The air might be cooling at this time of the year, but to the gardener’s benefit, the soil will retain summer’s warmth for weeks to come. If you don’t believe me, try dropping your daks on a crisp autumn morning and make contact between your bare bum and a bare patch of ground. Compared to the air temperature, the soil should feel warm. This technique works better in spring than autumn, but it was how they did it on the low tech days of old. Try it, but remember that bare bums and ground dwelling wolf spiders don’t mix! If you are the modest type (or fear spiders), try poking a finger in the soil. Better still why not save yourself, and the neighbours, from embarrassment and poke a thermometer into the soil.
The combination of warm soil but cooler air temperatures makes autumn the ideal time to get stuck into some planting. Evergreen trees, shrubby natives, hedging plants, perennials and spring bulbs can all go in now, allowing time for strong root growth before winter without the stress of hot air temperatures.
As well as planting out newly purchased or propagated plants, autumn is also the best time in the year to transplant existing shrubs, perennials and even small trees. Even experienced gardeners make the mistake of planting things in what turns out to be the wrong spot, but it’s hardly the end of the world. With care and confidence, most plants can be dug up and moved to a better location.
For small plants, transplanting is simply a matter of digging up, dividing if necessary, and replanting in well prepared ground. Evergreen perennials like bearded iris, agapanthus, and liriope cope beautifully with autumn transplanting, but it’s suitable for herbaceous types as well. Species geraniums, herbaceous salvias and other spring flowering perennials are actually better divided now than in winter or spring.
Woody shrubs are slightly more difficult to move, but not much. The three keys you need to bear in mind for successful transplanting are: (a) prepare the new planting site in advance, adding any soil amendments and having stakes and other materials ready to go; (b) keep as much of the plant’s root ball intact as possible and keep it moist by wrapping in damp hessian; and (c) water deeply after replanting using a seaweed extract to stimulate new root growth. There’s always an element of risk when transplanting, and the plant will usually experience some degree of shock at such invasive treatment, but if you do these three things your transplant should recover fine.
For larger trees, the first thing to determine is whether the plant is deciduous or evergreen. If deciduous, you’re much better off waiting until the tree is dormant and leafless before attempting the move. If evergreen, transplanting is basically the same as for shrubs, but requires a combination of brute strength and delicate treatment. As a rule of thumb, the younger a plant is, the better it will transplant. Unless you have access to specialised tree digging equipment, the risks will be greater than for small trees and shrubs, but so can the rewards. Besides the three rules mentioned earlier, there a couple more worth considering before you put spade to soil.
Firstly, it may pay to prune the canopy of a tree to be transplanted by up to fifty percent. This helps compensate for any roots that are damaged during the transplanting procedure by reducing transpiration. Secondly, newly transplanted trees will generally require staking for the first year or so after being moved. This helps anchor roots against strong winds. Thirdly, transplanted trees will usually need to be planted in a good sized hole (double the width and depth of the root ball) that’s backfilled with existing site soil. Backfilling with fresh compost or manure is a recipe for disaster. You should, however, ensure that the soil is broken up finely and firmed in to make good contact with the roots. This process, combined with deep watering, will help remove any air pockets which may cause roots to dry out and die.
Once you’ve got your plant in its new position, there is one final requirement: patience on the part of the gardener. This is standard practice for anyone working with plants and seasons, but is especially important with a new transplant. If you were suddenly uprooted and transplanted to a different home, you’d take a while to recover and so it is with plants. Don’t expect too much too soon. Use the opportunity to hasten slowly.
First published in the Toowoomba Chronicle 27th March 2010. Photo by Justin Russell – Queensland bottle trees at Crows Nest transplanted from Acland coal mine.
