In the natural world, grass plants will grow tall and produce seed to reproduce which is basically their sole intention of being on the planet, to survive! Nature did not intend them to be cut weekly so we have to show these plants some respect and cut them in a way that allows them to maintain health and vigour.

During early spring, grass plants put out fleshy, horizontal leaves with which to catch sunlight and through a process known as “photosynthesis”, they convert this sunlight into energy in the form of starch. This is one element that we cannot artificially give to the plants so they need to maintain enough leaf area with which to carry out this process otherwise they will be starved of energy.

As we move into the spring, we should never cut lower than 25mm. At this height, the plants will still be able to produce energy and in conjunction with the correct nutrition, provide you with healthy plants leading to a nice green lawn. As the weather begins to warm up, we should raise the cut height to 30mm which will help provide a little more leaf cover to protect the grass plants against UV light and direct heat. One of our worst failings is that we have a tendency to cut our lawns on weekends and bank holidays very short if it is very hot before we get the bar-b-que out!

Raising the cut height will also help reduce moisture loss and will help maintain the appearance of the lawn by simply providing a thicker layer of green to look at, this is not unlike the effect of having 3 or 4 coats of paint rather than just one.

During early summer, the grass plants will move from vegetative production into reproduction as they try to produce a flower and seed. (this we don’t see as we cut the top of on a regular basis). This in effect means that the plants produce less horizontal leaves as they are putting all their assimilates into one stem, hence sometimes we see less colour in the lawns at this time. Towards the end of summer, the reducing day length will trigger the plants into returning to vegetative production as it is past the time when it should be trying to flower. This is to produce fleshy leaves again to harness as much sunlight as possible to store in the root system to survive over winter.

At this time, the sunlight is diminishing and so we need to make sure that there is enough leaf cover left on the plants to harness enough of the reducing radiation. Therefore we need to be increasing cut height as we move into the autumn so that when we put the mower away for the winter, we have a height of 50mm plus. This extra height also means that we have the protection of the thermal layer when the weather is cold to help protect the plants. We should definitely not be reducing the cut height so that we can use the mower to hoover up leaves! Lawn mowers are for mowing grass and leaf blowers are for collecting leaves!. Cutting the grass lower at this stage is a good recipe for increasing moss levels.

Where sunlight is restricted by buildings, hedges and trees, for the reasons above, we need to increase the cut height significantly throughout the whole growing season to help maintain plant health.