother houseplants may attack your topiary. So be on the lookout for pest and disease problems.