There are a number of growth factors that have an affect on the overall growth and development of your plant, including the amount of water they receive and the nutrients available for growth. Water is essential for all forms of life, including plants. Plants use water and carbon dioxide to make sugars through the process of photosynthesis; however, gardeners occasionally supplement this natural process with additional sugar to help bolster a lackluster plant.
Water is introduced to plant tissues via the root system. The roots draw the water from the soil and pull water molecules into the interior of the plant through a network known as xylem vessels. The xylem vessels function as the plant's circulatory system, carrying water into and throughout the plant; from the roots to the leaves and stem. Water carries nutrients the plant needs for proper growth throughout the tissue, ensuring proper distribution of the essentials. Plants also use water during photosynthesis, which is the process by which plants make food from sunlight. Additionally, water helps the plant stay within a healthy temperature range, evaporating as the surrounding temperature heats up.
When plants convert light energy into food via the process of photosynthesis, the end product is stored within the plant as sugar. Generally speaking, plants use naturally occurring carbon dioxide as their primary source of carbon, and it is therefore unnecessary to add additional carbon in the form of table sugar. However, for young plants or those who seem to be struggling to thrive, the addition of table sugar to their water can help to bolster lackluster growth and development. However, too much sucrose can damage the plant rather than help it. This is because adding sugar to the water changes the water's composition. Water moves into the roots of the plant by crossing a membrane through a process known as osmosis. When you add sugar, you change the osmotic potential of the water, and less fluid is taken in by the roots. On the plus side, the surrounding soil will retain its moisture longer, and the presence of sugar will attract pollinating insects to your garden.
To add sugar water to plants, combine 1 tsp. of granulated sugar and 2 cups of hot water. Stir until the sugar is completely dissolved, and then set the mixture aside and allow it to cool completely. Once the mixture has reached room temperature, pour the solution slowly around the base of the plant, completely saturating the surrounding soil. Repeat this process three times a week until you begin to see healthy plant growth.
Once a plant has all it needs in terms of water and nutrients, it will grow in one of two ways. Plant cells will either expand or divide. When plant cells expand, they begin by taking in extra water. The water causes the cell to swell, creating pressure against the rigid cell walls. This pressure pushes the cell, causing it to soften. This allows the cell to elongate. Once a cell reaches a pre-determined maximum length, the addition of secondary wall thickenings prevent further enlargement. The second way plants grow is through cell division. In this process, new cells are formed by the division of cells already in the plant body. Each time a cell undergoes the division process, two new cells are formed. When water is restricted, cells cannot properly grow. They take in what water is available and expand until the cell wall can no longer enlarge and growth stops. The result is a spindly plant with small fruits and leaves, weak stems and reduced root growth.
In addition to water added manually to plants, growth is also affected by moisture in the air or relative humidity. This is because the relative humidity directly impacts the rate of plant transpiration. Transpiration is the process by which plants lose water vapor, primarily through the leaves. Higher relative humidity results in a lower transpirational pull.This is because there is less difference in the water content between the interior of the leaves, which are saturated, and the external air.