Rain, Rain, Go Away, Come Back Another Day

Posted on May 29, 2020

Somebody had forgotten to tell the rain to come back! This week is the first time we have seen the water rise in the creeks and some colour in the water after 48 hours of intermittent rain. The drought has eased finally.

The drought is a serious one for the north island and it is especially bad in some areas like Northland, Auckland, Waikato, Bay of Plenty, Central North Island and the Hawkes Bay.

The drought for some is the driest it has been since World War 2 which is a long time if you consider ¾ of a century a long time. Philip Duncan, the weatherman, puts it simply that we need to have double our rainfall averages over the next few months to catch back up again. That is a lot of rain.

In our space, in the plant world, we tend to keep a close eye on things like the weather. Last summer was also dry which has compounded the severity of this summer and now the moisture levels are very low in the soils and groundwater. There are dry water bores in Northland that have never dried up prior to this Autumn.

The shortest day is this month and the frosts have turned up. This does not make good news for the much needed grass growth. Our farming community that are buying feed from the South Island are paying top dollar. Just a few years ago the Hawkes Bay farmers were sending truckloads of almost free feed down to the drought areas of the South Island. Obviously, a few short memories out there…

Trees and shrubs have been greatly affected in the landscaped urban areas. This is a bit of an interesting sight when you start looking at species like Griselinea littoralis. There is hardly a hedge in the north that hasn’t had die-back or worse still complete wipe out. What now for hedges? It is hard to replace such an easy choice. There are some out there that have a view that Griselinea is overused in Auckland and now they have another string to their argument.

Quite a few commercial landscapes around buildings and car parks have some very sad looking gardens. This will be welcome news for landscapers seeking prospects, but not so encouraging for the landowners. Some will be reaching for their insurance fine print and seeing whether the Force Majeure clause can be expediated.

Probably the most concerning element of the drought is something that those in the seed collection space have seen all over the place. It is the dead canopy and understory in the forests. Some of the Kauri forests in the north are particularly bad. It is a sad sight and it will cause further stress and damage to the root systems of these mighty giants. In fact, with the Kauri Die Back testing, it is revealing a high number of stressed trees are likely to be the results of dry conditions and the competition for available moisture in poor clay soils. The Kauri tree is a surface feeder and has extensive shallow root systems.

Some of the large stands of Taraire around the north have old mature specimens dying. An easy place to see this is in the native bush stands just south east of the Puhoi tunnels where over 50% of the tree canopy is dead. The exaggerated colour picture below shows the extent of this.

The seed collection for some tree species has been impossible. The seed has obviously stopped maturing and is infertile. Rewarewa has been particularly difficult to find this year. The range of mature native plants in their natural environments that have died is incredible and the Central North Island has been damaged significantly.

You can see native revegetation plantings that are anywhere from 2 to 15 years old and a number of plants amongst them have died. Many of these projects have matured beyond the important project preparation of mulch and good topsoil layers. The drought is hitting established root systems.

We could safely say this is a 1/100-year dry summer and it has forced us to step back and look at the plant palate we are using and evaluate whether we could do better? It is interesting to see the hedges that are doing well while the Griselinea is failing. These are Camelia, Ficus Tuffi, Sygizium. For commercial grasses in the car parks it is noticeable that Lomandra hasn’t been affected hardly at all. It is a very tough plant.

We would love to share any feedback and experience that you have had coping, or not coping with the dry period. Talk to our team about what your opinions are of the best hedges as we would love to know.