When designing gardens, knowing about plant forms can help you create a design that looks good and that gives a particular overall feeling, such as formal, relaxed, or whimsical. In The Complete Planting Design Course, Hilary Thomas writes that “the form of a plant is its overall shape when in leaf.”
Some common forms of plants are
- Round: Some plants naturally from into round shapes. Others are ideal for pruning into round forms. Round forms are ideal for formal gardens and to use as accents within flower beds.
- Dome: Many plants naturally form a dome. Some flowers also provide a dome affect. Dome forms give a relaxed feeling, can soften edges of borders, and can provide a transition to other flower beds.
- Columnar: The branches of some plants ascend upwards can create a tall, slim form. The columnar form makes a nice focal point in a garden as it catches our attention. (Notice that when they are placed on either side of a front door, our eyes are drawn to that area of a house.)
- Conical: Many conifers have a conical form (like our Christmas trees). A conical form gives a formal feeling and also provides a nice accent within a flower bed. (It doesn’t attract as much attention as a columnar form, so you may want to choose a conical form depending on your goals.)
- Arching: The branches and leaves of some plants begin by ascending upwards and then fall over to form a fan as they mature. These plants need plenty of space around them to look their best.
- Spiky: A spiky form consists of branches and leaves that ascend upwards and are fuller at the top then the bottom (like an upside down triangle). They provide a more relaxed feeling. They also look nice as accents with trailing flowers growing all around them. (Notice that when they are placed on either side of a front door, they attract our attention but provide a more relaxed feeling than columnar forms do.)
- Trained: Some plants are ideal to use as topiary, or clipped hedges, into various shapes—squares, spirals, and even animals. Having several trained forms in a garden can provide a sense of order and a feeling of maintenance and care. And when clipped into eye-catching shapes, training forms can serve as garden artwork.
Learning about a plant’s form and habit when it reaches maturity is a key consideration when designing gardens.