What's Companion Planting?

Vegetable gardeners have long recognized the value of pairing plants in the garden. The objective might be to ward off pests, to optimize soil use or space. The practice is called companion planting, or sometimes combination planting.

Companion Planting in the Flower Garden

Traditionally, it was the old "put garlic among the rose bushes to ward off aphids," or "tomatoes and marigolds love each other" thinking. But there's a new focus (we're so great at redefining when we need to!) that is also interesting. This new focus brings companion planting into the floral garden and describes companion plants as ones that bloom together and look good together, are compatible in size and appeal. The new emphasis is on the placement of flowering and foliage plants in clusters that grow and bloom together to provide a continuous display through the season. An example garden might include a number of perennials, shrubs, bulbs and annuals, playing the colours, shapes, sizes and textures off one another to create a pleasing canvas of flowers.

Designing with companion planting

The bed of lavish perennials (below) begins in May with the lilac tree, its grey, lichen-covered branches and mauve blooms floating over the growing peonies. Artemesia has naturalized throughout the peony bed. Its silver grey foliage and tall habit are wonderful against the deep green foliage of the peonies before they bloom. During the bloom period the grey plays against the pinks of double and single flowers. Later, in mid-July, lilies, previously unnoticed at the edge of the peony foliage, jolt into bloom. They are mango coloured and look spectacular against the surrounding foliage in green and spikes of grey. Fortunately, these flower stems grow quite high and are profuse bloomers, lasting several weeks. At this time, it helps to trim back any annuals in the area to focus all attention on the lilies. The end of the lilies brings the garden bed to a mixed foliage finish, with the annuals carrying the colour.

(Note that with such large, heavy flowers, every stem of the double peonies is staked. Using driftwood as stakes inspired the addition of the artemesia.)

Planning for matching bloom times

In a bed where annuals are used to begin building the canvas, the purple coneflowers anchor from the back row. Their hundreds of blooms appear in mid-July and are very long-lasting. The addition of some white coneflower proves to enhance the crush of purple flowers. Slightly shorter than the others, they serve to open up the banks of purple. Spear-shaped leaves and tall stems provide a backdrop for the step down to purple veronica and the white of Queen Anne's lace.

While the main show is the beautiful coneflower, the annuals at their feet draw the eye toward the masses of bloom. Annual plantings can be different from year to year, although the flashy double begonia in yellow is a favourite. The lace and subtle colour of nigella also works well in this bed.

At the right hand side of the vignette the arbour carries the profuse Jackmanii clematis skyward. Its hundreds of deep purple blossoms start around the first week of July and last a month or more. This composition of purple and white is a tall display, requiring some consideration of flowers that will grow beside them.

A year-round canvas of plants

The third planting area (left) features bulbs and shrubs in an area sheltered from the harshest winter weather. The combination provides a year-round canvas, with euonymous, and nesting spruce noticeable throughout. The delicate branches of the spirea catch a lacy covering of snow in winter, highlighting their profile over the lower shrubs. Crocus, daffodils and the forsythia launch the spring display with a burst of sunny yellow and pass the charm to larger spring bulbs by early June. The peony and a beauty bush provide bloom cycles through the early weeks of summer.

Later in summer, with the final bloom on the peony and the beauty bush passing its peak, all attention is grabbed by the abundant white feverfew and pink spirea. Miniature roses and the nesting spruce take front-row seats. Notice the rich dark foliage of the purple leaf sand cherry.

Note:A groundcover of violets and hyacinths will protect the soil from hot sun and maybe shelter a toad or two. They are also good foundation plantings.

Vegetable Companions

The vegetable patch means a more utilitarian approach to companion planting. However, it's not without its visual delights. There is a long tradition in native culture of companion planting corn, beans and squash. The three vegetables grow co-operatively, with the beans using the corn stalks as a trellis and the squash prizing the shelter provided by the corn stalk as it grows tall and full.

The trio is referred to as the Three Sisters and is frequently the subject of Iroquois native carvings. I won't try this combination myself because my night shift-the raccoons-would use the beans as a trapeze to raid the corn.

Saving Supper-Companion Planting in the Vegetable Patch

To say that gardeners endure pest patrol is being kind. Handpicking bugs off plants is a tiresome chore. But consider this: if you take the perspective that not everything planted in the garden needs to be harvested, new possibilities unfold. For instance, herbs might be the solution to some pest problems and you needn't feel beholden to them as a food crop. A packet of herb seeds costs around a dollar and they can have a full life guarding the veggies in your garden. In September be sure to murmur thanks to each one as you yank it out and tote it off for composting.

Nematodes, the torment of the tomato lover, are repelled by marigolds. My experience with this combination is that you have to leave an honest three feet between tomato plants for the marigolds to flourish and do their job. I have had success planting the tomatoes four in a square with marigolds ringing the outside. I use French vanilla marigolds. You'll find tomato worm deterred by a planting of borage. As for tomatoes, veggie friends, keep the corn distant and the carrots close.

Beans, along with cabbage and carrots, all enjoy the benefits of being near the rosemary. It will dispatch bean beetle, cabbage moth and carrot fly (one I'm in no danger of encountering!). If it's a boiled dinner you're planning, your cabbage and onion will do well together with camomile as a neighbour. Note, though, that onions are not friends of beans and peas-keep them apart.

I am able to cajole only a few carrots into growing to harvest size, though they seldom reach the kitchen, acting instead as the garden snack. The experts, however, indicate that carrots benefit from proximity to beans, onion and tomatoes. Chives and sage both help manage carrot fly.

Other veggies don't aspire to share a row with potatoes, but they team up well with some herbs. Consider planting horseradish if you want help controlling potato bugs. Your salad patch will be the target of the undisputed king of pests, the slug. Dedicated sports, they first appear around NHL playoff time to start chewing on flowers and young veggie plants. Share your beer with them and they will converge at pool parties, lining up to dive in the beer dish (where they drown).

Consider these hints another tool in your organic toolkit. As a cautionary tale, my early experimentation with companion planting resulted in half my garden sitting out a season so it could be solarized to rid it of mint. The mint had mobbed the tomato patch! It is helpful to tomatoes (and cabbage) but keep a vigil on its spread.