Gardening Articles: Edibles :: Herbs
by National Gardening Association Editors
Types of Basil
Caring for Basil
Basil needs a steady supply of moisture and warm soil temperatures to produce well, so you have to play a balancing act with mulch. In cool areas, delay mulching until the soil temperature has reached the mid-60s. Where summer really heats up and soil loses moisture quickly, you can add mulch sooner.
This heat-loving herb is susceptible to even mild frost; harvest the remainder of your crop if temperatures are predicted to dip into the 30s.
Basil has few pests, but occasionally generalist pests such as aphids, flea beetles, and Japanese beetles will feast upon it. Rinse off aphids with a garden hose. To prevent beetles from munching, cover the crop with fabric row cover. If slugs are a problem on new transplants, try a barrier of copper flashing.
Diseases are more of an issue for basil-lovers. Fusarium wilt of basil, first identified in the early 1990s, arrived via infected seed imported from Italy. Symptoms include sudden wilting and leaf drop, accompanied by dark streaks on the stems, usually in weather above 80°F. If you notice these signs, quickly dig up the infected plant, along with all soil around the roots, and discard it. If part of your garden becomes infected, avoid spreading the disease by moving soil around on your tools or tiller, and consider growing your basil in containers. You might also try a fusarium-resistant variety, such as Nufar.
Basil is also susceptible to a few bacterial rots that show up on stems or leaf clusters, usually in cool, wet weather, often late in the season. Keys to control include planting in well-drained soil, spacing plants so they dry off after rain, and removing infected plants from the patch.