Growing raspberries can provide you with much enjoyment, as these plants produce fruit for as long as to 20 years. However, the Rubus spp. raspberry can be destroyed by insects, mold and viruses. Never plant your raspberries in areas where eggplant, tomatoes, potatoes and peppers have grown in the past four years since these plants transfer the Verticillium root rot genus, which attacks raspberries. Companion planting can help protect your raspberries from pests and diseases.
Although a member of the onion family, Allium sativum garlic produces 12 or more small bulbs or cloves, unlike the onion's one bulb. Garlic also has flat leaves, which differ from the onion's hollow, round leaves. Plant garlic near your raspberries to keep aphids and Japanese beetles away, allowing your raspberries to have a healthy growing period. Japanese beetles feed on raspberry leaves and stems while the larva feeds on the raspberry roots.
The decorative, attractive herb with yellow-green flowers and blue-green leaves called Ruta graveolens or common rue, originated in the Mediterranean area. It was used medicinally to treat a broad range of illnesses and conditions including hypertension and rheumatic pain. Rue now grows around the world and because it has some toxic properties, the University of Texas at El Paso & University of Texas-Austin Herbal Safety website recommends against ingesting it or applying it to your skin without consulting a physician. Plant rue next to your raspberry plants to help repel Japanese beetles and fleas.
Introduced to the U.S. from Europe, you can find Tanacetum vulgare common tansy growing wild around waste areas, along creeks, as well as roadsides. Old gardens also may have these fernlike herbs of the daisy family with their yellow flowers blooming in flat clusters on top of the plants. Since tansy has toxic properties, keep this herb away from pets. Plant tansy near your raspberries to help improve the fruit's flavor.
When the needles from Pinus spp. pine fall from the tree, they cause the soil to acidify. Raspberries planted nearby will benefit from this change and grow better, according to Sally Jean Cunningham, master gardener from Cornell Cooperative Extension and author of "Great Garden Companions: A Companion-Planting System for a Beautiful, Chemical-Free Vegetable Garden." Raspberries grow ideally in soil with a pH of 5.6 to 6.2, a slightly acidic soil that pine needles help create.