by Francois Krige

Some of the trees we have felled this summer have been in my care for more than 30 years. It is really sad to see so many dead and dying European oaks in Rondebosch, Newlands, Claremont, Kenilworth, and Wynberg. There is the occasional tree that appears resistant, or at least much less attractive to the beetles than its neighbours. Time will tell whether there are truly resistant European oaks in the suburbs. Feedback from Vergelegen, where Richard Arm is the horticulturalist, is that the fatality rate is around 90%.

We are seeing early signs of the disease in oaks in Constantia and Bishopscourt. It is at the doorstep of Kirstenbosch, probably already present in the oaks at the stone cottages opposite, and has been identified in the City Bowl and Hout Bay.

The important thing to note is that this is essentially a fatal disease in two species: Acer negundo (box elder) and Quercus robur (European oak). Many other species are affected but survive. Plane trees, for instance, are severely attacked—the streaking on the smooth parts of their bark is clearly visible—but they generally do not die from it.

I can confirm that we have now felled many dead trees that had received expensive “treatments”, and these treatments only added to clients’ despondency when they still had to pay for the removal of a dead tree. I have also heard many claims of successful treatments where untreated trees of the same species nearby survived. These species include planes, willows, coral trees, poplars, and other varieties of American oaks. “Curing” trees that are naturally resistant is good money.

When working within the infestation zone, it no longer makes sense for the entire tree to be processed and stockpiled on site, or taken in a closed vehicle to the incineration plant. The beetle is widespread, and the transfer station and the transport route to the composting site on Varkensvlei Road in Philippi are all within the infestation zone. If a client insists on us adhering to these outdated protocols, we will do so.

Whenever we work outside the infestation zone, we take all precautions to ensure that contaminated materials or equipment are not transported. Krige Trees has been investing heavily in equipment upgrades to safely fell brittle oaks, including cranes to suspend our climbers and cranes to support the material being felled.

The best advice to clients, however, is to fell European oaks sooner rather than later once they become infested—especially if the tree is in an area where the beetle has recently arrived. If your tree is showing dieback, it is clearly one of the more susceptible individuals, not one of the very small number of resilient trees. It is almost certainly going to die.

The timely felling of dying oaks is important to reduce the risks to people and property during removal. It also has a significant impact on the cost of the job. Weak, brittle trees require far more skill and time to fell.

This work has had a big impact on us as a company. We do not relish the fact that we will be felling hundreds of trees that were planted by our grandparents’ generation. To our clients, we would like to say: you enjoyed a tree that you did not plant; it is now time for you to plant for future generations.

Our tree nursery at Platbos Forest has been expanded to meet the needs of a city that will be partially denuded by this disease. I am growing many thousands of Celtis africana (white stinkwood), Apodytes dimidiata (white pear), olives, beech, Cape ash, water pear, bladder nut, and many others.

Any tragedy holds the seeds of opportunity. We need to be remembered as the generation that replaced the oaks—not the generation that felled them and left their stumps lining sun-baked streets and dotting gardens where avenues and shady spaces once stood.