By Dr. Susan Hamilton
In my home landscape, you won’t find a dedicated vegetable garden, herb garden or cut flower garden. My entire landscape is a demonstration of interplanting different types of plants and the beauty and utility you can gain from such a gardening technique.
I have a blueberry bush planted next to an antique rose, which in the summer is also paired with fragrant basil surrounded by nonstop blooming low-growing petunias. This palette makes a colorful, showy statement in my garden, and I love picking the blueberries.
Where the street curb and my front yard intersect, I grow a selection of ornamental hot peppers that produces oodles of showy yellow, red and orange peppers all summer. They complement a nearby perennial clump of gold-flowering rudbeckia (also known as black-eyed susans), and together they make a striking contrast to the red tomato planted nearby. It’s not just aesthetics. Interplanting flowers, herbs, vegetables and fruits creates some benefits that enhance the overall success of my garden.
Attract Pollinators, Avoid Pests
Vegetables don’t always have the showiest flowers. To make sure the bees and butterflies find your veggies, interplant flowers with high nectar concentrations such as mint, sweet peas, cosmos, zinnias, larkspurs and marigolds. Flowers that are blue, yellow or white are the most attractive to pollinators.
Second, interplanting allows for fewer pest problems. A diverse garden creates a complex environment that helps attract beneficial insects and natural enemies to insect pests. Lady beetles are a fascinating example. They eat insect pests in both their immature and adult stages. Lesser known insects such as lacewings, syrphid flies and parasitic wasps eat other insects when they are immature, and then benefit the garden by acting as pollinators as adults. Parsley, dill, coriander (cilantro) and flowers from the aster family are especially good for attracting beneficial insects.
Be careful about planting vegetables that belong to the same family together, as they make for an easy target for plant-specific pests. For example, don’t pair up tomatoes, potatoes, peppers and eggplant. The Colorado potato beetle finds all of these delicious. Plant tomatoes and corn away from one another because the tomato fruitworm is also known as a corn earworm. And squash, cucumbers, pumpkins and melons share the same enemy: the pickleworm. Also, fewer diseases occur when the garden contains a mixture of plants.
The same goes for weeds, as mixed plantings capture a greater share of available resources than sole crops, leaving fewer resources for weeds. Interplanting typically provides greater soil coverage while shading and crowding out unwanted weeds.
Interplanting Saves Space
The method of companion gardening takes advantage of every inch of garden real estate. A handy method for anyone, interplanting is especially popular with those who have limited space.
Instead of planting in rows with wide open spaces, select plants that can grow in between and around each other without competing or crowding. Make sure the plants thrive in the same conditions with similar light, water and soil preferences.
Interplanted specimens should have different types of root systems, such as shallow rooted, medium rooted or deep rooted, so they won’t compete directly with each other. Corn, broccoli, spinach, cabbage, lettuce and the majority of flowering annuals are all shallow-rooted plants. Cucumbers, turnips, beans, summer squash, carrots, peas and a good portion of flowering perennials have medium-length roots, while tomatoes, asparagus, winter squash, pumpkin, and parsnips are deep rooted.
Creating a balance between flowering plants and those valued for their foliage or fruits will add interest to your garden. No rule says all veggies or all herbs or all flowers need to be planted together. Monocultures dull the senses. I jazz things up by blending different plants. Watch for the opportunity to let color make a statement in your garden. I like to pair my flowering plants to complement my fruiting plants.
Interplanting a variety of plants is how the original cottage garden style evolved. Sectioning off gardens for specific types of plants was a luxury of the rich and leisured. You can apply the principles outlined here to container gardening as well. A patio tomato always looks better in combination with some flowers and herbs.