It’s important to keep the soil around the basil’s roots insulated so use some type of mulch to topdress the soil. Pine needles, leaves or wood chips are all fine. A mulch bonus is that it discourages weeds as well.
As with most plants, a slow, deep irrigation is best. Give the basil an inch of water a week by using a soaker hose or drip irrigation. An inch of water is a lot more than it sounds. According to the folks at Fiskars, it takes a little over 3 hours to deliver 1 inch of water with a 50 foot, 5/8-inch soaker hose hooked up to a faucet with a flow rate of 1/2 gallon a minute.
If that’s too much to wrap your brain around, run the hose for half an hour and then use a gardening trowel to carefully dig a hole next to the basil and poke around to get an idea of how moist the soil is. If it’s dry, keep watering in 30 minute increments until you figure out how long to run the hose. Then do it once a week.
Fertilize the basil with calcium nitrate. Give it 1/2 pound per square feet of basil bed and sprinkle it on the soil about 2 inches away. Make sure you water well to soak the fertilizer to the basil’s roots.
Basil has a tendency to grow tall and skinny if you don’t take matters into your own hands. Pinch the growing tips off of new shoots while the plant is young. This encourages it to produce side shoots right below the pinched portion. The more shoots, the more basil leaves to go with the tomatoes you’ve got growing over there.
Photo courtesy: Schilling2/Flickr