So I thought I would clarify a few things about herbs. Some herbs, such as sweet basil and cilantro are annuals. That means they will go to seed at some point during the season. When this happens the plants usually stop growing new leaves. Many things can trigger the plant to do this. Temperature, watering or disturbing the roots are a few of them. Whenever the plant is stressed they flower and develop seeds. This is the plants natural defense to ensure it will reproduce. If the seeds are left to develop and dry, they will drop and grow all new plants!
Other herbs that last longer are the perennial. That means they will grow for years and usually produce seed the next year, but the plant does not die. Rosemary, thyme, sage, and Thai basil are a few examples. Perennials should be cut back to just a few inches and re potted into fresh soil and fertilized (if in a container) at the end of the season and some can be split to grow more plants. If in the ground or a bed, cut back and fertilize. The plants will then start new growth all over again!
The best way to keep herbs growing and bushy is to use them. If they are not trimmed and used most herb plants will get leggy and woody stems. The best way to do that for basil is to cut it from the stem, not taking individual leaves. That goes for most herbs. Cut them, don’t just take leaves.
If you can’t use enough, find ways to preserve them. Dry them out till crumbly and store in spice jars in pantry. Some can be frozen. Make a pesto. That is just a few ways. I always have many of my own spice jars of herbs. They make great gifts too!