1 Aug 2023

Gardening with Xanthe White: Winter work saves summer time

From Nine To Noon, 11:30 am on 1 August 2023

Everybody's garden is a mess at the moment, says gardening expert Xanthe White.

But as spring is just around the corner it’s time to tackle those weeds while the ground is wet.

But know your weeds, otherwise rather than weeding, you’ll be propagating, she says


Photo: Pixabay

“This is a time to get on top of all those things that have been taking over and slowly creeping forward”, she told Nine to Noon.

So how do you weed well without making things worse?

The advantage now as that because it isn't spring, most things aren't in seed, she says.

“And so, it is a good time to know that you're not spreading everything around and you're getting rid of things before they seed.

“I always say with that with the really icky weeds like agapanthus or Pampas grass and things like that try to take the seed heads off those before I deal with the actual weeds themselves.

“Because if you start digging the plant, you're shaking seed heads all around.”

Tradescantia also known as Wandering Willie Photo:

Weeds such as wandering Willie (tradescantia) convolvulus and kikuyu grass mustn’t go in the compost until they’ve been “cooked”, she says.

“With things like that, when you break them apart, you are essentially propagating them.

“And so those are the ones that instead of composting, they can actually end up taking over your entire compost, these little things that grow from the stems or the roots.”

She recommends putting these in a black plastic bag in a hot, sunny spot.

“What you want to essentially do is cook them. use the black of that plastic to put them into a really hot spot and just let them go to absolute rot, down to absolute mush.

“And then once they're all mushy, they can be composted.”

Weeds that grow from seed can be composted at this time of year as they have not set seed, she says.

Oxalis Photo:

Oxalis, the bane of many a gardener’s life, is best left undug, White says, because when lifted there is an “explosion of the little bulbs, it shoots them off into the soil.

“And so weeding oxalis is actually a really good way of propagating oxalis.”

Short of digging out all the soil and replacing it, it’s best to knock them back on their heels by cutting off foliage and shading them out, she says

“If anyone's seen oxalis in the garden, it will get very stringy in the shade. And so the most success is actually cutting back the leaves.

“So that diminishes its ability to replenish those bulbs.”

 One listener had grass establishing under camellias and rhododendrons.

You need to establish something else under there, things like clivia will provide you with really good cover, ringaringa will provide beautiful cover.”

Another was overrun with Arum lilies, get stuck into them now was her advice.

“This is a good example of the weed that if you leave a slice of that root in the soil, it will regrow again. So, when you're digging it out, you need to dig deep.

“What I do when I'm taking these out is I put my spade down into the soil straight and on the outside of the plant, and I lift up, and then I try to shake the soil off rather than chop the plant out.”

“So, you're trying to shake that soil off those roots.”

Now is also a good time to be transplanting trees and shrubs, she says.

“Most things you can move at the right time of year, and now is the right time of year, it's the right time of year because things are dormant.

“You’re trying to move the plants around when it's going to put the least stress on the plant.

“So, the slowest point of growth is generally the point where the plant is going to suffer the least stress, because it's not surging with energy upwards and downwards, trying to grow or trying to fruit or trying to flower.”

Remember when moving the plant to equalise the top growth with the root system, she says.

“If it's hard to get a good root ball on your plant, that's the area that you're digging out underneath the ground, then you need to reduce the top of the plant to balance it with the root system.”

A general rule of thumb is prune between a third to two thirds, she says.