Basil
I am sure most people are familiar with the fragrant, tender herb that is Basil. Genovese Basil, in particular, has large shiny green leaves and is the best basil for Italian-style and tomato-based cooking. It thrives in summer conditions, and because there is no need to wait for fruit to ripen, you can plant it basically any time of year that doesn’t have frost.
Climate
Basil is a tender annual and is not frost tolerant. It prefers that nighttime temperatures don’t drop below 50°F. During the cold season, Basil can be grown indoors in brightly lit windowsills, or in kitchen countertop growing setups that use artificial light.
Sun
Basil likes full sun, so make sure to plant it in a spot in your garden that receives at least 6 hours of light. Even better if it can get 8 hours!
Soil
Like most veggies and herbs, Basil prefers rich, loamy, well-drained soil. It also prefers soil temperatures higher than 50°C. Basil does particularly well in raised beds for better drainage. It prefers a pH range between 6.0 and 6.5, and therefore can share a bed with most other summer veggies, especially tomatoes.
Fertilizer
You don’t want to overdo fertilizer because it can push leggy soft growth, but you don’t want to be stingy with it either as you do want lush foliage. A good, balanced, slow-release fertilizer once a month or every other month will do great.
Water
Water Basil regularly. It likes moist soil, but doesn’t like soggy feet so don’t overdo it. Don’t let it wilt often as this can invite disease. You also want to make sure to avoid getting water on the leaves. This can also cause disease, and you don’t want fugal spores in your pesto.
Pests & Diseases
Basil is prone to fungal growth on the leaves, which is unfortunate because it’s the leaves that we have interest in eating. The best thing to do is avoid getting the leaves wet. Fusarium wilt looks like regular wilting, but it won’t recover with water. If you have a wilted plant, carefully remove the whole thing from your garden. Throw infected plant material in the trash, not the compost. Other fungal diseases, like black spot and grey mold, can be cut off with clean tools and carefully removed. Be mindful not to spread the disease, and be sure to clean your tools with Lysol, bleach, or 70% ethanol products between cuts. Downy mildew is a new basil disease that yellows the leaves and looks slightly fuzzy on the underside of the leaves. This usually results from overhead watering, so let the area dry down and remove badly infected leaves.
Basil can also have problems with thrips and aphids. Insecticidal soap treatments are good options here. Slugs can be trapped using slug and snail traps or by setting bait out around the base of the plant.
Because we will be eating the leaves of the plant, we really want to avoid most fungicides and insecticides for pest control on Basil. Clean growing practices are your best bet to avoid problems in the first place.
Maintenance
Since we want to harvest the leaves of the Basil plant, we want to encourage as many branches (and therefore leaves) as possible. When a stem has between 6 and 8 leaves on it pinch it back to the first pair of leaves on that branch. This branch will now grow more branches, and create a fuller, bushier plant. Repeat every time a branch has 6-8 leaves. Add all the leaves from your trimmings to yummy tomato sauces, pesto, and summer salads. After 6 to 8 weeks, cut out the center flower stem, this encourages more branches, and more leaves. If you ever see flowers starting to come in, cut those off. Again, we want it to put its energy into leaves, not flowers and seeds.
If you want to make a lot of pesto, it is best to plant multiple plants so your regular pruning will result in enough leaves for a good-sized batch. Use smaller harvests to mix into tomato sauces, sprinkle on top of bruschetta, liven up a green salad, or chop into egg and potato breakfast dishes. Sweet Genovese Basil is super versatile, and you will find plenty of ways to use up your lush green leaves.
