Th Ex Factor

Is it a bird? Is it a plane?

Ever wandered down an avenue of super advanced palms or trees or a single feature specimen in an area that doesn't seem to be old enough to have had these statuesque plants growing there? Chances are the developer of this landscape wanted instant impact in their design, it grabbed your attention right? Bang for their buck right there.

After seeing these 'fully grown' plants, you've thought "that would look good in my front yard". Well if you've got the disposable income and the space/access then why not? An ex-ground tree or palm maybe the thing that sets your garden apart from your neighbours!

Trees, like the people making bourbon at the Jack Daniels distillery, aren't in that much of a hurry, in fact many of the 'giants' in your surrounds have seen generations of humans come and go, patience is their strong suit and if it isn't yours then you'll need to find something a little bigger than what the local nursery stocks.

So lucky for you there are people who looked into the future and put the wheels in motion to have  some super advanced specimens just for us who enjoy the mature look in the landscape. Chances are if you are after size, you'll need to get that plant out off the ground. Ex-ground, or field grown trees, come in all shapes, sizes and types and can be several years to decades (or even older) in the making. The age and type of plant can also make the price tag vary exponentially. The cost of digging, transport and transplanting should also be considered before making a purchase.

Hitchin' a ride

Field grown trees have the advantage of having 'room to move', that is they can spread their roots and therefore their canopy, attaining greater size then their relatives confined to pots. With the more advanced root system and canopy development, these plants can find and regulate their own moisture and food.

This can have a benefit in regards to associated costs that a potted production nursery may have to deal with over a shorter term. Also the in ground trees can tap into the earths "social network", that is they have relationships with beneficial soil organisms that aid in the uptake of water, nutrition and pest & disease defence.

Like in many areas of horticulture, there is a science to getting large specimen plants out of the ground. Removing a plant from the soil is a stressful task, not just for you but the tree as well. Now how and when you prepare the soil and roots for digging will change from species to species. Plants can either be evergreen (don't lose their leaves) or deciduous (lose their leaves) this factor will aid or hamper your transplanting.

Evergreen Trees can be a bit more stressed as their leaves will be actively transpiring throughout the year, but as a general rule it is best to transplant during cooler parts of the year, when daytime temperatures aren't too hot and nighttime temperatures aren't too cold. With deciduous trees, from the moment they've shed their leaves they can be moved with minimised stress.

There are a few 'rules of thumb' when it comes to digging up a tree. For example, for every 25mm of trunk width (calliper) you should allow around 200-300mm of root ball radius. This rule isn't so hard and fast. For example, palms - which are one of the most commonly transplanted plants, can get a surprisingly broad trunk and large specimen with a rootball dug out at around 1 metre cubed.

"A little to the left"

For trees in leaf at the time of transplanting it is advantageous to reduce the volume of the canopy, that is reduce the amount of foliage via pruning. This action can help reduce water loss through the leaves. There are also anti-transparent's that can be applied a foliar sprays that coat the leaf in a way it lowers the movement of moisture and oxygen from the leaf surface.

The soil surrounding the plant should be kept moist prior to digging, this will allow easier removal from the ground but also ensure the trees hydrated enough prior to removal. This is more important in the case of evergreen trees or deciduous trees that are in leaf at the time of transplanting. During transport, plants with leaves still present should also be covered or wrapped to alleviate the drying impacts wind/air movement can have.

Convoy!

In this technologically advanced world we have wonderful devises that will take a tree out of the ground with minimal fuss, lower physical human labour input and less 'down time' from digging to transplanting. It's a pretty cool process and these modern tree diggers make it look super easy, check out this educational video here.

Transplanted specimens from specialised in ground growers generally come wrapped in hessian, a practice know as "bagged and burlapped". This hessian wrap helps keep the rootball and soil intact as much as possible, it also helps the soil retain moisture. 

Ideally should be installed into their new home as soon as practically possible after being dug, this will lessen the transplant shock and set back that is to some degree always present. Evergreen trees will need more attention. Anti-transparent's can still be applied throughout this process and there is also root hormones and beneficial soil organisms available that are added to the soil to stimulate root growth and speed up the established period. 

"Now what do we do with it?"

In ground tree growing and transplanting plants are a specialised area, where plant selection,  production planning and site preparation is very important. The logistics of moving these semi mature specimens is nothing short of amazing, so be prepared to pay for the privilege if it's an avenue you'd like to go down. 

So next time you walk past any of the  Livistona australis (Cabbage Palm) at Barangaroo on Sydney Harbour or an avenue of of large Ulmus sp. (Elms), Fraxinus sp. (Ash), Platanus sp. (Plane Trees) or Pyrus sp. (Ornamental Pears) in a new housing development or streetscape in Sydney's North or South West, stop and think, they may have travelled a long way to get there and seen more than you during your lifetime.