It may have seemed a good idea at the time but, perhaps because of redevelopment or change of use, those trees are now in the wrong place. Or perhaps the trees are simply too close together and there is an opportunity to redeploy these valuable assets over a wider area. With today's equipment, techniques and expertise, it is possible to move big trees and move them with a good chance of success.
Civic Trees, part of Glendale Countryside, and Nature First of Gloucestershire are two companies with considerable experience of relocating large trees. Both operate nationwide. Civic Trees sales director Deric Newman and Nature First director Karl Stuckey offer tips on how success can be achieved.
1. PLAN IT
If the relocation of trees can be planned in advance, they can benefit from being prepared and the chances of success are increased. Seek advice as early as possible and use a reputable company to move the trees.
2. CONSIDER THE SITE
Think about where the trees will be relocated. If trees can be moved within the site, rather than to a new site, there are efficiency and greater savings to be made. "Where there is a supply of trees on site, say a golf course, but they are just in the wrong location, you can move them within the site using a tree spade and that can work out at about the tenth of the cost compared to buying in similar trees," says Stuckey.
Any saving will decrease the further the tree has to be moved because the operation will take longer and require more work and equipment. Larger trees will need more preparation to increase the chances of success.
3. MOVE AT THE RIGHT TIME
For a higher chance of success, big trees should be moved in the dormant season - November to March. "During the dormant period trees can be moved easily with little or no stress on them," says Stuckey.
4. TREE SELECTION
Sometimes it is necessary to decide which trees to relocate, which to leave where they are, and which to lose. Where there is a choice, opt to move trees that are the best shape. Stuckey suggests trees on the outside of groups or wooded areas should be considered first, rather than looking to move any from within the group or wood.
"The outer ones are normally a better shape, will be used to the wind and will have more root system. Since they are less crowded, they are also easier to move and will come out quite easily without damaging others. Those within the woodland will be taller, have less shape to them and have shallower root systems," he says.
The choice of tree or trees should also take account of ground conditions and access when reversing the vehicle to pick up the trees for moving. Temporary road ways can be put in place to overcome poor ground conditions, but adds to the cost.
5. PREPARE TO MOVE
Time is often a luxury when it comes to relocating big trees. Where a site is being redeveloped, there may be no time for any preparation work but where it is possible to plan in advance, root pruning will help lessen the shock of being moved and increase the chances of success.
"If you know a year or so in advance that a tree will need moving, you can go in the previous winter and prune the roots by a third or a half - depending on the tree and the site. By doing the root preparation, you start off new root growth and the tree creates new roots the summer before it is moved - then it is already benefiting from new root growth back inside the rootball when you come to move it," explains Newman.
In an ideal world such preparation work would be completed over a period of three years prior to moving the tree. In this way a new rootball can be created; but such an opportunity rarely arises. Tree surgery can also be considered. Reducing the canopy will help compensate for the lack of roots where no root preparation work has been possible.
6. SIZE OF EQUIPMENT
It is important to use the right size of tree spade for the size of tree. The girth measurement is the all important statistic. As a guide, a tree with 150mm girth will require a 1.6m tree spade, but the species of tree and its state of health should also be taken into consideration.
7. PLANTING PIT
Put a little compost into the pit and around the edges before settling in the rootball. This will give something nutritious for the roots to grow into.
8. SECURE IT
Simply because the rootball fits into a hole of matching size does not mean there will be no movement. The bigger the tree, the more likely it is to require guying. "Big trees are likely to suffer more movement in the wind, and that will sheer off the developing roots," explains Newman. Underground guying may not be practical unless the rootball is in netting, so it is more common to use an overhead system.
"Typically we use overhead guying and then, where there is public access to the site, we sheath the wires with yellow hose, rather than black. We may also put in a knee-rail around the pit. This also has the advantage of stopping the grass maintenance vehicles going too close and snagging the wires. It's added protection," says Newman.
9. MULCH IT
Using organic, loose mulch around the tree after planting will help keep moisture in the ground and keep the weeds down around the tree. The mulch will gradually break down and by the time the tree starts to take in nutrients, some nutrients will have begun leaching from the mulch and provide a valuable source of food.
10. WATER IT
It is essential to provide the tree with plenty of water for the first couple of years that it is in its new home. The main reason for trees dying is insufficient water, especially in the first season after planting. Without further costly excavation, it may not be practical to install ring-type irrigation systems around the trees so be prepared to transport water to the trees.
In order to encourage the roots to explore, Stuckey prefers to drench the tree, let it dry and drench again. Newman agrees: "Make sure it gets plenty of water in the first two years but in such a way that the roots will be encouraged to venture out and look for more."
Last winter Civic Trees, a division of Glendale Countryside, acquired an off-road 2.1m tree spade. It enables trees of up 800mm girth to be moved and, being mounted on a six-wheel-drive dumper truck chassis, has "go-anywhere" capabilities to reach trees in difficult locations. The Vermeer TS84 is the company's eighth and largest tree spade to date.
"We opted for a unit with unique off-road capability so that we could solve access difficulties for our customers and give opportunities to move trees that have previously been considered out of reach. The Volvo platform is one of the most reliable," explains Glendale director of arboriculture Jonathan Hazell.
Civic Trees has recently been working in Manchester where the local authority identified some trees that could not be retained as part of a redevelopment scheme. Newman says: "With forward thinking, the ouncil's landscape team identified more than 20 trees that could be moved out into the parks."
A mixture of broadleaves, some cedars and Acer griseum specimens were moved. Some of the trees were lifted using a 1.4m tree spade and were rootballed on site using wire and Hessian wrap before being transported to the new sites. A 1.5m tree spade was used for the larger trees. These were transported in the tree spade. "It's not practical to rootball this size of tree because the rootball wire isn't strong enough," explains Newman.
Everything that could be moved was moved. "We were relocating trees with girths up to 900mm," says Newman. "In some cases we did some tree surgery to reduce the root/shoot ratio of the trees because there had been no time to prepare the trees in any way ready for moving."
In another scheme, Civic Trees used its new 2.1m tree spade to move trees to create parkland from what was previously an arable field.
Encouraging roots to grow deep and remain below the surface is essential if newly planted trees and shrubs are to become healthy and strong. The Hunter RZWS Root Zone Watering System is a new watering device designed to put the water where it is needed.
RZWS consists of a series of internal baffles within a rigid cylinder shape. The baffle system distributes water to both near-surface and deep roots. The units come in 25cm, 45cm and 91cm lengths and with two pressure compensating bubbler options. They are available from Evenproducts.