Tamarix is a plant with Biblical connections, but not many people are that aware of it because it is a tree or shrub that tends to be found beside the seaside. This is because they thrive in the salt and moisture. But they can still be grown in an inland garden and are even seen growing as street trees.
They have a slender form, with arching branches covered in fine foliage and plumes of tiny pink flowers in early or late summer. The leaves are small, resembling scales or needles, and they have salt-excreting glands. This explains why they do well next to the sea and how they limit their competition. Their ability to accumulate salt and then excrete it prevents less salt-tolerant plants from growing around their base.
There are 54 species of Tamarix growing across Europe, Asia, north Africa and India, but the few that we grow in the UK are mainly from the Mediterranean region. T. gallica is from south-west Europe but it has become naturalised along the English coastline. It thrives on saline soils and it is extremely useful as a windbreak.
It is also the tree that is credited with saving the Israelites from starving in the desert. The sweet, sticky resin of the tree attracted insects, which turned the sap into honeydew, and this fell to the ground overnight. When the Israelites saw these golden dewdrops, they cried: "Manna," meaning: "What is it?"
and fed on it every morning. This explains the origin of the phrase "manna from heaven".
Other popular species include another Mediterranean and Asian native, T. tetrandra Award of Garden Merit (AGM), which also makes an excellent coastal plant. It is one of the earliest to come into flower, in the late spring or very early summer. The Russian species T. ramosissima is also a favourite. It has blue-grey leaves and flowers in late summer. It has produced several attractive varieties, including 'Rubra' AGM, which features darker-pink flowers, as well as 'Pink Cascade'.
On the coast, the trees are able to use salts in the soil to reduce transpiration so they are happy in well-drained soils in full sun. But inland they will need somewhat moister soils to do well. Young plants can be cut back hard to encourage well-branched forms - in fact, they can produce masses of flowers if they are treated like a buddleia and cut back in late winter. They can continue to be cut back as they mature.
Some flower on twigs of the current year's growth and others on the woody branches of the previous year. Therefore, early-flowering species should be pruned straight after flowering and the rest in late winter/early spring.
What the specialists say
- Robert Vernon Snr, owner, Bluebell Arboretum & Nursery, Derbyshire
"I am equally keen on both T. ramosissima 'Pink Cascade' and T. tetrandra AGM. They are both reliable and very hardy but they need excellent drainage.
"They may be grown as a small spreading tree, in which case they often start off growing chaotically but eventually establish into a cumulus cloud shape - very attractive if you have the space - or they may be pruned hard in spring, rather like a buddleia, which results in a much 'tidier' plant of upright habit with lovely sprays of flowers in early or midsummer, according to species. Both species complement each other by flowering early or later in the season.
"I was fortunate enough to travel to Tibet a few years ago where, among other places, I visited the astonishing 13-storey-high Potala Palace, ex-home of the Dalai Lama. There I saw Tamarix being used as thatching and it brought home to me what a very hardy plant this is. The palace is 14,000ft above sea level, sometimes very hot in summer and bitterly cold in winter, but, above all, usually very dry. The climate there is almost that of a desert and I quickly realised why Tamarix aren't always at their best in the heavy, often wet, clay soil of our Derbyshire arboretum."
- Mike Glover, managing director, Barcham Trees, Cambridgeshire
"There are very few trees that thrive in coastal conditions but Tamarix is one of them. Barcham stocks 478 varieties of tree and we can only recommend eight of these for coastal sites, so Tamarix is a valued genus in our range.
"We sell T. aestivalis, T. gallica and T. tetrandra, and all of these will thrive in very sandy soils and are very tolerant of exposed windy locations. They are not keen on being planted on shallow chalk though. Being small trees, they are ideal for gardens where space is at a premium - and of course the profuse flower is both pretty and unexpected."
- Andrew Wilson, garden designer, Wilson McWilliam Studio, London
"Tamarix is an underused plant. Most people regard its pinkness as a negative. But I rather like the combination of the glaucous foliage with the pink that creates a diaphanous and dreamy transparency.
"It's a Mediterranean plant and is often used in the UK in coastal situations because it tolerates salty winds. In urban gardens and especially in smaller spaces it's a winner because it casts so little shade. It can be grown as a small tree and reaches up to 6m or so with a similar spread if left to its own devices. However, it can be treated more like buddleia and cut back quite hard after flowering to encourage more prolific plumes the following year - similar to pollarding. Their soft and feathery nature works well with grasses and perennials.
"They work well in gravel garden settings and provide an ideal specimen for dry gardens, often becoming gnarled and twisted as they mature. There are two main species commonly available - T. tetrandra AGM and T. ramosissima.
"T. ramosissima 'Rubra' is a darker form that has been awarded an AGM from the RHS. They will still work in moisture-retentive soils and don't need to be used solely in coastal conditions."
Species and varieties
- T. gallica is a small, deciduous tree that produces pink flowers in the summer. Originally from south-west Europe, it has naturalised along the English coastline. Height: 10m.
- T. parviflora is a shrub or small tree that has slender, dark-purple branches that are usually arching. These are covered in plumes of light-pink flowers. Similar in habit to T. tetrandra. Height: 5m.
- T. ramosissima (syn. T. aestivalis) is a shrubby species originating in Russia that has arching branches covered in feathery, blue-grey leaves and panicles of tiny pink flowers in the late summer. Height: up to 8m. Spread: 5m.
- T. ramosissima 'Pink Cascade' is a popular shrub or small tree with arching branches covered in sprays of tiny, rich pink flowers in late summer and early autumn as well as slender, light-green leaves. It is a valuable windbreak in warm, coastal areas, thriving in any well-drained soil, except shallow chalk. Height: 6m. Spread: 5m.
- T. ramosissima 'Rubra' AGM (H4) is a hardy shrub with arching branches, covered in rosy red flowers in late summer and early autumn. Height and spread: 5m.
- T. tetrandra AGM (H4) is a vigorous large shrub or small tree. It is similar to T. ramosissima 'Pink Cascade' but its plumes of pale-pink flowers come earlier in the year, appearing in late spring or very early summer. Its branches are almost black in colour. Ideal for growing in flowering borders, woodland areas or windy, coastal positions. Height: 6m. Spread: 5m.
Thank you to Floramedia, which supplied the images for this article from its photo library