Growing rosemary is easy as it will thrive in practically all soil types, as long as it does not become water logged. It prefers to grow in light sandy soil.
It is a hardy plant that can live for up to 20 years, with some varieties growing to a height of over 1 meter.
As rosemary is difficult to grow from seed and can take up to 3 months to emerge, quite often they do not materialize at all, so the easiest way is to buy small plants from a garden centre and grow them on. However, rosemary is easy to propagate from cuttings. Cuttings should be taken from healthy plants, with lots of new growth around May or June.
You can either use a sharp knife or tear a young shoot just below a leaf joint, the shoot should be about 7.5 cm. If you tear off a shoot you will have to trim the ‘heel’ to remove almost all of it. Pull the leaves off from the lower 4cm with your fingers.
Use standard potting compost to fill a 7.5 cm pot and insert 1 or 2 cuttings. Water the compost from below and cover with polythene, a transparent plastic will do or place in a propagator. Place the propagator or covered pot in a greenhouse or on a windowsill as the cuttings need a temperature of between 15c and 20c to root.
In approximately 8 weeks the plants will have rooted and can then be transplanted into individual pots until they have established a good root ball and then plant them outside in their final growing position.
Care is needed in selecting the right site as Rosemary does not like having its root ball disturbed. Add a handful of sand to the bottom of the hole, which should be slightly larger than the pot, place the plant on top of the sand and fill the hole with soil, gently firm into place. Make sure that the soil does not dry out until the plant has established by watering well.
Once established rosemary requires little attention, bar pruning in the fall to keep the plant a manageable, suitable size for your garden. If you live in an area that is prone to strong winds it is advisable to stake the plant.
Growing rosemary in a container is possible if you use a large, deep pot. Fill the pot with a mixture of sharp sand and potting compost and plant the rosemary making sure that the root ball comes below the rim of the pot. Water well during the summer months. As rosemary grown in containers is more susceptible to frosts it is advisable to move the container near to the house walls during the winter.