Rosemary is a popular culinary herb with a range of other uses and is a popular plant for herb gardens in the UK. In wetter and cooler regions of the UK, and for exposed gardens, it may be easier to grow rosemary in a polytunnel, undercover, where this Mediterranean herb can thrive in warm, dry and sheltered conditions.
Rosemary can be grown from seed, which should be sown in around May, though in the UK it is far easier and more usual to grow this herb from small plants, or rooted cuttings, which are available in most garden centres and plant nurseries. Most home growers will only need one rosemary plant as this intensely flavoured herb is only used sparingly in the kitchen.
Rosemary is fairly drought tolerant and so you should water only sparingly and make sure that you do not overwater, especially during the colder months. You can grow rosemary in either a container or direct in the soil in your polytunnel, though during hard winters, you will need to provide a little extra protection for your rosemary in many parts of the UK. Raise container grown plants onto pot feet to guard against waterlogging and, if you have grown rosemary in a polytunnel bed, apply a thick mulch to protect plants in the ground. In the coldest parts of the UK, you may also have to cover the branches of a young and tender rosemary plant with horticultural fleece.
To keep rosemary plants healthy and well-shaped, it is a good idea to trim back the stems after the blooms fade. If you do not do so the plants can have a tendency to become leggy.
Rosemary is said to be a useful companion plant for brassicas, carrots and beans as it can help to deter a wide range of pests that can damage those crops. Rosemary will grow well alongside other drought-tolerant Mediterranean herbs such as thyme.
Regularly picking the needle-like leaves and tips from your rosemary bush should help to keep the plant well-shaped and productive. Simply take the tips as required throughout the year. Rosemary can be used fresh in recipes, in a bouquet garni or dried for later use. Rosemary is also used to promote memory and has a range of herbal remedies associated with it as well as culinary applications.