Here are some of our ‘Plants of the Month’ chosen for you by our Head Gardener, Rod Milne, who is always keen to share his passion! A new plant will be added each week throughout the month.
The Golden Oat Grass
Ornamental grasses have a fascinating habit of falling in and out of fashion with gardeners. Over the last ten years they have definitely been ‘in’ again and have formed the backbone of a new style of planting adopted by many garden designers which in turn has led to their renaissance amongst other gardeners. In this style grasses provide grace, elegance and unity in the midst of a complex matrix of flowering perennials.
Thankfully certain good plants are free from the rise and fall of gardening fashion and will always be cultivated in gardens. One such plant is a beautiful grass called Stipa gigantea, aptly known as the ‘Golden Oat Grass’. From a mound of evergreen, linear leaves rise fantastically elegant two metre tall flower stems. The flowers are faintly tinged purple but by late July the seeds have fallen and the stems ripen to a golden colour. In a summer breeze the stems shimmer in the light. The tall flower stems have a transparent quality which allows easy viewing of what lies beyond.
The ‘Golden Oat’ is very easy to grow and enjoys a sunny position with well drained soil. To keep the plant looking tidy the old flower heads can be cut off low to the ground in the autumn. Here at Picton we sometimes comb the mound of leaves with a rake to remove some of the old dead leaves. It is best planted so that it can be viewed with the evening light behind it.
The Australian Bottlebrush
We are lucky here in Pembrokeshire and in other mild part of the United Kingdom to be able to grow plants from all corners of the globe. This includes ‘Australian Bottlebrush’ or Callistemon; a genus of evergreen shrubs in the myrtle family.
The flowers do resemble a soft frilly bottlebrush and they are devoid of petals, however a very colourful show is provided by the mass of stigmas and stamen. The type most often seen in gardens is the red-flowered Callistemon citrinus, but in the Walled Garden here at Picton we have a large shrub (2m tall) of the pale yellow flowered Callistemon salignus. Both types are very much loved by bees and other nectar loving insects which spend ages crashing around each brush.
Coming from the east coast and south west of Australia, Bottlebrushes are not considered to be very hardy in Great Britain, however, given a sheltered location in full sun they will thrive with only minor damage being sustained in cold winters. They are tolerant of coastal locations and massively drought tolerant. After flowering, seed pods form and will remain unopened on the plant until stimulated to open when the plant eventually dies or fire causes release of the seeds – the latter being an uncommon occurrence in British gardens. Should seed be desired, a hammer will replace this environmental adaptation.
Beautiful Bearded Irises
Iris have striking, complex flowers composed of inner, often vertical, petals and flattened outer ones. This flower shape has evolved so as to provide a landing platform for pollinating insects. It is a vast and diverse family, with many types useful to gardeners such as the early flowering alpine bulbs, for example, Iris reticulata and also the many varieties of herbaceous perennial such as the lovely varieties of Iris siberica.
In flower at the moment is another type which is the most spectacular and has the biggest flowers. This group is known, rather unromantically, as bearded rhizomatous Irises due to the beard-like hairs on the flattened petals and the fattened stems or rhizomes that creep along the ground and serve as a storage organ for the plant. Within this group there are a great many different varieties varying in height from about 15cm to about 1m tall. The come in a huge range of colours and some also have enormous blousy flowers which are easily spoiled by rain.
This group of Iris all share many common features. They have flattened pointed leaves of a blue-green colour that are arranged in a fan shape, above which are held the flowers, well clear of the foliage beneath. They all love the sunshine and will thrive in every bit that Pembrokeshire has to offer, but should be grown where they will not be too cramped or shaded by other plants. They also require good drainage but, when happy, can be left for many years without requiring further care. If you wish to divide a clump this should be done about a month after flowering and the parts that are replanted should be left with the thick rhizome slightly above the soil surface so it can soak up the sunshine.
Himalayan Blue Poppies
Himalayan blue poppies are some of the most alluring of all garden plants. Being of extraordinary beauty, coming from high in the Himalaya Mountains, and being demanding in their cultivation requirements makes them a romantic challenge for many passionate gardeners.
Himalayan Blue poppies are in the same genus as the pretty Welsh poppy (Meconopsis cambrica) which, if you are lucky, will carelessly seed around your garden and require no maintenance. Blue poppies however require cool growing conditions with lots of moisture but good drainage. They really dislike hot dry summer weather and anything resembling drought which will rapidly reduce the vigour of the clump. In Scotland and Ireland where the summer temperatures are lower and the rainfall often greater, they flourish and are long lived and easy to grow. After purchasing a plant from a nursery or after raising them from seed, it is very important to prevent them flowering for the first year by removing the flower stem. This is very heart wrenching to do but for the first year the plant must be allowed to concentrate its efforts on building up growth and multiple shoots. If they are allowed to flower that first year they invariably die, having no energy to carry on after flowering. Here in Pembrokeshire great care must be taken in finding the right spot for them but once found they are relatively easy to keep growing.
With the right growing conditions and when a strong vigorous clone is found, such as Meconopsis x sheldonii, the effect is breathtaking when the delicate looking pale-blue flowers, which are about ten centimetres across, appear on stems a metre tall. Suddenly all the effort made in making them happy is rewarded.
Everyone must be familiar with the enormous plant called ‘Pampas Grass’ (Cortaderia selloana). It is native to South America, growing on the pampas, from where it gets its name. During the 1970’s it was the ultimate plant to furnish the front garden of many a suburban house, often accompanied by a few floribunda roses and a sprinkling of heathers. Many plants still survived from this age and have often grown to be overbearing monsters.
A far more refined plant is the New Zealand equivalent, Cortaderia richardii or ‘Toetoe’ to give it its Maori name. It has a large mound of rough edged arching leaves from which emerge graceful, gently nodding, silvery-white flower panicles. They are far skinnier than ‘Pampas Grass’ and grow three metres tall when established. ‘Toetoe’ is a large plant perhaps best suited to large gardens unless we revert to the 1970’s ‘right in the middle’ tradition. It is very easy to grow, wind tolerant and not fussy about soil type. When I came to work at Picton Castle twenty years ago, I brought two little seedlings with me and these have been flourishing in the Walled Garden ever since, growing in poor stony soil and with very little maintenance except for a comb with a rake in spring to remove a few of the old leaves.
Chinese or Ornamental Rhubarb
Another giant plant, the Ornamental or Chinese Rhubarb is closely related to culinary rhubarb but looks much more refined: the leaves are larger, quite deeply incised (palmately lobed) and not glossy.
There is a lovely variety known as Rheum palmatum ‘Atrosanguineum’ which has red-purple tinted leaves – a colouring that is particularly obvious in the spring when the new leaves are emerging from the over-wintered crown in a wonderfully sculptural way. Later in the year these fade to dark-green with purplish undersides. A long established plant will flower most years but this year most plants seem to be having a year off. The flower is an imposing panicle which can grow up to three metres tall but which some people cut off, preferring to have just the impressive leaves.
In Chinese herbal medicine the first written reference of the plants qualifies dates from 2700BC. The root of the plant has been used since then to suppress fevers and for its purgative effects and it is also used for intestinal and digestive problems.
Rheum palmatum likes to grow in constantly moist, but not water-logged, soil in full sun or partial shade and when flourishing is a most dramatic and architectural plant.
For those of you who prefer gardening on the wild side, I would like to introduce a climbing rose of great beauty and size. It goes by the name of Rosa multiflora (sometimes called Rosa polyantha) but also has a range of common names such as Japanese rose, Baby rose, Bramble rose and Many-flowered rose.
Originally from Japan, Korea and Northern China and with bramble-like leaves, it bears masses of the palest pink, sweetly scented flowers along the length of its tumbling branches. I should add that, as roses go, its flowering is rather fleeting – lasting only two or three weeks – however they are much loved by bees and by August there is a plentiful display of small red hips. One of its most endearing qualities is that it is thorn-less, making dealing with its boisterous growth, which can be about three metres per year, far more pleasurable.
Rosa multiflora is easy to grow, unfussy about soil type, will tolerate quite an amount of shade and is at its best when allowed to roam freely up a tree, high wall or over a large structure. It is not widely offered for sale, however it can be very easily propagated during the winter by cutting a section of stem about 30cm long and sticking this in the ground where you would like the plant to grow. By the end of the first year it should be about a metre tall and will start flowering the following year.
The Chilean Flame Tree
The ‘Chilean Flame Tree’ is perhaps the most spectacular June flowering shrub that can be grown in gardens. Throughout the month every branch is festooned with tubular, bright-orange flowers to the extent that barely a leaf is visible. Embothrium coccineum, to give it its Latin name, are evergreen shrubs which grow in temperate forests of Chile and Argentina.
‘Chilean Flame Trees’ grow quite quickly to become large upright shrubs or small trees, often with near vertical growing branches. When happy they will start putting up suckers and eventually form a thicket, however they are notoriously difficult to get established. Some gardeners are lucky and have immediate success while others have to plant many times before they achieve a happily growing plant. The key seems to be finding the right position in your garden that has moist, but definitely not wet, soil in either full sun or dappled shade. The best plants you see tend to be growing on slight slopes which will greatly help with drainage. If you fancy a challenge this may well be the plant for you.
Palm trees evoke exotic places and look totally alien to our native flora and our normal range of garden plants with their straight single stems clad by the brown fibrous remains of their leaf bases, giving them a fluffy appearance. After about thirty years of growth these bases rot away to leave a smooth narrow stem at the top of which is a large symmetrical head of large palmate leaves up to 1.5 metres long.
Overall they have a luxuriant, slightly spiky appearance which will bring a touch of the exotic to your garden. An imposing and dramatic plant, Trachycarpus fortunei is known as ‘Chusan Palm’ or ‘Chinese Windmill Palm’. ‘Chusan Palms’ are either male or female and, this year in particular, they seem to be producing masses of extraordinary yellow flower spikes which are more strange than beautiful. Towards the end of autumn a great many seeds should form on female plants and these are quite easy to grow but are slow for the first five years until they really get going – after which they will grow about 20cm a year for about the next hundred years!
Originally from Central China, ‘Chusan Palms’ are the only reliably winter hardy palm that we can raise in our gardens and as they only ever grow upwards and not
outwards they are easy to accommodate. Bring a bit of the holiday atmosphere into your garden and try one of these palm trees – they will grow happily in light shade or full sun, however in really windy places, whilst they will be fine, they will always look tattered and unattractive.
FLAMING JUNE IN THE GARDENS OF PICTON
A month ago the Rhododendrons treated us to a riotous festival of colour. In early June, the late Rhododendrons scatter flashes of colour as they flare up in the woodlands and, the Walled Garden comes into prominence with its summer borders. There are roses old and new, aliums big and small, herbs that promise to alleviate every ailment, and the remainders of a great display of gorgeous aquilegia and poppies and interesting shoots in the borders show there’s much more to come.
To the right of the entrance of the Walled Garden, nestling in a neat scree, is a collection of succulents, many from the Canary Islands. For this southern African author, this is a reminder of home. Colours like the soft pink shades of aeoniums and the brilliant Mesembryanthemum ‘Livingstone Daisy’ emerge from the hard grey surround as they do in dry and dusty gardens all over central & southern Africa however they are not hardy and need to be over-wintered under cover.
There’s so much going on in the gardens at this time of year: stunning climbing roses add colour and texture to the walls on the south facing side: the saying that ‘the old ones are the best ones’ could refer as much to roses as jokes. The red Rosa Moyseia, the Purpureus cystis and heavily fragrant Rosa Fantin Latour are utterly heavenly. There’s an eclectic mix of colours in the herbaceous borders too. Here, the purple of Centaurea hypoleuca ‘John Coutts’ contrasts vibrantly with a red rose rambling up the south facing wall.
Within the middle borders is a pretty clustering of yellow, thistle-like Cephalaria macrophale with aquilegia behind and the stunning fat heads of these Allium cristophii add silvery purple accents at ground level, often below creamy clusters of roses climbing over arches.
In the Avenues, outside the walled garden, a lovely Cornus Kousa demands tactile attention. Papery looking leaves and an old parchment colour make the flowers look completely fake – you have to touch them to be assured they are real.
Should you pop into the toilets on your way out, then stroll back past a planting of three roses (Rosa multi flora, Leo’s Eye and Pauls Hymalean Musk) on the path that leads back to the car park.
HERE ARE THE TOP TEN THINGS TO LOOK OUT FOR THIS MONTH
Long hours of daylight and warmth mean rampant growth so it’s hard to keep up with everything that’s coming up, but the summer themes are well and truly established by late June.
Number 10: Woodland Perennials in Peep-In. Stroll up the front drive and turn right by the fallen tree trunks onto a path rich in woodland perennials. A riot of texture, colour and form, they’re the result of a nursery clear-out in the spring when excess stock was randomly planted and left to fend for themselves!
Number 9: Ferns, in the tree fern glade in Peep-In, along the approach to Peach House Wood and in the Walled Garden’s indoor Fernery. There’s more than 60 varieties of fern along the path leading to Peach House Wood alone. The lush, cool woodland provides a perfect refuge from bright summer sunlight.
Number 8: Gunneras threading through the woodlands, featuring large by the car park, re-appearing in the Avenues and going mad in the deep gulley in Peach House Wood.
Number 7: The Maze, on the way to the Jungle Garden. Don’t pop into the maze to admire the variety of traditional British hedging while in a hurry. It is very pretty and the birdsong is stupendous in the trees overhead, but escape is quite difficult!
Number 6: The Jungle Garden, on the way to the Walled Garden. The banana trees are unfurling huge leaves; daisies dance alongside gingers and cannas. This part of the garden will surely be Number 1 in a matter of weeks!
Number 5: Acers and Azaleas, in Peep-In and in the Avenues. The flamboyant colours of spring are now but a memory, but there are still great splashes of colour in the woodlands thanks to vibrant and strident azaleas in Peep-In and the Avenues.
Number 4: Echium in the Walled Garden. On the lower half of the path between the north wall and the herb border (which will soon be in the Top Ten), you’ll be confronted by towering spikes of Echium covered with tiny blue florets. Do look down too and see the huge variety of plants massed in the border .
Number 3: Roses in the Walled Garden. Duck under the Echium and continue down to the bottom wall, where you’ll find our own, salmon-coloured Leo’s Eye climbing rose. Now stroll down to the raised patio and look down to the entrance, through rose-strewn arches.
Number 2: Water Lilies in the fish pond in the Walled Garden. In the middle of the Walled Garden is a classic fish pond and fountain, with a lovely display of pink and white water lilies.
Number 1: Perennials in the Walled Garden. Take your time to admire the huge and eclectic mix of perennials coming up in the deep borders.