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.


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