Browsed by
Category: About Trees

Articles involving trees, shrubs, bushes, woods and hedges plus related subjects

Rose Year 2018

Rose Year 2018

In the UK it has been a fantastic year for flowers, no more so than an English favourite the Rose.

Parks and gardens have been over flowing with stunning blooms and scents.

2018 may be the start of a rose resurgence and I will be tempted to buy a few more bare rooted rose trees this backend.

Have I just been fortunate or has the weather restricted pests and diseases? No rust, negligible blackspot and only one plant suffering from mildew.

It may be too soon to say farewell to greenfly but I live in hope for the second flush from the HT roses.

After generally a good year for fruit and berries I wonder what to expect from rose hips this autumn. My Rambling Rector put on a good show and now I hope for a surfiet of hips. Rugosa roses needed more moisture and were one of the few poor performance in 2018.

Trees Near Buildings

Trees Near Buildings

The UK is experiencing a significant drought following a very wet spring. Trees were encouraged to put on extra foliage and they are now regretting the extra moisture they need to transpire. This is leading to more cracks in the surface soil and could lead to permanent damage.

Trees take up large volumes of water during summer. Shrinking and swelling of clay soils can be a concern but trees 30 feet from buildings should not be a major concern. However it is wise to avoid large vigorous and thirsty trees like Oak, Poplar and Willow.

Root Damage

  • Main roots are usually confined to the top 3 feet of soil
  • Shrubs and climbers are seldom implicated in root damage.
  • Swelling trunks close to buildings may squeeze against structures.
  • Root size and extent is variable dependant on species.They seldom penetrate well maintained drains but vulnerable drains should be repaired.
  • Roots radiate irregularly seeking moisture and nutrient. They may spread two to three times the height of the tree.

Subsidence & Structural Damage

  • Older buildings with shallow foundations are more vulnerable.
  • Soils other than shrinkable clay do not swell and contract as much as other soil and seldom cause damage.
  • The side of a building nearest the tree can settle due to its weight in dry soil causing cracked masonry, distorted doors and windows.
  • Fences, hedges and boundary walls may be damaged by proximity.
  • Paths can be lifted by robust roots.
  • Wind damage to trees may make them structurally unsafe.

General Tree Issues

  • A tree is the responsibility of the landowner who may be liable for any damage it causes.
  • Check with the local planning authority to establish if a tree has a ‘Tree Preservation Order’. They should also know if the garden is in a designated conservation order whose objective is to conserve landscape and public spaces in an area.
  • Trees have atendency to grow larger than you originally intended. They can block out light through your windows, shade gardens and over hang into your neighbors garden.
  • If you need to remove a large tree be aware that the large volume of water it previously transpired will remain in the ground and may lift the water table, swell the soil and cause ‘heave’ or displacement.
  • Gutters and roofs may suffer from leaf litter.
  • Surface roots and suckers can be invasive.

Further Tree Safety Tips

  • Think about the future life and nature of your tree before planting or starting work. It pays to plan ahead.
  • If a large tree needs pruning, lopping or taking down use a tree surgeon who has full insurance.
  • Consider neighbors and  overhangs across roads and public paths.

 

Dendrology for Gardeners

Dendrology for Gardeners

Dendrology is the the branch of botany and science about trees and other plants that have woody structures. It includes the natural history of trees, species identification, taxonomic classifications and economic significance.

Natural landscapes, forestry, arboreta, horticultural businesses and our gardens are locations that benefit from dendrological study. In the UK there are many parks and urban streets containing trees but the number seems to be diminishing. It is therefore up to gardeners to maintain an interest in growing and caring for trees and woody plants.

Book Cover

A new book to be published in 2019 ‘Dendrology: Cones, Flowers, Fruits and Seeds of Europe’ will provide a comprehensive overview of the morphology of reproductive organs of European woody plants in one resource. Over 355 species of trees and shrubs are to be described including species that originate from North America, Asia, South America, Australia and Africa. At a price of £200 this is not for your average gardener. Better to stick to your own note book costing less than a fiver (above from amazon).

Associated Facts

  • An arboretum is a botanical garden containing living collections of woody plants and is intended at least in part for scientific study. On the other hand a Xylarium is a herbarium containing a collection of wood specimens.
  • The aims of the International Dendrology Society are to promote the study and enjoyment of trees and other woody plants and to protect and conserve rare and endangered plant species worldwide.
  • Silviculture is the  science of controlling forests and woodlands and of forestry management.
  • Dendrochronology is the art and science of tree-rings. Dendroclimatology uses tree-rings and wood density to analyse the that climate was likely to have caused the rings.
Tree Peonies from the Far East

Tree Peonies from the Far East

tree peony

History of Tree Peonies

The ancient Chinese have cultivated Tree Peonies for over 1500 years. Prized specimens are and were grown for medicinal purposes as they contain glucocides and alkolides. The  imperial palace gardens had many specimens that became quite valuable.

The tree peony was, for a time, the national flower of China and it is thought Chairman Mao sought to ban their growth as a decadent pastime. The root of P suffruicosa has been used in medicine for centuries.

Plants were transported to Japan in the 14th century. The Japanese  bred tree peonies creating over 1200 hybrids some of which are still grown today.

The cult status of Japanese Tree peonies encouraged 18th century plant hunters to import tree peonies in to Europe, particularly France and England. These plant hunters like Veitch, Joseph Rock and Kelway started their own breeding programmes from some of the five wild species and other hybrids.

 

 

The Americans crossed P.lutea (above) and P. delavayi with Japanese hybrids to produce some of the vibrant colours now available. The flowers have a short but colourful life! The shrubs are far more long lived.

Tree peonies have long featured in oriental watercolour paintings. by Zou Yigui (1686–1772). Some of the varieties, like ‘Yao’s Yellow’ and ‘Wei’s Purple’ are  depicted in a series of paintings  mentioned in the Record of the Tree Peonies of Luoyang  Ouyang xiu (1007-1072 CE).

 


Imagine the splendid sight when all the buds open.

 

 

Bamboo Care and Maintenance

Bamboo Care and Maintenance

Lawns are cut regularly to encourage side shoots, prevent flowers and to keep the grass tidy. Some attention should also be given to other grasses and bamboos to encourage production of fresher growth at the beginning of the growing season.

bamboo ice

Pruning Bamboo

  • All bamboos look better when scruffy, broken or damaged shoots are removed.
  • Thin out dense thickets to create space for the flexing stems of new shoots.
  • Cut out old canes with sharp loppers or a pruning saw flush to the ground.
  • Thin out other shoots to create a balanced, airy clump.
  • Prune above a node to prevent die back.
  • Weak side shoots and branches often look unattractive and a judicious pruning improves appearance.

Bamboo Care

  • The best time to thin and prune is late spring just before new culms emerge.
  • Don’t be afraid to remove 30% of the culms leaving the freshest one-two year olds.
  • For more growth from dwarf bamboos cut down to soil level in early spring and treat like a hardy perennial to get fresh clean foliage.
  • Instead of under planting you can decorate with stones or round pebbles.
  • Some bamboos are invasive and the tough, springy roots need to be removed or root pruned annually. Plant a barrier at least 18 inches deep around invasive types.
  • Bamboo can be turned into Topiary as the leaves grow more abundantly after pruning and the culm won’t grow
  • Bamboos need to be replaced every 10-15 years
  • Water plants in late spring during a dry spell to help new shoots to develop.

Bamboo

Bamboo in Pots

  • Potted bamboos should never be allowed to dry out even in winter.
  • Because bamboo is tall, it may be susceptible to being blown over so weight the pot accordingly.
  • Bamboos make good subjects for growing in pots. I use terracotta pots as the colour seems to go well with the green leaves.
  • Pots restrict the root run of the plants and they should be trimmed every year.
  • Arundinaria viridistriata ‘Pleioblastus’ or Phyllostachys nigra ‘Black Bambo’o are decorative dwarf bamboos suitable for pot culture.
  • Feed with a high nitrogen feed as bamboos are hungry plants and you are their only source of nourishment.

New Bamboo Boulevard at RHS Harlow Carr

New and Urban Hedge Rows

New and Urban Hedge Rows

Hedge your bets and start a hedge fund and do not hedge around!

This isn’t my favourite hedge spotted on a walk to Menston railway station but it hints at what can be achieved. I would now opt for a fruitful hedge to feed me and the birds.

  • The blending of green, grey and red foliage has produced a singular hedge.
  • Mixed colours work best if kept formal, neat and tidy
  • Do not allow one type of plant dominate another, these all seem to be in proportion but vigorous growers will need more trimming
  • Different shaped foliage could also be blended in a mixed hedge
  • The stone wall provides some relief from the base of the hedge
  • Train lower branches into gaps. remove extraneous plants like the Choysia on the left

How to Plant A Hedge

  • Plant a bare root hedge in winter between November and March.
  • Buy 2 0r 3 year old plants in bundles. If you can’t plant them at once heel them into a trench.
  • Protect plants with a plastic bag whilst they are out of the ground.
  • Clear the ground of perennial weeds and keep it clear by hoeing.
  • Dig a trench 18″ wide for a single row of plants. Loosen the soil at the bottom of the trench and add slow release fertiliser like bone meal.
  • It isn’t necessary to add organic matter except perhaps as a mulch after planting.
  • Sprinkle any fungi treatment directly onto the bare roots before planting.
  • Water the hedge for the first year but then leave it to it’s own devices.
Miniature Pines are Smaller than Dwarf Pines

Miniature Pines are Smaller than Dwarf Pines

What is a Miniature Pine

  • Small pine trees have been grown and sold as Dwarf plants for years but true miniatures are raised as clones from potentially larger species.
  • Miniatures are classified as such if they will not exceed 40cm height or width over 10 years. Experts recommend exhibition quality plants should not grow more than 25mm per annum ie. 25cm in 10 years.
  • True miniatures are clones of other pines.
  • They may  grow as spontaneous sports, as bud mutations or seed faults .
  • Witches brooms creating miniatures pines are dense growths that result from virus infection or insect damage.
  • Bonsai are restricted growth plants and not true miniatures.

Miniature Pine Varieties

  • Pinus mugo Donna’s mini 20x30cm cushion form
  • Pinus mugo Mini Mini  globose habit 20×25 cm
  • Pinus mugo Suzi 30x30cm spreading with orange-broan new growth
  • Pinus mugo Zwergkugel 35x35cm
  • Pinus mugo unicinata Jezek 20x30cm  good cushion form
  • Pinus mugo Bonsai Kramer 10x20cm
  • Pinus syvestris Marshall  30x25cm
  • Pinus syvestris beauvronensis ultimate height 24 inches growth 1.5″ per annum
  • Pinus strobus
  • Pinus uncinata
  • There are many other species that sport or produce miniatures but pines are consistent favourites.

Dwarf Species include;

  • Dwarf conifers are at least twice the size of miniatures after 10 years. As the sign above shows many conifers are sold as Dwarf plants
  • The pine family includes Dwarf White Pine, Dwarf Swiss Mountain Pine,
  • Many conifers sold as Dwarf are just slow growers and will continue to grow into sizable trees given time and favourable conditions.
  • Dwarf Lebanon Cedar, Dwarf Alberta Spruce,  Dwarf Japanese Juniper.

 Collecting and Displaying Miniature Conifers

  • Miniature conifer is the catch all name for the smallest of the conifer family.
  • The size makes them ideal for use in miniature landscape plantings, alpine or scree gardens, troughs and pots.
  • Miniatures are also popular for exhibition purposes.
  • Restricting the size of a pot can cause the needles on lower branches to fall
  • Top growth shouldn’t extend over the pot. Repot as the conifer grows until you have a pot 36cm or so. There after the miniature pine may be happier in the ground .
  • The main shape and forms of miniature pines are conical, globus, pyramidal or spreading.

Growing and Cultivating Miniature Conifers

  • Miniature conifers are never likely to outgrow their situation.
  • Pot miniatures into a compost of equal amounts of John Innes no.2, grit and composted bark.
  • The aim is a tight bun with closely displayed needles and a compact display. Fertiliser is only needed occasionally and in frugal quantities.
  • Thatch or dead needles should be removed from inner branches to avoid die-back.
  • Shallow, plastic pots are lighter to move around and should not harm the plants.
  • Prevention is better than cure so treat for vine weevil and dose annually with a fungicide.
  • Top dress annually with compost.
  • Outdoor specimens can be trimmed in spring by candling (removing new extension growth) to retain shape.
  • Plants can be grafted onto clean longer stemmed rootstock but why would you want a tall miniature.
  • Side grafting on to compatible rootstock can be done in January and then kept frost free.

Comment

Miniature conifers and especially pines are worth growing in a cold greenhouse or outdoors. There is a range of shapes and colours to cultivete and a good supply is available from Kenwith Nursery growing miniature and dwarf conifers for the last thirty five years.

Kenwith Conifer Nursery

Mahonias make me Prickly

Mahonias make me Prickly

Every winter I am on the Oregon trail for garden scent. My best hope is the Mahonia (aka Oregon grape) which grows very well in various shady parts of my garden and flowers profusely in winter. Regrettably I find the much acclaimed scent is hard to detect but smell is not the only thing that gets up my nose! The rigid leaves have several vicious points on  the arrayed leaves and catch me out many times a year. This is partly due to a 6 foot shrub near my Japanese garden path. I don’t know what made me think Mahonia was suitable in a Japanese garden but there you go. As a deterrent to uninvited visitors the prickles make it as good as Holly and a close second to Berberis.

The stems or branches are an interesting yellow colour but only get seen when pruning.  I prune or trim regularly which aims to keep older plants in shape. Other maintenance is minimal as no critters would make a meal of the leathery, spiked leaves.

Mahonia Oregan Grape

Berries that give Mahonia the Oregon Grape name

What the Experts Say

M. japonica is an erect medium-sized evergreen shrub with large, spined, leathery pinnate leaves and small, fragrant light yellow flowers in spreading or drooping sprays from late autumn to early spring, followed by blue-black berries ‘RHS’

These woodlanders will appreciate a mulch in early spring and a tidy up underneath the main stem.

Selected by the Sunday gardener from over 50 species Mahonia popular cultivars  include

  1. Mahonia x media  ‘Charity’,   ‘Winter sun’ and ‘Lionel Fortescue’  These have large upright yellow, scented flowers. ‘Charity’ can be grown in a north facing spot which makes it a good shrub for a difficult growing area.
  2. Mahonia fortunei smaller 1.2m high 1 m wide which flowers in the autumn
  3. Mahonia aquifolium  known as the Oregon Grape is very hardy   flowering in March and April followed by blue black berries.
  4.  Mahonia  x media Underway AGM a tall grower reaching up to 3m with large erect spikes of fragrant yellow flowers in the winter.
  5. Mahonia japonica a mid sized shrub growing up to 2m.
  6. One to look out for is a new red flowering Mahonia called Mahonia nitens ‘Cabaret’ .
  7. Gardeners Tips    Berry Bearing Bushes for Birds
  8. G Tips  Mahonia  Attractive Spiky shrubs

Uses for Mahonia Oregon Grape

  • The small purplish-black fruits, which are quite tart and contain large seeds can be eaten in small quantities.
  • The fruit are sometimes used to make jelly or mixed with berries from Gaultheria.
  • Oregon-grape juice can be fermented to make wine
  • The inner bark and larger stems and roots of Oregon-grape yields a yellow dye.
  • The berries can produce a purple dye.
  • The foliage is sometimes used by florists for greenery which functions like holly as the leaves remain rigid.
  • If consumed in large quantities berries can cause vomiting, lowered blood pressure, lethargy, and other ill effects. Consumption is not recommended but tinctures and essences are available on the internet.
Lifting Your Tree & Shrubs Crown

Lifting Your Tree & Shrubs Crown

Giving trees what I call the ‘Royal Chop’ is not as drastic as it sounds. It is one way of controlling the low growing branches that restrict light, create unwanted shade  and generally get in the way. The technical term may be to ‘Lift the Crown’ which has the result of leaving the lower trunk clear of branches and letting the growth starting at an acceptable height.

My problems  started when I couldn’t reach the upper part of the conifer to keep it in trim. The same energy is going into the trees growth without an outlet at the lower end so it gets a bit wider and a lot taller. I pruned out the lower branches leaving about one third of the trunk height bare.

Had I taken out the growing point at the top of the tree the spread of lower branches would have been far wider and been the opposite of what I wanted. Conifers trimmed in spring were not the best subject to learn, on broad-leafed trees trimmed in autumn or winter may have worked better.

What the Experts Say

‘Crown lifting is the removal of the lowest branches to a specified height and where possible should be achieved by removal of smaller branches so to minimise stress to the tree. The crown of the tree should not be lifted to a point which is more than 1/3 of the overall tree height (i.e. leaving 2/3 of the trees height as crown).’ Crown thinning and crown reduction are variations that are also  designed to change the extent of the canopy.  Nick Organ Tree maintenance

‘Crown lifting on older, mature trees should be restricted to secondary branches to minimise stress and reduce recovery time. It is possible to crown lift a tree too much. Chaffin Tree Surgery

Shrubs Suitable for Crown Lifting
Acer palmatum and Acer japonica
Bamboos, such as Phyllostachys
Conifers, such as Chamaecyparis, Juniper, Pine and Yew
Cotoneaster
Euonymus japonica
Ligustrum (Privet)
Pittosporum tenuifolium
Prunus laurocerasus (Cherry laurel)
Rhododendron and azalea

http://www.amateurgardening.com 2012

This is my Copper Beech that has been lollipoped over a few years, in fact it is regularly licked into shape.