Good weed control is essential for successful establishment and quick initial growth.

Trees planted and then left in a thick sward of grass and weeds will struggle to remain alive, often dying due to moisture competition in a dry summer.

In the 12 months before planting, two applications of Roundup should be applied, to kill all perennial weeds such as twitch and yarrow. Any draining or ripping needs to be done during the summer.

Following planting in the winter, apply a 1m-diameter ring of suitable mulch. This will conserve the winter soil moisture, and form a physical barrier to stop the seedling weeds germinating. Spread the mulch 10cms deep leaving a 5cm-diameter area clear of the trunk.

A further 30cm spray ring will keep invasive weeds from growing back into the mulch ring. If mulch is not available, then keep the planting site free of all weeds using a contact herbicide such as Buster or Galant. Roundup is easily translocated into the plant, so the use of Greenguard plastic spray guards will protect the tree stem. Residual herbicides rely on a barrier of chemical to stop weeds germinating, however many trees are sensitive to these products.

Always seek local advice before using herbicide spray products.

FERTILISERS

The application of fertiliser at the time of planting is not considered essential on farm sites and the fertile soils of some regions of New Zealand. However, on the more infertile soils additional nutrition combined with good weed control results in huge benefits.

Local deficiencies such as boron and magnesium need to be corrected in combination with a more general balanced NPK fertiliser. A 25 gram measure is placed in a spade slit 15cm on each side of the stem on the same contour.

FERTILISER TABLETS

The convenient 10 gram or 21 gram Agriform tablets offer a measured dose of NPK with the nitrogen in a slow release form of urea.

Contact your local fertiliser company representatives for soil testing and fertiliser recommendations.