Herbs are low-maintenance plants, but they still require repotting occasionally.

Herbs add fragrance and beauty to both indoor and outdoor living spaces. Flavorful herbs such as thyme, parsley, and rosemary, make fantastic additions to kitchen windowsills, back-porch steps, and patios. Growing herbs in containers is a simple and often enjoyable alternative to herb gardens, which often require the luxury of space and soil. While herbs require little maintenance, repotting is necessary in some instances, such as after you initially purchase them. When you buy herbs at the supermarket or greenhouse, they often come in a tiny pot with mostly all root and little soil. Herbs cannot grow well in these conditions, which are only meant to temporary accommodate the plants. In addition, potted herbs eventually outgrow their current containers and require larger pots to suit their growing needs. Fortunately, repotting herbs is a simple task that only requires basic gardening supplies and a few minutes of your spare time.

Types of Pots
It doesn't really matter what kind of pot you use as long as it is no more than two inches deeper than the existing pot the herb plant is currently in. Pots too large allow the roots too much space to grow and also hold too much water, which can lead to root rot. The other important element to look for in a pot is its drainage system. Herbs require an adequate, built-in drainage system to prevent their roots from staying too moist and rotting. Round or square pots work best, and square pots are ideal if you're planning on repotting several herbs in on large pot. You can plant up to four herbs (one in each corner) of a larger, square container.

Potting Soil
Use a quality potting soil from a nursery or garden supply company to ensure the herb receives all of its nutrients. Although it is tempting (and cheaper) to dig up some dirt from your backyard and use it for potting soil, ordinary garden soil is way too dense and tends to dry out too quickly for this purpose. A premium potting soil blend for both outdoor and indoor plants works fine for repotting herbs. You can also mix a small amount all-natural organic fertilizer into the potting soil, if you wish. Once you've chosen the potting soil, put it into the new pot. Fill the pot no more than half full of potting soil, slightly bringing it up the sides of the pot. Gently press the soil to help it stay in place, and then lightly, but thoroughly, moisten the soil with water.

Root Ball Preparation
Before repotting any herb, it's important to carefully prepare the plant's root ball. Preparing the herb's root ball encourages the plant to grow properly. If the herb is rootbound, it's always helpful to thoroughly water the root ball prior to repotting. You should have no trouble removing the herb from its existing container, since root-bound plants typically slip out their pots with ease in one piece. If the plant is being stubborn, invert the container while using your hand to support the top of root ball. Shake the container in a downward motion to coax the root-bound herb out of its pot. Once you have removed the herb from its current pot, loosen the root ball to encourage proper nutrient absorption. Make three to four vertical cuts up the sides of the root ball (about a third of the way up) and then use your fingers to gently untangle the bottom of the root ball. You may also need to trim the roots if you discover a thick tangle of root tissue. To prevent the herb plant from becoming strangled with its own roots, cut through any roots growing in a circular pattern.

Repotting
Once you have prepared your herb plant's root ball, it is finally time to repot the plant. Gently place the prepared plant in the new container, which you have already prepared with new potting soil (above). Make sure the plant is not sitting any deeper in the new container than it was in the original. Fill the empty spaces around the plant with potting soil until the container is full of loose soil. Gently, but firmly, press the soil firmly around the root ball as you fill in the container with the potting soil. Finally, tap the sides and bottom of the pot to help distribute the soil evenly around the root ball. Once you are finished repotting the herb, moisten the roots with water to promote new growth and encourage the plant to establish itself in the new container. You may notice an improvement in the plant's health within as little as 24 hours.
Repotting herbs can give them a new lease on life, especially if they are rootbound in their existing pots. Using proper repotting techniques ensures your herbs are able to absorb nutrients, grow freely, and thrive in their new containers. Since herbs are continuously growing plants, you will likely need to repot the plant in the future to accommodate its growing roots.