Trees - Treemendous Advice

During the 60s and 70s the planting of fast growing species of poplar became very fashionable with local authorities and the trend soon spread to golf courses. The fast growth and potential size of the mature tree seemingly being the answer to all the problems that golf clubs faced from members wanting instant results. How often am I faced with the question, 'Why don't we plant large expensive root ball trees or species such as poplar or cypress which grow quickly?' The answer is simple, short term fixes are never long term solutions. If a tree grows quickly, then it will normally have a short life span and the club will be faced with the same problem in 20 or 30 years. If large root ball trees are planted they will normally remain dormant for a good few years, allowing smaller stock to overtake them in a relatively short period.

The result of such planting is often homogenous stands of even-aged poplar, which then become the main management concern of the golf course. A common sight on many courses is the ubiquitous line of poplar around the boundary of the course which now is becoming a liability to both the club and its neighbours. Today it is even more important not to be seen as negligent with the growing American trend of liability claims.

Commercial hybrid poplar have a rotation age of 40 years which means that beyond this point they will deteriorate very quickly. They will drop twigs and branches creating a possible hazard to both players and neighbours and often suffer from disease or fungal invasion. Poplar canker is the most common ailment. This predisposes the tree to snapping at the weakened point. Further, poplar is surface rooting which often results in damage to expensive machinery or disruption to neighbouring property.

It is often mistakenly thought that the poplar will solve drainage problems by soaking up water in wet areas. Although they have a high demand for water, short mown grass will normally require more water than a tree. Further, poplar will always find the easiest source of water, normally field drains, and will thus compound drainage problems by creating blockages. It is not uncommon to find 20m. of fibrous root completely blocking a drain. Poplar roots can be found at a spread of up to 2.8 times the height of the tree and, therefore, extensive damage can occur in areas thought to be well removed from the tree's influence.

Both from a landscape and conservation point of view, poplars have little value. Their shape, texture and colour all contrast with the native trees of the broader landscape. Their existing root system can create a long term management problem as they will regenerate aggressively from anyremaining plant tissue, often to the detriment of any replanting as they will compete for water and nutrient.

Finally, poplars in the wrong place can have a significant effect on the ecology and playing characteristics of the course. White poplar was planted on many coastal courses due to its hardy nature. Unfortunately it is also an aggressive pioneer and will reproduce from its roots in the form of suckers quickly colonising the dune systems and shading out the native grasses which initially attracted golfers to the site. The result of their presence is a reduction in the quality of both the golf course and the ecological value of the site.

The removal of poplars is often an expensive project for they have little timber value and are therefore expensive to remove. In order to ensure that more desirable vegetation can be established in their place it is necessary not only to fell the tree, but also to remove as much of the root system as possible. This will avoid regeneration from any remaining plant tissue. Depending on the site and the species of poplar, this may entail felling and grinding the stumps or the mechanical removal of both tree and the root system by either winching or dosing, the latter being more appropriate to the removal of white poplar from sandy sites. It is not possible to be categorical as to the best method to deal with the problem without assessing the site and species involved. However, it is certain that, due to the aggressive nature of poplar, it would be wise to allow for a programme of spraying to stop future recolonisation from sucker growth.

In conclusion, I quote the words of the great golf course architect, Alister MacKenzie, 'Perhaps the most serious mistake made by a golf committee is the fallacy that they will save money by neglecting to get good advice.'Col/Architect 1920

John Nicholson, of John Nicholson Associates Arboricultural Consultants, can be contacted Tel: 0191 384 2556