21st August 2017- By Sally Drury
Choosing the right plant, correct planting procedure and best aftercare are the three basic rules for successful tree planting, Sally Drury explains.
Arbor Day. In China it falls on 12 March, Pakistan on 18 August, New Zealand on 5 June and the Czech Republic on 20 October.
In Brazil it’s called Dia da Arvore and is held on 21 September. In Germany it is Tag de Baumes and on 25 April. Australia has a National Tree Day in the last weekend of July. Trees are celebrated around the world and ArborDay, begun in Nebraska City in 1872 by J Sterling Morton, is a time when individuals and groups are encouraged to plant trees.
In the UK we mark the start of the winter tree-planting season with National Tree Week, seven days in which around a million trees are planted by schools, community groups and local authorities. Many more are planted throughout the year by landscapers, contractors, estate owner, local authorities and developers.
Three basic rules
Yet, while tree planting is recognised as important, there are still many examples of bad tree-planting to be seen, even though there are only three basic rules of right plant, correct planting procedure and best aftercare. Right plant means selecting trees of appropriate type and size for the planting site conditions — observing soil, moisture and climate dislikes and preferences as well as considering likely exposure to wind and salt spray. Hopefully we have seen an end of Quercus robur being planted on tiny roundabouts.
Planting operations take just as much consideration. If the soil is poor, it might be worth looking at replacement with better soil or mixing in tree-planting composts. Topsoil, a division of British Sugar, supplies HortLoam BS3882:2015 compliant sandy loam planting topsoil. With reserves of organic matter, in the form of PAS 100 compliant “green” compost, and nutrients, it is said to be ideal for planting root ball trees and shrub beds as well as retained planters and vegetable planting projects. Free from diseases, building material residue, invasive weeds and pesticide contamination, HortLoam has a typical percolation rate of 1.44mm/h and its open structure encourages healthy root growth.
Meeting the same BS3882:2015 standard, Green-tree Top Soil from amenity supplier Green-tech is manufactured from natural by-products of the recycling industry and is packed with essential nutrients and structural components to give a rich and organic growing medium.
Its high fertility is formulated to give quick establishment of trees — also shrubs, perennials and turf — without the need for additional fertiliser in the first season. Green-tree was used at the Olympic Park Legacy and South Tyneside Regeneration projects.
Designed for urban environments, Green-tree Amenity Tree Soil, also from Green-tech is a load-bearing, fertile planting medium that allows the development of tree root infrastructure under hard surfaces such as pavements and car parking areas. It has a naturally open structure, a typical pH value of 7.8, percolation rate of 53mm/h and, with a sub-rounded particle shape, allows oxygen and water access to the root system.
Yet another specialist growing medium from Green-tech is ArborRaft Soil. Developed for the UK market, this medium works as a root zone with the ArborRaft system and ensures structure remains open and that the correct levels of water, air and nutrients can move through the soil to the tree roots.
In September Green-tech is adding another product to its extensive tree-planting catalogue. Marketing manager Kate Humes explains: “TerraCottem Arbor is a physical soil conditioner designed to increase the water- and nutrient- holding capacity of soils and growing media.”
“TerraCottem Arbor has been developed to increase the plant’s root development, growth and survival rate, and reduce the need for watering by up to 50%.”
A full launch, including introductory promotional offers on TerraCottem Arbor, will be available from Green-tech at the start of the new planting season.
Autumn also sees Green-tech deliver its 2018 catalogue, crammed with more than 6,000 products.
Additionally, a new tree-planting brochure is expected to coincide with the planting season and will include all the tree-planting essentials and accessories needed for the forthcoming season.
It is best to wet root balls and containerised plants prior to planting, leave hessian and/or wire in place on root balled trees and then plant to the right depth. It seems to be staking that still causes horrors, although there is plenty of advice and, again, the rules are simple. For bare-root trees up to standard, use a single stake placed on the side of the prevailing wind to avoid chaffing and extending one-third to halfway up the tree trunk.
For container-grown stock and root balled trees, use double staking with crossbar, multiple staking, overground guying or underground anchoring methods so there is no need to drive a stake through the roots. There are plenty of options when it comes to tying trees to stakes, but nailing the trunk to the stake definitely is not one. Buckle tree ties and spaces are popular because they make it easy to adjust the tie as the tree trunk expands with growth.
English Woodlands Burrow Nursery in East Sussex has been supplying plants and accessories to landowners, landscape contractors and local authorities since 1919. It reports a growing interest in hessian tree ties (pictured above).
“We are finding more and more contractors and local authorities are using hessian tree ties on the roll,” confirms sales director Jo Carter.
“It is cheaper than rubber and biodegrades naturally in 18 months so there is no chance of the trees being strangled and it cuts down on maintenance visits. It can be used for securing all sizes of tree.”
Also proving popular at English Woodlands, and making a finish to landscape schemes and tree planting, is metal edging.
“Our metal edging is extremely popular at the moment in both aluminium and steel,” says Carter. “They provide an effective, contemporary boundary separating different materials and look equally smart in an urban or private setting. There are edgings suitable for soft and hard landscaping in linear or curved applications. The tree rings are easy to install and come in brown, black or galvanised finishes as standard.”
Depending on the stock and the location, some form of protection may be needed to keep the newly planted tree safe from traffic and pedestrians in urban areas, and from wildlife and livestock in more rural sites. See p58-59 for details of tree guards and shelters.
While they make an instant and dramatic impact, big trees along with the larger hedging plants can be expensive to buy, transport to site and plant. On some sites, notably golf courses, estates and in municipal districts, it may be possible to select trees from part of the site that is overcrowded or where other uses are intended in the future, and replant the trees in a new location. It is best to call in the specialist service of tree-moving firms, but even taking their costs into account, substantial sums can be saved over purchases of nursery-grown stock and it could save trees that might otherwise have been felled.
However the trees were obtained and for whatever purpose they were planted, the aim is to ensure growth to maturity. That is where the third element comes into play, that of aftercare.
In the first two seasons, watering is essential, perhaps through systems such as Green-tech’s Mona Relief tree irrigation products. Weeds should also be controlled around the base of trees to eliminate competition for water, nutrients and, in some cases, light.
Controlling weeds by mulch or herbicide application also reduces the need to mow or trim around the trees, hence eliminating the risk of mechanical damage. Tree ties should be adjusted as appropriate and non-biodegradable guards and shelters removed when their work is done.
A day may be set aside for community and commemorative planting, but the work does not finish with the process of placing the tree in the ground, it is just the beginning.
Tree relocation: optimal times and conditions September to March provides optimal conditions for relocating existing specimens.
There are many reasons why trees are lifted from one site and replanted in another. Ruskins Trees co-owner Robert Wilkins explains:
“Private clients might be looking for screening or they might use tree moving in preference to thinning by felling and move trees to create instant avenues and add interest to empty space.”
“Developers are also looking to use large trees for screening purposes and to adorn their final landscapes. Sometimes trees need to be moved to give access or create land to be developed. Local authorities will also relocate trees in order to allow development work.”
One operation saw Ruskins move a 40ft tulip tree (Liriodendron tulipifera) that was preventing a crane from being dismantled after it had been built around. Once the crane had been removed, the tree was returned to its original location.