Tuesday, 30 November 2010

Garden Trees


I think I first became aware of the beauty and majesty of mature trees when I worked at Camperdown Park during my gardening apprentice days. There was a wide range of  broad leaved trees all now mature and a great mix of huge conifers, (Wellingtonias and Cedars) around the park, the big house and in the pinetum, which runs alongside the golf course first tee. There was a great pride by gardeners, groundsmen and foresters in their heritage and we younger apprentices were always being challenged to, “Name that tree” to see if we were learning anything. We would be in deep trouble if we did not know about our own Dundee weeping elm, the Ulmus glabra camperdownii and know the exact spot of the original tree now protected with a wee bit fence.
Dundee has a fantastic collection of trees of every kind inherited from the days of the Jute Barons, Scottish plant explorers, wealthy private estates and especially Camperdown Park awarded to Admiral Adam Duncan for defeating the Dutch Navy in 1797. The estate forester at the time, David Taylor found the Camperdown elm growing wild and now it is planted all over the world.
There are beautiful examples of mature specimens of oak, lime, beech, walnut, sweet chestnut, cedars, Douglas fir and even the more exotic Monkey Puzzle, Incense cedar and eucalyptus found all over Dundee, as well as those unusual forms of weeping ash, weeping oaks and upright oaks and hornbeam.
As much as I loved all of these trees, I was never going to have enough room in my small garden for even one of them, so my arboricultural plantings needed to be of a more modest nature.

Small Garden Trees

My first garden could only take a very small tree so I wanted one that would flower. At this time there was an avenue in Camperdown Park known as the Laburnum Walk which was very impressive in spring. So that was my choice, a Laburnum.
Everything was fine for a couple of years till the main stem got girdled with canker. I was about to lose my first tree, but a journeyman gardener suggested I remove some of the healthy branches and use them to perform a bridge graft over the cankered area. My first lesson in grafting worked a treat and saved my tree. I was now ready for another small tree.
I just love cherry blossom and if you can get one that is scented what more can you want. Prunus Amanogawa has these attributes and grows upright so is easily accommodated in most gardens. Gaining confidence I had an urge to go evergreen.
The huge Camperdown conifers were very stately but I just did not have room for a cedar, monkey puzzle or Wellingtonia, but I could manage a small upright golden yew, Taxus baccata fastigiata aurea. Later on I would acquire a whole range of conifers all of modest proportions suited to both small and medium sized gardens.
My favourites at this moment are Thuja occidentalis Rheingold and the dwarf form of Weymouth pine, Pinus strobus nana, and every garden can find room for at least one dwarf Pinus mugo.

Planting trees is for the long term so it is very advisable to do some research with gardening books in your library, or at a local garden centre or for the more modern gardener with a computer go onto Google. You will soon come across those trees you really like and of a size to suit your own garden.
In the past too many people just went for the cheapest available and ended up with a Leyland cypress and globally creating such a nuisance that laws needed to be introduced to tackle the problem.

Many of my garden trees started off as dot plants in a flower bed designed to add height and contrast to the flat, but bold colour display of Begonias and geraniums. Eucalyptus,  Cordylines and the date palm, Phoenix canariensis are perfect in summer flower beds, but in autumn when the summer flowers are past what do you do with these dot plants.
I always find a home for them somewhere, but remember with global warming they may survive our milder winters and put on a fair bit of growth.
Every ten to twenty years we get a bad winter, like last year, which really tests the hardiness of garden plants. My eucalyptus tree, now over 50 foot tall, got quite a fright and shed a few leaves, but it has survived. The young Cordyline just a ten foot baby survived unscathed, but my exotic date palm got cut down to ground level. It is still alive, just, so time will tell if the crown will yet again grow into another brilliant specimen. Never be too quick to give up on plants that have been frosted. Often they can grow again from the base.
If there is room in the small garden find space for a lilac which will be covered in white or lilac scented flowers in early summer. They do not grow too big.

It is sometimes difficult to distinguish a small tree from a large bush. Cotoneaster frigidus grows the same height as the lilac, but is more of a tall shrub. Then another very tall shrub or small tree is the Eucryphia Rostrevor. There is an absolute beauty in Camperdown Park near the pinetum covered in white flowers in late summer. It has a broadly columnar habit and can reach 30 feet or so depending on soil, shelter and climate.

Specimen trees

Sometimes the small garden can get a boost with a particularly good form of tree planted centrally in a lawn or other conspicuous spot.
The small garden can use the graceful silver grey willow leaved pear, Pyrus salicifolia pendula, or if there is more space the dazzling white stemmed birch, Betula jacquemontii. Then for a bright golden splash of colour all summer plant a Robinia frisia, but remember it needs good drainage.
Another good specimen tree is the weeping birch, Betula pendula youngii. It is very graceful and quite small but extra height can be encouraged in its young growing stages. Buy a young specimen and train the main growing stem up a very tall cane for a few years. I got mine over twelve feet before I let it grow as a weeping tree.
An excellent flowering specimen tree with an architectural shape is the Japanese Mount Fuji cherry, Prunus Shirotae. It is outstanding in full blossom.
Some tree species have columnar growing forms that do not take up too much space, at least in the early years. The upright Cypress oak, Quercus robur fastigiata , (several along Riverside Drive), is very majestic and quite similar to the upright form of hornbeam, Carpinus betulus fastigiata.

It is the larger gardens that have the space to indulge in the finest tree specimens from the modest Liquidambers to the weeping silver lime, Tilia petiolaris. Now that will make a statement, but then, so will a perfect specimen of the blue Atlas cedar, Cedrus atlantica glauca allowed to retain its branches down to ground level.

Apologies for all the inclusion of the boring bits, (botanical names), but if you want to make sure you get the correct plant you will need its proper botanical name. Plants usually only have one botanical name but numerous common names that differ depending on where you live.

Tree Care

It is very important that you are aware of just how big your tree will grow to on maturity so you can plant it with due regard to any future problem.
If trees are planted for shelter or screening around boundaries keep them well away from your neighbours property, and make sure they cannot block street lighting columns, road signs, and site lines at road junctions.
There is healthy debate on how close trees should be planted to property and different bodies give different views. Some say the distance should be from one to one and a half times the trees ultimate height from the base of the property. However trees all vary, and some are very little problem, whereas others such as willow and poplar should be kept at least twice the ultimate tree height and not near any known land drains as they have strong root systems that will seek out any available water.
Trees planted too close to buildings can be a big problem in dry spells as they will extract moisture from an already dry soil. On a shrinkable clay this can cause the ground to heave once the rains return. If any foundations are not up to scratch building walls can crack.
Now you know the pitfalls you can select your specimens with more confidence.


Wednesday, 24 November 2010

Garden Climbers


I first became aware of the possibilities of climbing plants at the beginning of my gardening career when my small council house garden was just not big enough to grow all these plants I was learning about. By utilising all walls and fences I could extend the range.
It soon became clear that there were plants that would enjoy a north facing wall, whereas the more exotic climbers would thrive on a south facing wall.
A new world emerged for the young very keen apprentice gardener who lost no time in covering every available wall and fence space. The house soon blended into the landscape.
Fences erected along property boundaries, or separating garden areas, or creating privacy and shelter around patios would all be enhanced with scented flowers and autumn berries.
Being a fruit lover these walls and fences would provide the correct conditions to grow many fruit trees and bushes where space was at a premium.
As life moves on the garden is now a lot bigger, but so is my knowledge of plants that I want to grow or experiment with. So I am back to the original problem of not having enough room. I need to be quite selective on what plants I choose to grow..

Special needs

My first success was finding plants that would grow on a north facing wall where good sunshine was a problem. To convert a dull dark north wall to one with flowers was a great achievement. Climbing rose Mme Alfred Carrier, or Ena Harkness and  Jasmine are all  good.
Then what about the east wall where early sun would affect any late spring flowers if there was a late frost. Choose something that flowers in summer.
I placed a great value on walls next to main front doors. These needed scented flowers to enhance the feel good factor for anyone going into the house.  Climbing rose Zephirine Drouhin and Gertrude Jekyll are both perfect pinks for this spot.
Property security can be improved by planting Pyracantha around any vulnerable windows. They can also thrive on north facing walls and although very vigorous, they adapt very well to spur pruning to keep them close to the wall while retaining their thorny framework and bright autumn berries. Blackbirds just love to nest in them.
Walls and fences are becoming very popular places to plant fruit trees and bushes on as people now want an apple, pear, cherry or peach but normally they would grow quite large, so nurseries now cater for this use. Espalier trained trees, smaller growing stepover trees, and dwarf cherries are all now available. Now cherries grown on the new Gisela 5 rootstock will only grow to six to eight feet tall, so can easily be netted against birds so you get the fruit and not the birds.


Some plants support themselves and climb using their twining tendrils e.g. vines. Others will twine around any support, e.g. honeysuckle and clematis, some attach themselves with adventitious roots appearing in the shoots, e.g. ivies, but many others require an artificial support to be trained against. Most climbing roses will need support as will Pyracantha, and fruit trees. Wooden fences may give support by way of their construction, but can be enhanced with strong wires stapled firmly along its length. Trellis is very useful as well as six inch weldmesh. Walls can be drilled and vine eyes inserted to hold strong horizontal wires for training. Every situation will be different and each plant will have its own particular needs.
An overgrown leyland cypress hedge can be cut back to ten feet or so and most of the branches removed, just retaining enough to keep them alive and give support to a few climbers. Allow some regrowth, but not too much to create a nuisance. Clematis will thrive here and some climbing roses can be added. In time the clematis will hold onto the climbing rose  and keep it upright.


Very often there will be a perfect house wall space but totally paved with no soil near it. Most plants only need enough soil to get them started. I have frequently removed a two by two slab against the house wall then excavate ten inches of builders rubble before loosing up a further six inches. Backfill with some decent top soil adding a bit of compost and some fertiliser to the pit. Keep any new plant well watered till it gets established. It will soon find spaces to grow in the builders rubble and be perfectly happy. My climbing rose Dublin Bay will reach seven feet in height according to the catalogue. However once the roots found the rubble it just grew and grew and now I have had to severely prune it to keep in down to twelve feet.


Climbing plants can add interest all year round by using the benefits of each different wall. South facing walls catch the most sunshine so will bring plants on earlier and retain colour longer at the end of the season while north facing walls extend the plant range to those that would otherwise suffer too much sun.
North facing walls are perfect for the yellow winter flowering Jasminum nudiflorum which starts to flower at the beginning of winter and continues for a few months. Camelias on a north wall can follow on into the early spring, and being a woodland fringe plant they do not mind shade as long as they get some sun in summer to ripen up the wood to allow flower buds to develop.
Clematis in its numerous varieties and hybrids will give a display from spring till late summer. Clematis montana rubens may be very common, but it is one of the best for a mass display of pink flowers. It is very reliable, quite vigorous and loves to scramble into old trees, over sheds, tall fences, conifers, etc.
Where scent and flowers are both important go for a honeysuckle. That will take you into summer. Now there are numerous climbers and ramblers to choose from. Roses are very adaptable, but choose a variety that has disease free foliage able to resist black spot, mildew and rust. Chemicals available at garden centres have to be very safe for public use so are usually quite dilute and do not always work effectively unless you spray at fortnightly intervals and each spray does not get washed off with rain soon after application.
My favourite autumn climber for any wall is the Firethorn, Pyracantha Orange Glow, though there are several yellow and orange berried forms.

Fruit bushes

Redcurrants and gooseberries can be trained as cordons on an east or west wall, but keep your south facing walls and fences for those fruit that can benefit from more sunshine.
Apples and pears trained as fans or espaliers thrive on a south wall, but so also do figs, cherries, peaches and the vine Vitis vinifera Brant. The vine needs support for its tendrils to hold onto. It has small but very edible fruit and brilliant autumn colour.
All of the fruit trained against walls require pruning specific to their individual needs to control growth, expose fruit to the sun and ripen up shoots to fruit the following year.


Wednesday, 17 November 2010

Ornamental Berries


Beauty in the garden presents itself in numerous ways throughout the year. The impact of bold bright summer flowers is replaced in autumn with brilliant leaf colours as well as berries, fruit and hips. Most plants reproduce and spread by means of seed dispersal and have all developed amazing methods to ensure their success amongst the competition.

Plants need to ensure that their seed is spread well away from the parent plant so some have developed wings e.g. sycamores and maples, some have hooks such as sticky willie, and some open with an explosive power to shoot seeds good distances, e.g. brooms and gorse.
Chestnuts and oaks provide a food source for squirrels who collect the seed and dig holes in the ground to store them for the winter. There is always a good chance that some will survive the ravages from the hungry squirrel and grow into a tree.
The ornamental fruiting trees and shrubs started of as edible fruit for wildlife who travel away from the source eating the fruit on the journey and disperse fertilised seed in their droppings. Humans have played a role in dispersal of apple trees grown from seed along railway embankments as the apple cores were thrown out of the windows from older steam engine trains.
People have grown plants for eating for generations and realise that there is also a visual pleasure in seeing a tree or shrub in full crop with brightly coloured fruits.
Nurseries and plant breeders have taken this a stage further in developing new improved varieties and selecting the best clones to extend the available range of ornamental trees and shrubs with impressive displays of fruit.


When I was selecting suitable apple trees for my garden in Dundee I decided that they would need to be bright red as well as having excellent eating and storing qualities. Discovery is my early, Red Devil my main season and Fiesta and Red Falstaff my lates for storing, but while on the tree they all provide a fantastic display of bold colour.
Katy and Scrumptious are also very good.
However if a good display is more important than cropping potential try some of the ornamental crab apples such as Malus John Downie or Golden Hornet. After a while if you are tempted to use the fruit they will make an excellent jelly.
For those who are more patriotically Scottish a rowan tree will be high on the list. In past times they were necessary to ward off evil spirits, but old traditions die out and now they are grown in numerous forms for a very wide range of ornamental berries and autumn colour.
The common species, Sorbus aucuparia is grown all over Scotland and has eye catching scarlet foliage in autumn with a huge crop of scarlet berries which dont last too long as the birds just love them. The variety Sheerwater Seedling has been bred for its upright growth making a perfect tree avenue which does not interfere with traffic movement.
The yellow, pink and white berried rowans give a longer display as birds are not in a hurry to devour them like the red fruited types.
Joseph Rock has yellow berries amongst scarlet foliage, Sorbus cashmiriana has white berries and both Sorbus hupehensis and vilmorinii fruits start pink then slowly change to white tinged pink.
The genus Sorbus also includes the whitebeams which have broader grey leaves and scarlet berries which can last a long time. They make very impressive bold trees. The best ones are Sorbus aria lutescens and majestica where the grey summer foliage turns golden in autumn.

Berried Shrubs

Holly grows to a small tree size and is evergreen and will fruit in most years. It is very popular for a festive decoration around the home, is very easy to grow, but is not too fast.
Coming down the scale in size the Cotoneaster genus grows from a small tree such as C. frigidus to ground cover such as C. dammeri. They all get covered in bright red berries that last well into winter. The species C. horizontalis has a herring bone pattern that really excels when frosted. It is very useful for ground cover as is the variety Autumn Fire though it can be quite rampant. Cotoneaster simonsii is a very useful medium sized shrub for screening, but its prolific red berries get eaten and carried by birds all over the garden. It would seem that almost every seed wants to germinate and grow. This can be a problem.
Berries come in all colours from the white snowberry, Symphoricarpos albus, the violet purple Callicarpa bodinieri, the deep blue black Mahonia aquifolium to the bright orange sea buckthorn, Hippophae rhamnoides.
Sea buckthorn fruits are displayed on a silver grey feathery foliage that is great in maritime places as it tolerates sea spray and dry sandy soil conditions. It is a popular plant for vandal prone areas too, as it has a lot of thorns, and its strong root system and ability to sucker makes it useful to stabilise steep slopes and river banks. Breeders have been busy growing plants that can be easily harvested as the edible berries are very healthy once processed into juices and jams and essential oils are extracted from the seeds. It is also used in cosmetics and even in baby foods. The edible berries are very high in vitamin c,  but may have to be cooked in some recipe to get the best flavour from them.
Another excellent evergreen ground cover plant smothered in red, pink, lilac and white berries is the Pernettya. The berries last all winter until they get sweetened up for consumption by birds in late spring when there is precious little else for them to eat
The plants are female so you will need a male pollinator to ensure a good crop of large berries. You may have to order a male plant as they do not have sales potential in nurseries if there are no berries on them. Some species of male Pernettyas do however produce some berries as they may have a slight androgynous tendency.
It doesn't just happen to humans.
There is quite a bit of controversy as to whether the fruit is edible. For some native south American Indians Pernettya fruit was a major food source in summer and winter and different species were reported to have hallucinogenic chemicals or could make you intoxicated. The North Carolina State University studies reported the whole genus highly toxic and warned they may be fatal if eaten.
My local blackbird seems happy to gulp them down every late spring and always flies of in a straight line. He probably hasn't read the report.
Skimmia has always been popular as an evergreen low growing shrub with red berries. It is also dioecious so you need a male pollinator for the berrying female plants.


It is the common practise to remove the seed heads after flowering to conserve the plants energy for flower production, but some rose types have very attractive large bright red hips.
Do not remove these hips as they will be the attraction well into winter. There are many varieties, but they mostly come from the two species, Rosa, rugosa and Rosa moysii.


The Firethorn, Pyracantha comes in many varieties with red, orange and yellow berries. These are produced quite prolifically on tall thorny evergreen bushes which are usually treated by pruning to grow as a wall climber. Birds love the fruit, so although the display is short lived it is quite stunning for a few weeks.
The outdoor ornamental grape vine, Vitis vinifera Brant produces numerous small bunches of black sweet grapes. It is quite vigorous but is easily kept under control with pruning. It is best trained along wires on a south wall. Autumn colour of the large vine leaves is brilliant.


Sunday, 14 November 2010

Autumn Colour


A gardeners world has always entailed a fair bit of energetic graft, but then later you reap the reward. It may be the tasty fresh produce you have grown or the beautiful plants now looking their best, or a tranquil spot in which to relax in a sunny corner. If only you could ignore that never ending voice in your sub-conscious reminding you of that weed that needs removing, the broken fence to repair, a few plants needing potted or some other job from a long line of tasks that never end. However, summer is gone, the sun lounger is in store, so  topping up the sun tan is no longer an option and a new set of tasks for autumn is reaching priority status.
However, autumn does come in a brilliant blaze of colour that can take your breath away.
When the garden is being planned and planted up in the early years, this is the time to consider good plants for autumn colour as the best are usually trees or shrubs that need careful thought to allow them space to grow. Your garden size will determine what you can select.
I usually start by looking at the space for a tree or two. They come in all sizes so it is not difficult to find an appropriate list suited for shelter, screening, blocking unpleasant eyesores, or specimens to be admired. In UK most trees, other than conifers are deciduous so there is plenty scope for colour when they lose their leaves in autumn.

Brilliant trees

If you are blessed with a large garden you can indulge in any amount of forest trees with excellent autumn colour from the scarlet red oaks, bronze beech, golden maples and sycamores, horse and sweet chestnuts, lime, poplar, and even some elm if you are happy to risk the ravages of any remaining Dutch elm disease. They will all give a brilliant display in the autumn, but do some research before you buy as there is always some outstanding varieties within any one type.
It is always hard to pick a favourite but Acer cappadocicum rubrum is hard to beat if you can find one.
There are a few deciduous conifers that put on a dazzling display in autumn. Larch is the most frequently used, but try to find space for the Dawn Redwood, Metasequoia glyptostroboides, the swamp cypress, Taxodium distichum,  or the maidenhair tree, Ginkgo biloba. These are all large trees ultimately though some are slow growing and worthy of a place for ten years or so before they get too big.

Smaller gardens can still enjoy a wide range of good autumn colour with other species such as rowans, whitebeams, cherries, upright forms of hornbeam, liquidamber, amelanchier, maples and  birch. There are very many different forms, sizes and attributes for all of these trees, so as tree planting is for the long term do some research before making your purchase.

Dazzling shrubs

There are just as many types of shrubs as trees coming in all sizes from ground cover to small trees. They are used to form boundaries, hedges, and as ground cover to smother weeds. Some give shelter and privacy and are often mixed into shelterbelts, windbreaks and woodland fringes to add variety, interest and colour. Some types can be used on steep banks to prevent soil erosion with added benefit of providing food and shelter for wildlife.
Shrubs are often grown for their flowers or other features and good colour in autumn is a bonus. Deciduous azaleas have brilliant autumn colour as well as dazzling scented flowers in spring. Contrast them with the smoke bush, Cotinus coggygria which turns a deep scarlet.
However the plant with the widest range of brilliant colours must belong to some of the Japanese maples. I grow several of these, but Acer palmatum Sangokaku is not only fantastic in autumn but also has bright red stems that glow in the sun all winter.
Autumn is also a time when the heather garden attains bright scarlets and golds on many of the Callunas.
Then don't forget the fruit garden as the blueberries brighten up at leaf fall as well as the saskatoons and chokeberry, Aronia melanocarpa. The latter is fast becoming popular as demand for quality superfood increases. The Aronia may only be known as an ornamental large shrub with almost edible berries and excellent autumn colour at present, but its fruit quality is at the highest level for anti oxidants.
My two best climbing plants for autumn colour are the  Virginian creeper, Parthenocissus and the ornamental grape vine Vitis vinifera Brant. Careful with the former as it can be very vigorous and grow very tall, and Vitis Brant is also vigorous, but easy to keep in check with pruning. It will need a support to cling to with its tendrils. Its leaves turn scarlet and gold in autumn and its fruit bunches may be small but they are delicious eaten fresh or as a juice extracted from the fruit and kept in the fridge for up to two weeks. Surplus juice can be frozen.
Now we have enjoyed some blissful moments amidst the colourful gently falling leaves our thoughts go back to the next job needing attention

Autumn tasks

Those once admired leaves have now dropped down and will need raking up, and then this is the last chance to remove weeds before winter begins. I always like to go into the winter with weed free soil. A lesson from history. Hand weeding frosted flower beds in Dawson Park in winter 1960 was not an awful lot of fun. A passing lady walking her dog in the park was overheard telling her friend, “the patients do a marvellous job “
This is also a good time to spread a mulch of rotted compost on those borders planted with bulbs. Once the bulbs begin to emerge it is too late to put any compost on without doing some damage.
Garden tables and chairs can now be brought inside to protect them from winter weather, as opportunity for an outdoor coffee break is only reserved for the hardiest of patients.

Renovate lawns

Lawns may be purely functional as a place for the dog and kids to play on, or it may be a surface of excellence maintained to the highest level. The mower usually determines the standard, ie. use a rotary for the normal suburban lawn, but a cylinder with grass box for the perfect lawn with stripes. To keep the high standard of surface, autumn renovation work is an essential routine. Any broad leaved weeds will have been removed during the growing season, but moss can be a problem in autumn. Spreading lawn sand is the normal practise, but it may contain a fast acting nitrogenous fertiliser, so I prefer to use its active ingredient sulphate of iron alone. This needs careful diluting in a watering can, then test a small patch before you water the whole lawn. It can be very strong so care is needed, but it is very effective. I also use it on any mossy path areas. The moss turns black in two days.
Scarifying the surface with a springbok rake will also remove moss and any build up of thatch.
To improve surface drainage use the garden fork to put small holes about two to three inches deep into the surface at about six to nine inch spacings. Then spread on an autumn lawn compost dressing which will have an organic slow acting fertiliser in it  This should have a higher ratio of potassium and phosphates and be low in nitrogen. Brush the compost into the holes.