Let's look at the class "herbs" more closely.
First thing to consider is that they are all weeds. If you ever tour the Med. region you'll find most of our common herbs growing wild on the hillsides.
Many of them: rosemary, sage, tarragon, lovage....are herbacious perenials that do not require much care. They are semi-arid in nature, and need little in the way of extra nutrients. Once you establish them you'll have them forever. Sage is an exception, in that in tends to run out after two or three years.
Others are perenials but not herbacious. The mints, and everything in the mint family (you can always tell one of them because the stems are square) are perenials, usually vineous or at least trailing. They, too, can survive nicely with little help from the gardener.
Some, such as parsley and sorrel, are biennials. They produce only leaves, the first year. The second year their goal is to go to seed (and, in the case of parsley, produce large roots). These usually require only watering, the first year, but benefit from extra nutrients the second year.
And then there are the annuals, such as basil. The annuals tend to be more tender, and require better care than the others. But even with them, nutrients in the ground and water from the sky are enough for survival.
However, all this applies to plants that are growing in the ground, in zones they are rated for. Once you put them in pots and other containers, all bets are off due to the nature of container gardening.
Because 1. they are elevated above ground, and 2. contain a limited amount of soil, containerized herbs, like other potted plants, require greater care than those in the ground. They have to be watered more often, because containers dry out exponentially faster than the ground around them. And, because you are watering frequently, the nutrients in the small block of soil tend to leach out. Thus, you have to periodically replace them.
In addition, what the plant needs for survival, and what we expect from the plant, are not always the same. With herbs we're looking for a steady supply of leaves & stems to use in our cooking. In order to encourage foliar growth, we therefore fertilize appropriately. And that means nitrogen.
As to growing indoors, all herbs do well under fluorescent lights. That's one way we grow them over the winter. All you need are cool-white bulbs, and a way of adjusting them so they are only a couple of inches away from the top of the plants.
One more thought. For those who can't find plants or seeds locally, many herbs---particularly the herbacious types---readily grow from cuttings. Which means the herbs you buy in the supermarket, in those plastic clamshells, can be turned into plants.
This year, for instance, I started oregano, majoram, tarragon, mint, and thyme that way.  |