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Mya’s harbour-saving message on open-ground

by 10 Apr 2011Cartoons, Establishment trials4 comments

I am explaining the importance of open-ground plants…

…because I think open-ground is the best way to provide plants to plant along the edges of rivers and streams.

Mya Cole

Mahurangi Mya: A student of Mahurangi College, Mya Cole has studied open‑ground (forestry‑style) plants for her Waicare project. photographer Liz Cole

We need these areas planted to protect the Mahurangi’s benthic community, which are the horse mussels, cockles and other animals living on the bottom of the harbour.

It benefits the benthic community because when it rains, trees help to stop this happening, and they stop valuable soil being washed away. We also need trees beside our rivers to give shade to macroinvertebrates so they don’t get stressed and die.

Fencing is important to prevent farm animals trampling all over the stream killing macroinvertebrates and pushing soil and mud into the river, which will also choke the benthic community. Open-ground plants are plants that aren’t grown in containers. I think growing plants in open-ground beds are better.

Open-ground plants are different from those grown in planter bags, pots or root trainers. They are grown in open-ground beds and, because they have more space, they grow much stronger, faster and healthier. The roots of planter‑bag and potted plants, when they reach the edge of the container, start circling around the edge of the container trying to find a way past it. They keep circling around getting tangled. So when you plant them out, they can sometimes later fall over because their roots can’t hold the tree up properly.

Whereas open-ground plant roots don’t circle, because when they are being grown in the nursery their roots don’t go around and around a container—there is no container, they are in the open ground. Because there is no circling, the roots have a better chance of supporting the tree above.

Open-ground root system comparison with container root circling

Roots Straight, Roots Circled: The open-ground plant on left displaying roots mechanically pruned rather than constrained to circle endlessly inside its plastic container. photographer Jonathan Barran

The price of buying open-ground plants is also much cheaper than container plants.

Radiata pine open-ground plants cost about 30‍ ‍cents each, but container plants can cost $3 each. If we brought open-ground plants instead of container plants, we would be able to buy many more plants and be able to help more waterways. Also, because open-ground plants grow faster and stronger than container plants, you get more successful trees.

Most open-ground plants produced are exotics, grown for forestry use. However, two companies are growing indigenous plants open-ground. The nearest is Taupō Native Plant Nursery’s new nursery at Glenbrook.

So, planting with open-ground plants is cheaper, the plants are stronger and less likely to fall over. Also their roots are stronger and you can buy more of them for the same money.

Open-ground plants can mean healthier waterways and flourishing benthic communities.


See alsoOpen-Ground Indigenous Plants Report