Star jasmine (Trachelospermum) is native to tropical and subtropical regions of Asia. In Europe, this evergreen climbing jasmine shrub grows particularly well in the Mediterranean region. Be careful not to confuse star jasmine with true jasmine (Jasminum officinale), as despite having quite similar characteristics, they don’t even belong to the same plant family - Star jasmine belongs to the dogbane family (Apocynaceae) and poisonous, whereas true jasmine is a member of the olive family (Oleaceae). Ancient Egyptians used the blossoms to perfume their bath water, and in China, petals were used to flavour black or green tea, but made from the true jasmine, being exotic and not toxic!
Star jasmine has small star-shaped flowers with a distinctive sweet fragrance, and is popular with bees and other pollinators. It doesn’t do well in direct sunshine and can get ‘sunburnt’, so some shade is essential. Changes in temperature may affect blooms either way – the cold can slow down growth and delay flowering, and too much heat may halt blooming altogether. It's a delicate balance, where even a few notches on the scale can change everything.
They are perfect for growing up a wall or fence, and high climbers will benefit from the support of a trellis or a wire framework. As your plant grows, gently tie up new growth, just tight enough to allow for natural movement and prevent damage to the stems.
Use shade cloth or strategically placed garden structures or taller plants nearby to shield your plant from the harshest afternoon sun. And don't forget to water; deep, infrequent watering encourages strong root growth, helping your plant stay hydrated. Planted somewhere warm but sheltered, perhaps near your seating area, will enable you to enjoy their exotic perfume.
How to prune jasmine climbers
Firstly, it is recommended to wear gloves when pruning star jasmine, as its milky sap is toxic and can irritate the skin. It is renowned for its long-lasting foliage and floral display, and to ensure that your climbers continue to grow and produce as many flowers as possible, pruning at the right time is essential. Timing is critical, whether in pots or in the ground, and although caring for star jasmine is relatively simple, one important job to get right is pruning - doing it at the wrong time can damage your plant and reduce flowering the following year.
Trimming should be done after the main flowering period in late summer to control size and shape, and to encourage bushy lateral growth. By August and September, you will see many long, whip-like stems that can appear slightly messy. At that point, it is time to have a tidy-up.
Flowers bloom on the previous year's growth, so pruning in late summer gives it enough time to produce new stems that will harden off before the cooler months. Future flowers will bloom on these stems that grow in late summer and early autumn, so getting the timing right is vital.
Take a good look first
Before even taking hold of your secateurs, step back and inspect its shape. It is always best to prune with intention, so decide the desired shape and scale for your jasmine to begin with.
Remove dead or damaged stems, which will help to maintain a healthy plant with a natural shape, and then prune long stems down to 30cm to 60cm, cutting just above a leaf node. They are known for their moderate to fast growth, growing up to a massive 60 cm each year.
Height of the plant
Keeping your jasmine lower growing is optimal, and growing one high along a fence or garden wall might be your intention, but still prune your jasmine so that it is contained and compact. You do not have to worry about cutting back too hard, so long as you prune above a leaf node, and you will see fresh new shoots in the coming weeks.
A little about companion plants: lavender and rosemary repel pests, and geraniums attract pollinators, complementing your jasmine’s growth. But avoid mint and ivy; they compete with Star Jasmine for resources.
Marilyn writes regularly for The Portugal News, and has lived in the Algarve for some years. A dog-lover, she has lived in Ireland, UK, Bermuda and the Isle of Man.