Plant of the Month May 2018


Published: May 31, 2018

Species:
Genus:



Posted on 31.05.2018 |
Updated on 19.06.2018 |
Added in Plant of the Month

Rosa banksiae

Is the rose really the queen of flowers? Long celebrated for colour, scent and shape, it has symbolised a wide range of emotions and behaviours, including debauchery, love and hope. The rose is one of the few flowers to have been mentioned in ancient writings and recorded in use for thousands of years. However it is perhaps only after Empress Josephine, with her taste for exotic plants, started growing roses in the Château de Malmaison during the 18th century,  that our Western appetite for cultivating roses was well and truly whet.


Rosa banksiae var. banksiae

The many beautiful hybrids that we grow today can be mostly traced back to the meeting of the Chinese species with our hardy but short flowering European roses. In fact, despite being so diverse, rose species are found only in Europe, North America and northern Asia. Grown for cut flowers, or cultivated as climbers, ramblers and shrubs, would it be possible to ever pick a favourite? For us, strong contenders are the varieties of the Lady Banks’ rose. Thornless and flowering earlier than most, these plants with a rich history, are ones that we would love to see more widely cultivated today.


Rosa banksiae var banksiae cluster

In 1807 William Kerr, a plant collector from Kew Gardens brought back a thornless, floriferous climbing rose. He named it Rosa banksiae (later known as Rosa banksiae var. banksiae) or Lady Banks’ rose, after Dorothea, the wife of the then Director of Kew Gardens, Sir Joseph Banks. This rose produced many small clusters of double white flowers and he had found it growing in a Canton garden in China. Thought at the time to be the first described, it was later discovered that the wilder species, Rosa banksiae var. normalis was already growing in Scotland, having been brought over to Megginch Castle from China at around 1796.


 Rosa banksiae var. normalis

Other forms were later produced or discovered, notably Rosa banksiae var. lutea which produces a yellow double flower, and was introduced to the UK from China via the Calcutta Botanic Garden some time before 1824. This is the hardiest of the lot, the Lady Banks’ roses admittedly performing better in warmer climates and requiring sun to ripen wood, which helps prevent frost damage. Rosa banksiae var. lutea is thought to be an old Chinese garden hybrid. For unusual, blue hips produced after flowering, it is also worth mentioning Rosa banksiae f. lutescens as an interesting variety for the garden.


Rosa banksiae var. lutea

The easiest propagation method for Lady Banks’ rose is to take hardwood cuttings in the autumn. This guarantees that the same plant produced, is that of the parent that it is taken from. Make cuttings approximately 30cm long, ideally the thickness of a pencil, and with the bottom cut below a node. Place cuttings in a long, narrow pot (such as a long tom) in fifty percent coir and fifty percent grit and sand. Place the bottom 20cm of the cuttings in the medium, with the tops sticking out. Firm in and water, then leave in a cold frame or a sheltered spot outside. Occasionally check that the medium has not completely dried out and water if needed. When the buds start to break and produce new growth in spring, this is a sign that the cuttings have taken. Lifting the pot and looking underneath for roots is another obvious sign of propagation success. Once ready, pot up and grow on until plants are big enough for planting out, probably the following spring.


Rosa banksiae var. normalis at Wrest Park

Aphids are the main pests suffered, such as is with most roses. If only a few aphids are present, let the birds take care of them. If the problem is severe, spray with a soap-based product or jet off with water. Plant the rose in humus-rich soil with a support to climb. Grow in a sunny position and keep moist all summer. If the plant starts getting too big, prune back in autumn.  


Rosa banksiae var. lutea on Yew

Perhaps we have so many highly fragrant, large flowered climbing roses to choose from these days, that the Lady Banks’ rose is a less popular choice than it once was. It is not a flashy plant, but occasionally we spot it brightening up an area, such as growing up a Yew tree at Waterperry Gardens in Oxfordshire, climbing the back of the school at Kew Gardens, or even accompanying Wisteria at the Alhambra in Spain. Where there is a sunny spot, perhaps it is still worth making space for this lovely lady of China in a few more gardens elsewhere.


Rosa banksiae var. lutea at the Alhambra