How to move garden plants

You might think that someone who has made a living from gardening for the past thirty years would always set a plant in the right place. Well, I hold my hands up now and admit that I don’t always get things right. For example, a few years ago I planted a small cut leaf black elder fairly close to a hardy Japanese banana.

Of course, the small elder swelled in size and so did the banana, forming a gorgeous grove of five stems. Unfortunately, the elder spoiled the look of my stand of bananas, so I bit the bullet and decided I would dig up the shrub and move it to a more suitable location. Two years on, and I’m happy to report that both plants are thriving (the main image shows the cut leaf black elder in its new location).

Reasons for moving plants

As gardening columnist with The Mail on Sunday, I get a lot of emails asking me how to move plants, a process horticulturists call transplanting. Like me, some want to move a plant because it’s crowding out another but the majority want to move something because it’s outgrown its position or is not doing well in a particular spot. A few are upping sticks and want to take a cherished plant with them. 

What can I move?

Perennials, grasses, climbers and many other plants respond well to being moved. As a rule, most trees and shrubs under five years old should be relatively easy to transplant – older specimens will be bulkier and have a more extensive root system, making them harder to remove and replant. However, sometimes it might be necessary to give it a go, just be aware that there’s a greater risk in doing so. 

What hates to be moved?

Some plants resent being dug up and moved. Oriental poppies, peonies and sea hollies are among perennials that form long tap roots, which are easily damaged when you try to lift plants from the ground. I’ve been asked many times over the years if it’s possible to move cabbage palms (Cordyline australis). Again, these form deep tap roots and as a result, it’s very difficult to move them successfully.  

When to move plants

Timing is everything when it comes to transplanting. Most plants are best lifted between late autumn and early spring, while they are dormant. During this window, roots have a chance to re-establish in the ground before bursting into growth. Even so, plants may still sulk for a season before normal growth resumes.

Evergreen shrubs are best left until early spring. If they are moved in winter, plants often dry out because roots are unable to take up moisture to replace that which is lost through leaves. However, in spring and the arrival of the growing season, roots are able to take up water from the warming soil, helping plants to establish quickly.

Avoid moving plants in summer if at all possible. Being hoicked from the ground during hot, dry weather is stressful on plants and they’ll respond by wilting or shedding leaves. It’s important to remember that generally plants lose about a half of their root system when being moved and so they find it difficult to take up enough moisture to support above ground growth. That means you need to keep an eye on them and if it doesn’t rain, you need to water them.

How to move a shrub

Start by digging a 30cm (12in) deep, circular trench around the shrub, using the spread of its branches as a guide to where to dig. Undercut the core of soil with the aim of removing a large root ball – use the spade to slice in at a 45-degree angle, working around the base, and gradually tunnel underneath. It’s inevitable that you will severe some roots during the process.

Lift and wrap the rootball with a garden sheet to prevent roots drying out. Dig a new planting hole that’s the same depth as the rootball of soil and about twice as wide – spread some Root Booster in the base to help roots establish. Lower the rootball into position and fill gaps around the outside with soil, firming down as you go to eliminate air pockets. Water well.