The carom plant is an Indian herb that is also known as bishop weed, ajowan, and Trachyspermum ammi. It can grow both outside in the herb garden and indoors. If you live in a tropical area, you can grow this herb as a perennial but just like mint, make sure you want the plant in that area. On the other hand, if you do not live in a warm environment year round but still want to grow this herb outside then you will be growing the carom plant as an annual. The other choice is to simply cultivate it as an indoor plant.
While you may think that you can simply find this herb in a seed catalogue and order but it is not that easy. The simplest solution to this problem is to buy fresh plant from an Indian grocery store or ask if you can have a sprig at an Indian themed restaurant.
Once you have your sprig, you can process your start like you would with mint. Cut the start at an angle and dip in a rooting hormone. In a shallow container, add an all purpose potting medium and mist with water until evenly moist.
Next, take a pencil and make a hole in the soil. Place your prepared cutting in the hole and move the soil around the cutting. Repeat this process until you have planted all your prepared cuttings. Mist the soil surface again. Place the cutting in a sunny location, monitor the soil moisture, and check for the rooting progress in about two weeks. This is not done by pulling up the cutting instead gently tug on the cutting. If you feel resistance then you have roots, which means you are ready to transplant.
If you want to plant outside, there are only two requirements that this plant is picky on. The first one is sunlight. This herb requires full sun. The second is the moisture. It does well in a soil that is kept evenly moist. Beyond these requirements, the carom plant can be planted anywhere but as stated before it can take over like mint. While it will probably be grown as an annual, the quick growth can smother out plants before a killing frost kills it.
Another idea is to add this herb to your indoor culinary garden. To control the soil moisture and keep it from becoming too wet always plant this herb in a container with a drainage hole.