It seems to me that sweet basil is a sort of gateway herb for pre-gardeners. Many people I know who have never touched a tomato or squash plant in their lives and shudder slightly at the idea of deliberately covering their hands in dirt have nevertheless confessed to me at some point a secret desire to grow their own sweet basil.
And who can blame them? Though it's common knowledge among cooks that nearly all culinary herbs taste best when fresh picked, many common kitchen standbys, like rosemary, or thyme, retain a fair amount of their original flavor in dried form. But dried basil tastes nothing like fresh basil. Drying seems to transform basil into an entirely different herb.
And what with a meager plastic packet of chilled "fresh" basil leaves costing about as much at the grocery store as a live potted basil plant (and much more than an entire packet of basil seeds), if fresh basil is a regular guest at your dinner table, the economic argument for attempting to grow your own at home is practically unassailable.
With that in mind, I'm happy to offer a few quick tips for aspiring basil plant tenders. A warning, though: if your experience with this gateway herb goes well, before you know it, you'll be trying chives and oregano.
Tips on Growing Sweet Basil:
First, make sure you are picking the kind of basil you want: Sweet Basil is the kind generally used in classic Italian dishes, and has a sweet flavor and an aroma reminiscent of cloves. The varieties of basil used in Asian cuisine, including Thai Basil and lemon basil, have a more astringent, less sweet flavor, and can be quite citrusy.
The broad-leaved, bright green culinary basil you most often see in American grocery stores is Genovese Sweet Basil.
It has been my experience that basil grows much larger in the ground than in a container, but you can certainly get a healthy crop of leaves for a container plant if you take the right steps. Make sure you select a pot that truly large enough for your plant, and be prepared to transplant your basil plant to a larger container at least once during the growing season. A basil plant that is 4-5 inches high will do fine in a pot that contains about a gallon of soil; however, once a basil plant is 8-10 inches, it will need a container with a volume of at least 2-3 gallons.
If you are planning to grow your basil in a container, make absolutely sure you get your plant enough light. Ideally, your plant should live outside for at least a few hours a day. A sunny patio or balcony will do just fine.
If your basil plant will live indoors, place it near your sunniest window, and turn it often to make sure all of its leaves get exposed to the sun. For best results, you may need to improve the plant's access to light by by placing a bright indoor lamp near the pot.
If you will be planting your basil directly into the ground, select a spot with good drainage that gets at least 6 hours of good, strong sunlight -- the sunnier, the better. Sweet Basil in particular is is a Mediterranean cultivar that prefers warm weather, so make sure to wait to plant your basil until all danger of nighttime frost has passed, and the soil outside is quite warm. In Missouri, this generally means planting in May.
When your basil plant begins to produce flower buds, pinch them off.
I am serious about this. You may be curious about what the flowers look like (I will tell you: they are pretty). You may feel like pinching off flower buds is being mean to your plant. (Suck it up. You're planning to eat this plant, remember?) If you really want a nice crop of fresh shiny basil leaves, do what I say: pick off the buds. Preferably before they even start to bloom.
As soon as a basil plant starts producing flowers, it will put all of its energy into making huge, foot-long spikes of flowers, and then seeds. It will stop producing new leaves. The plant will grow rangy and stringy and the leaves that remain will start to lose flavor.
But if you pinch off the buds, your basil will produce whole new stalks full of leaves in an attempt to start over with the reproduction business, making a stronger, bushier, tastier plant. At the very end of the summer, you can let the plant flower for show if you like (or to create basil seeds you can save for replanting). The flowers are edible, and so are the basil seeds.
If you find yourself with a bumper crop of basil at the end of the year, just before the first frost, I recommend you make pesto. Or, alternatively, you can chop fresh, washed basil leaves coarsely in a food processor, press them into an ice cube tray, freeze them, and then store the cubes in a freezer-safe plastic bag, to be used whenever you want to add a hint of summer flavor to your food.