Most gardeners have relied on the rule of thumb that the garden needs an inch of water per week to stay healthy, but the fact is that a plant needs different levels of water at different stages of growth and in different environmental conditions, such as weather and humidity.
Why is watering correctly so important for plant health?
Water is required for a plant’s metabolism and cell expansion by bringing nutrients from the roots and distributing them throughout the plant’s vascular system.
Water is necessary for propagation to allow the seeds to germinate. Even if you propagate through leaf cuttings or air layering, water is needed for the process.
Water provides the stiffness of the herbaceous parts of the plant (turgidity), which allows plants to stand up straight and leaves not to wilt.
Photosynthesis is the fuel for plants to thrive. Water + CO2 + sunlight + chlorophyll combine to form sugar and oxygen, which are essential to plant health.
During photosynthesis, plants release moisture through the pores of the underside of their leaves (transpiration). This continuous cycle of absorbing water through the soil and then releasing it into the atmosphere can be affected by variations of the air around the plant.
If the weather is dry, windy or hot, more moisture gets released. If it is cool, cloudy or humid, less moisture is released.
New plantings need the best watering techniques to get them settled in and started well. A good root system requires water to grow and must be established to ensure shoots above the soil will have the best chance to thrive. Plants established for a year or two may be able to withstand less watering if their root system is healthy.
Adding organic matter aids the soil’s ability to hold water, helping the water cling to soil particles, much like a sponge.
Mulch creates air pockets for water to remain longer before draining away, leaving more time for the roots to absorb. The more moisture-holding ability a soil has, the longer your plant can go between watering.
Can you rely on Mother Nature to do the watering for you? She might need your help. If rain has fallen, check your rain gauge to determine how much moisture arrived.
If your plant is in a sheltered spot where rain does not penetrate, planted where competition from surrounding plants might affect it, or has large leaves that may disburse the water away from the roots, test for soil moisture to make sure the roots have been well watered. If not, get out the watering can.
How can you tell if your plant needs water? Although soil moisture testers can be used, your finger works just as well.
Place a spade into the soil and push back several inches to see how it looks and feels. If the hole is dry, water deeply and thoroughly at the root level, not on the leaves themselves, which may encourage fungal disease. Watering in the…