Roots VS. Shoots
Caring properly for your lawn and landscape requires an understanding of the complex relationship between roots; the below ground support and nutrient acquiring portion and shoots; the above ground foliage portion. Both play a crucial role in plant development and success: roots obtain water and mineral nutrients from the soil while shoots conduct photosynthesis (conversion atmospheric carbon to carbohydrates using energy absorbed from the sun). Roots are entirely reliant on shoots for an adequate supply of carbohydrates (food) to support their normal functions, and shoots are completely depending on roots for water and nutrient supply.
The root:shoot ratio quantifies the amount of shoot matter present in proportion to the corresponding extent of root mass. Maintaining a viable ratio will significantly effective in achieving turf and landscape management goals. Mowing height plays a big part in management of the delicate root/shoot relationship. Because significant amounts of leaf tissue are regularly removed during mowing efficient photosynthetic functioning is especially crucial in managed grasses as compared to other plants. The photosynthetic capacity of grass is dictated by the size of remaining leaf blades and is directly proportional to the amount of root mass and depth that can be maintained for the long run. So, lower mowing heights translate to less leaf area in which to collect sunlight and make food which ultimately means a shallower and less extensive root system. This is the primary reason for the recommendation to mow at higher blade heights as appropriate for species present and turf use.
The next aspect of turf management affecting the root:shoot relationship is fertility. Turfgrasses are most responsive to amounts of nitrogen in soil as compared to other vital mineral nutrients. Tillering; when plants put forth new shoots from the root or around the bottom of the original stalk and density of turf grass will increase nitrogen levels to an optimal point. But beyond that point, shoots can increasingly monopolize valuable carbohydrates which are used to fuel excessive shoot growth that occurs at the expense of root growth. Additionally, root-inhibiting thatch can accumulate very quickly in a high nitrogen environment. For these reasons it is important to apply the proper products at the correct times to ensure a healthy lawn with balanced, adequate nutrient amounts. Your lawn program has been developed with your lawn and landscape needs in mind and should be adhered to as weather and allows.
While many aspects affecting root and shoot health and growth can be managed with cultural practices, environmental stressors can be considerably harder to manage for and mitigate. Heat and drought are the most common stress factors on turfgrass. High soil temperatures may cause extensive root dieback, and lost tissue is not easily or quickly replaced because of generally unfavorable conditions and the fact that the plant must devote a substantial share of resources to stress resistance. Once the root system has been compromised by heat it will be less able to manage water use demands. Careful monitoring of temperature and precipitation will assist in the development of a proper irrigation regime, frequency of water must increase to prevent moisture stress which can eventually force your lawn into premature dormancy due to drought. Creating a strong root system prior to the advent of summer stress is the best combat against root dieback.
