Plant Doctor Archive

Spreading alstroemeria

A LONG time ago I was given a root of alstroemeria. Unfortunately, it has spread and I've spent hours trying to get rid of it, but every piece of root I miss grows again. What can I do to get rid of it?

ALSTROEMERIAS can be great garden plants, as they flower over a very long period, but, as you've found, some can spread and be difficult to control. The red parrot beak species, Alstroemeria pulchella, is one that can be hard to get rid of once established.

Apart from trying to remove every piece of root by hand, the next best thing is to try a weedkiller such as Activated Amitrole or Escort, which is absorbed into the foliage and taken down to the root system. For best effect, I recommend you apply the weedkiller mid to late summer when there is plenty of foliage on the alstroemeria to allow maximum uptake of the active ingredient.

To avoid getting the spray on nearby plants, you could paint it on the alstroemeria leaves with a brush or sponge, but make sure to wear protective gloves. Try to apply it to as much of the foliage as possible.

Don't expect instant results - these sprays take some time to work and you might not notice the full effect until next spring. You may also have to treat the odd bit of regrowth that occurs, but it should save you a lot of arduous digging.

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.