Border Landscaping to Prevent Bugs

Japanese Beetles

• Strongly scented plants, such as garlic (Allium spp.), rue (Ruta graveolens) and tansy (Tanacetum vulgare) repel Japanese beetles. These destructive bugs are attracted to knotweed (Polygonum spp.), a perennial flower that blooms with red, pink and white flowers from summer through fall. Plant a border of knotweed to attract beetles away from other plants.

Aphids

• To repel aphids, choose pungent species, including garlic, basil (Ocimum basilicum), chives (Allium schoenoprasum), coriander (Coriandrum sativum), dill (Anethum graveolens) and petunias (Petunia x hybrida). Aphids are drawn to nasturtiums (Tropaeolum majus) and feverfew (Tanacetum parthenium); plant a border of these annuals to draw the pests away from other plants.

Whiteflies

• Whiteflies feed on foliage, leaving behind a sticky substance that then grows black mold. Repel these pests with a border of marigolds (Tagetes spp.), nasturtiums, tansy and basil.

Tomato Hornworms

• Tomato hornworms, large, bright-green caterpillars that feed on tomato foliage, are deterred by strongly scented plants. Plant a border of basil, borage (Borago officinalis), calendula (Calendula officinalis) and marigolds to repel these destructive insects.

Nematodes

• Nematodes, microscopic worms that live in the soil, feed on plant roots and cause a great deal of damage. They are repelled by marigolds, dahlias (Dahlia spp.) and chives.

Cabbage Worms and Butterflies

• As their name suggests, both the larvae and adult forms of these insects are attracted to plants in the cabbage family. To keep them away, plant a border containing scented herbs including mint (Mentha spp.), oregano (Origanum vulgare), thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis), sage (Salvia spp.), dill, chamomile (Chamaemelum nobile) and lavender (Lavendula angustifolia). They are also repelled by hot pepper plants (Capsicum spp.), geranium (Pelargonium spp.), hyssop (Hyssopus officinalis) and nasturtiums.

Mosquitoes

• While they may not damage your landscape plants, mosquitoes irritate humans, and some carry disease. Certain plants contain oils and scents that repel mosquitoes. Lemon grass (Cymbopogan nardus) grows as a decorative grass and contains mosquito-deterring essential oils, as does a geranium-citronella grass cross called Vanieeni or citrosa (Pelargonium citrosum “Vanieenii”), which repels mosquitoes with its citrus aroma. Lemon thyme (Thymus x citriodorus) also has a citrusy, mosquito-repelling scent. However, these plants work best when their leaves are crushed to release fragrance.