Grasses contain chlorophyll, which gives plants their green color. Chlorophyll enables the process of photosynthesis by which a plant produces the food material (carbohydrates) it needs to function using energy from sunlight, carbon dioxide from the air and water from the soil.
This equation shows the photosynthesis process: 6CO2 + 6H2O + light energy = C6H12O6 + 6O2 The oxygen that is produced as a byproduct of this reaction (6O2) is released into the air.
Through the process of respiration, plants convert the energy stored in the carbohydrates photosynthesis produces to the energy they require for their growth processes.
Grasses are part of the monocotyledon plant group, also referred to as monocots. They are flowering plants that have one seed leaf (or cotyledon) in their seed. This differs from the dicotyledonous plants (dicots) that have two leaves in their seed.
Grasses can be identified from other monocots in that each successive leaf of a grass is attached at a 180 degree angle from the previous leaf. The large, diverse group of grasses includes more than 10,000 individual species.
What distinguishes turfgrass plants among this group is their ability to form a high density under the continuous defoliation that occurs during mowing. Fewer than 50 of the grass species fit into the turfgrass category.
When growing conditions are favorable, turfgrass can produce the carbohydrates it requires for immediate use and store the excess for later use. Environmental conditions, and the management practices you use in maintaining your lawn, combine to affect the turfgrass plant’s production and storage of carbohydrates.
High temperatures increase the respiration process so more carbohydrates are used. When temperatures become very high for an extended period, the turfgrass plant may use so much of its carbohydrate supply that too little remains for growth and the plant goes dormant.
The mowing height you use affects how much green tissue (containing chlorophyll) the turfgrass plant has available for the photosynthesis process. When the mowing height is higher, more carbohydrates are produced. If you mow at a lower height, especially during high temperatures, you reduce the green tissue of the plant. This limits carbohydrate production and can stress the turfgrass.
Your fertilization program makes an impact, too. High nitrogen applications increase the turfgrass plant’s growth rate, channeling more carbohydrates to production of the green tissue (turfgrass blades) and less to storage.
When your total maintenance program supports the balance between carbohydrate use and storage, your lawn can support more use with less stress.