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What is happening at PF Olsen Nursery?

With the imminent start to the planting season, we are working hard to get the seedlings as robust and sturdy as possible prior to delivery to planting sites all over New Zealand.

One of the major jobs that has a bearing on the planting success is controlling the height of the trees via an operation called topping.

Topping makes seedlings more wind-firm by reducing the height of the seedling. Cultivation and planting depth is controlled in the field by the planter, however a tree seedling that is tall will stick further out of the ground and is more susceptible to wind after planting than a shorter stockier seedling. Having a higher "root to shoot" ratio also provides drought tolerance by reducing transpiration.

However the prime reason for topping seedlings, especially in a containerised nursery is to harden the seedlings off. This helps the seedlings to tolerate frosts and wind exposure as well as the stress and shock that goes with transplanting.

When arriving at the planting site, the ideal seedling will have the topping wound completely healed over with a small amount of new bud. The small bud will minimise risk of the sensitive growing cells at the top of the seedling exploding during a frost. The newly formed bud will respond quickly and grow when temperatures warm up. If the bud growth is too long it will be more susceptible to frosts and wind.

With so many things going on in forest nurseries over the winter season, it is important to give your selected nursery plenty of warning in relation to your planting date. This allows the seedlings to be correctly prepared, giving you the best possible seedlings and in return the best possible outcome to your planting programme.

Topping machine

The topping machine used at PF Olsen Nursery as shown in the photo above was designed and built by the Nursery Manager Kevin Haine. This has significantly reduced the time and labour input to top all the seedlings in the nursery. We can now time the topping for individual clients to meet their planned planting times. Kevin noted on a recent visit to containerised nurseries in Australia that they have used his concept and design to build their own topping machines for use in their containerised nurseries. Not often we can teach the Aussies something other than how to play rugby and rugby league.

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