by Mary Anne Steele, Somervell County Master Gardener
When you are building a healthy garden, where you plant is as important as what you plant. Combining certain crops can help minimize disease and pest problems. Companion planting a strong scented herb can help repel certain pests. It is sort of like a “trap crop”, a plant that pests will like better than your harvest crop. Pests will congregate on the trap crop where you can ignore them, spray them, or pull the trap plant up and throw it away.
Some examples of combinations are:
Garlic and parsley next to roses to protect them from black spot, a fungal disease
Chives and garlic next to peas and lettuce to protect them from aphids
Radishes close to cucumbers to deter cucumber beetles
Rosemary, sage or thyme near cabbage to deter cabbage moth, cabbage bagworms and cut worms
Nasturtiums near broccoli to attract aphids away from the broccoli
Wild grapevines, planted on a fence or trellis at a garden entrance, will attract Japanese beetles. They love the grape leaves, and
the beetles can be pulled off and destroyed.
When you decide what to plant, consider what was planted there before. Growing a particular crop in the same spot year after year will encourage
a buildup of soil-borne pests and diseases. Keep records of what and where you planted.
Crop rotation has another benefit. It will help maintain the soil’s nutrient balance. Leafy and fruity crops are heavy feeders and use up nitrogen, while
root vegetables and herbs are light feeders. Peas, beans, and other legumes add nitrogen to the soil, but need lots of phosphorus. Follow a soil-building
crop with a heavy feeder crop and follow a heavy feeder with a root crop or a soil builder.