Plant Doctor Archive

 I HAVE a small established area of native plants (an old bush house) in my garden, which have come under serious attack from ivy and jasmine. Included in the area are mature pittosporums, titoki, wineberry and a nikau palm. Also ponga, which are the main victims of the ivy at the moment.

I read the War on Weeds articles on these two weeds with great interest and wonder what precautions I could take to protect these plants, particularly the nikau and trees, if I was to take the chemical control path — assuming there is anything I can do to protect them. I think the ponga will probably be lost, they are so badly covered, but the nikau is still clean and I particularly don’t want to damage it or the other trees.

 I ASKED Reg Lewthwaite, horticulture lecturer and expert in sprays, for his advice. Reg suggested that for a small area the first thing to do is to physically remove all the weeds that you can. This will minimise the use of chemicals and also let you separate the weeds from the native plants. Make sure you remove any small stems and fragments as they will grow into new plants.

For a long-term solution you can establish selected plants that provide dense shade, which will suppress weeds.

Then, if you need to, you can use an agrichemical to get the little bits that remain behind and regrow as soon as you turn your back. Reg suggested trying out ‘Vigilant’ which comes in a small container and can be wiped onto the cut stems. It can affect the soil and desirable plants, so use as little as is needed to cover the cut.

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