Many people grow herbs for personal use in gardens and window boxes, but growing herbs commercially on a larger scale can also provide a nice side income--or can even be a full-time job. Herbs are easier to care for than many other garden plants; some herbs, especially rare or medicinal herbs, can net a high profit margin. Growing herbs commercially is about a lot more than just gardening; however, you must be prepared to put a lot of work into the business side of it, too.
Decide what herbs you would like to grow. Will you be growing culinary herbs such as basil, parsley, dill and rosemary or will you be growing medicinal herbs such as echinacea, borage, calendula and chamomile?
Consider your market. If you plan on selling herbs locally, visit the farmer's market to see what other growers are selling. If there's nobody selling fresh lemon grass, for instance, perhaps that is a niche you could fill. Call local grocery stores and restaurants and regional and national distributors to ask if they have any fresh or dried herb needs.
Talk to your local health department to find out what is required for selling culinary or medicinal herbs. Most likely, your operation will need to be inspected for cleanliness and you will need to obtain a business license or complete other paperwork. If you would like your operation to be USDA Certified Organic, that program requires additional record-keeping and paperwork.
Grow your herbs. In temperate climates, you will be able to grow and harvest herbs outdoors year 'round. In cooler climates, you may want to invest in a greenhouse to greatly extend your growing season. Take into account how much you will need to grow in order to make a profit and how much you can manage yourself without hiring help.
Invest in whatever processing and packaging equipment you might need. If you'll just be selling your herbs at the local markets and to a few restaurants, your equipment needs may be as simple as pruning shears and a roll of plastic bags. For drying herbs, you will need a commercial dehydrator. National or regional distributors might have their own specific processing and packaging requirements.
Track your income and expenses on a spreadsheet; save receipts and as much documentation as you can. You will need meticulous records come tax time. Check in with the IRS for the specific requirements of a small business.
You will also want to write up a business plan. Plan what you want to grow, when it should be ready to harvest, how you will market it, how much you will charge for it and what your anticipated expenses will be. Revisit and update your business plan every year. Your local Chamber of Commerce or the Small Business Administration can provide you with the necessary forms for a business license and can help you with any other paperwork necessary for growing herbs commercially.