The monthly newsletter of Cliveden Gardens—August 2021

Colourful Clivedens summer splendour We spend weeks on a bedding changeover but its always worth the blood, sweat and tears when you hear the lovely comments our visitors make. Walking into the Long Garden and seeing the billowing purple cloud of Verbena rigida really lifts your spirits, you could almost be 800 miles away in Provence. Verbena rigida is fantastic for attracting bees, beneficial insects, butterflies and moths and a range of other pollinators. Walking through the swathes of rich magenta we have spotted a number of different butterflies including Red Admiral, Peacock,( below left) and Painted lady. Bees are loving the nectar rich plants we have in the Long Garden as you can see below (middle) the vivid orange Tithonia rotundifolia, this stunning member of the Asteraceae is native to Mexico and thrives in a hot, sunny spot. Rudbeckia hirta ‘Cherry Brandy’ (below right) is another magnet for the bees. This particular Rudbeckia is best grown from seed and treated as a half hardy annual and would not survive our cold, wet winters unlike some of its perennial cousins.

As we go from July into August the gardeners here at Cliveden move into hedge cutting mode. We have many miles of hedges to cut. We usually start towards the end of July with the hedge either side of the service drive. Theo, Alex and Lewis are cutting this as I write this afternoon. From there we cut the Laurel hedge from Hedsor towards the Long Garden. August is the month we work on the topiary in the Long Garden, always popular with the gardeners and the visitors alike. Visitors love to stop and chat about the topiary and of course we enjoy talking about all things topiary too. I won’t mention September and cutting the Parterre! Senior gardener James is starting to cut the areas of long grass we leave for the benefit of wildflowers and the associated fauna. This is another big job at Cliveden that will take several weeks to complete.

Must do Look through the bulb catalogues and order now for autumn planting. You can plant lots of lovely bulbs in pots and then just plunge into gaps you have in borders next year. The great plants woman Beth Chatto did this to great effect.

Upcoming jobs

Compiled by Mark Lamb, Assistant Head Gardener © National Trust 2021

Propagating Rhododendron By Lewis McLellan The humble Rhododendron, whether an exotic beauty (R. sinogrande) or an invasive weed R. ponticum); its importance to horticulture is immense. First introduced to the UK during the 16th Cen-tury, a single R. hirsutum (Alpenrose) was collected from the Swiss Alps. This of course did very poorly, and created the need for a more adaptable hybrid. After many years of selection and breeding, the modern Rhododendron has become a staple plant for landscapes and gardens. Creating more plants from one Rhododendron or Azalea can be a cost effective and rewarding process, plus they make excellent gifts. While some can be sown from collected seed, the resulting plants may not be true-to-type and could show different characteristics. The best way of creating identical copies of the original are either through cuttings or layering. However, taking cuttings from Rhododendron can be rather difficult, and may not produce the best results. The other method, layering, takes longer but produces higher success rates.

Air Layering – A Special Case Enter the McCabe Rhododendron (R. macabeanum); a large, old specimen located here at Cliveden. This particular one has been dying for the past few years, and is unsuited in its current location. Large-leaved Rhododendrons like this one need dappled shade to produce their biggest leaves and do well in plenty of organic matter. Sadly, this one has neither of those and is too large to relocate; so the only option is to propagate new plants from it. When layering a Rhododendron, low branches are used in order to reach the ground easily for rooting. But the McCabe Rhododendron has only one, high branch left, so this approach would be unfeasible; so I decided to opt for the ‘Air-Layering’ method instead. As with normal layering, the stem/wood of the plant is scored or wounded to induce new roots to form; then treated with rooting hormone & wrapped in a growth medium (moss, compost, etc.)

The main benefit of layering is that the cutting is still connected to the mother plant, which is less stressful to the new plant and gives more time for roots to develop. While this is not a common form of propagation, it is useful for saving prized plants that would otherwise be lost.

R. macabeanum in flower.

Prepared branch ready for wrapping. After 3+ Months, wound has formed a callus before new roots form.

Can you identify these common weeds that we all have in our gardens, they are certainly here at Cliveden!