Wednesday, February 3, 2016

High mortality rate: how we're going to fix it (2)

The tough, UV-resistant watering well we install around our trees (see yesterday's post) is a crucial part of our system and warrants further comment.


The well holds a lot of water
The diagram below shows how we plant our trees 100mm below existing ground level. That's not enough to cause a problem for the tree but it is enough to make the total volume of the well over 50 litres when you factor in the 100mm that protrudes out of the ground.

Tip: click the diagram to enlarge it

Perth Street Tree Standard Planting Configuration

The well keeps competing grass away from the tree
The negative impact of grass on young trees is greatly under-estimated. Time and again I've seen young trees suddenly take off once the grass around them is sprayed out and mulched. Grass is a voracious consumer of moisture and nutrients** and keeps young trees stunted.

The well keeps whippersnippers away from the tree
You only have to look at the pictures of whippersnipper damage here and here to realise how important this is. And these wells are tough. Regular whippersnipping of the grass around them won't affect them.

The well acts as a mini-windbreak
This doesn't sound like much but it actually makes a surprising difference to how quickly the soil around the tree dries out.

The well holds the mulch permanently in place
The most important contributor to a permanently moist root ball (other than watering) is mulch and the well keeps it permanently in place. We also include a loose plastic collar around the tree to keep mulch from contacting the trunk and causing collar rot.

The well looks good!
The well keeps everything neat and aesthetics are important. Residents are more likely to take an interest in their tree if it enhances, rather than detracts from, their home.


Coupled with our revolutionary new water truck, we think this set up is going to make high mortality rates a thing of the past for our customers.

If you'd like a trial at your Council - or simply want to find out more - email me. 

* The well is conical, meaning it is broader in the base than at the top. This is what gives it a deceptively large volume. It's also what makes the well difficult to pull out of the ground - that, and the angled stakes. And there's another important thing the broader base does: it wets a larger diameter circle than what you see at the top. 

** This is particularly the case with the vigorous, warm season grasses found in Perth: Couch or Bermuda Grass (Cynodon dactylon), Buffalo or St Augustine Grass (Stenotaphrum secundatum) and Kikuyu Grass (Pennisetum clandestine)

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