Watering plants – Do it right.

Along with sunlight and soil, water is essential to the success of your garden. For a healthy garden, you must make sure the plants are getting enough water without overdoing it and flooding the soil. To make matters more complicated, different plants, different climates, and different weather require different amounts of water. People get confused about watering plants when they compare them to a machine like object planted in the soil and they begin using watering schedules. Schedules, like once a day or twice a week, do not work. If you want to learn how to water your garden or house plants correctly you need to learn a little bit about plants and soil.

There’s more to watering your garden than just turning on the faucet. Plant tissues are composed mostly of water and it is water that gives non-woody plants their rigidity. Water is taken up through the roots of the plant and it is lost through evaporation from their leaves. Nutrients travel throughout a plant via water. In the midday heat of summer, plants can lose water faster than they can absorb it from the ground. This can cause afternoon drooping. They will recover when the sun goes down as long as they have enough available moisture.

When water is added to soil, it fills the little holes in the soil and stays there until one of three things happen. Either it runs away, plant roots suck it up, or it evaporates. When too much evaporates, the soil becomes too dry and roots can no longer find water to absorb. The key to understand watering is to understand evaporation. The rate of evaporation is a term used to describe how quickly water evaporates. Many parameters affect the rate of evaporation.

1. Temperature – evaporation is higher at higher temperatures.
2. Type of soil – clay holds lots of water, sand holds very little and peat moss is somewhere in the middle.
3. Size of pot – large pots tend to be deeper and deeper soil holds water better since evaporation takes place at the surface of the soil.
4. Type of pot – clay pots are porous and have higher rates of evaporation than plastic pots.
5. Humidity – evaporation is slower in humid environments than dry environments.
6. Mulch – mulch on the soil surface reduces evaporation significantly.
7. Wind – wind increases the evaporation rate.

Watering schedules

There is no fixed schedule for watering plants as is practiced commonly. For optimum effect watering should be done in the morning and the following have to be considered:

1. Plant type and size
2. Soil type
3. Temperature
4. Weather conditions: Full sun, Cloudy, Rain
5. Container size
6. Planting density for bed gardens and grounded plants

How much watering is needed?

Pots should be watered until all of the soil is wet. This usually means water will be running out the bottom of the pot. For gardens, water until the soil is wet 6 inches below the surface. If it is not wet or at least moist at a depth of 6 inches you did not water enough. Watering properly takes a lot of time and water. It is far better to water less frequently and go deep, than to water frequently. Deep watering is important because it encourages plants to produce deeper root systems. Deeper roots mean that they can withstand drought better and therefore need to be watered less often. Plants in containers need watering more often than plants in the ground. Hanging baskets require the most frequent watering of all. Summer temperatures mean you’ll be watering daily. When temperatures exceed 38 degrees, it’s time to go into survival mode. You’ll need to water at least twice a day. When temperatures are this hot, your garden is under tremendous stress. Don’t worry about keeping the leaves dry. The most important thing is keeping your plants alive.

Best Practices for Watering Plants
Water where the roots are. They need the water.
Water slowly. Let in soak in
Try to avoid overhead watering. Wet leaves invite disease
Water in the morning for best efficiency
Don’t water faster than the ground can absorb. Move on and come back.
Don’t over water and cause water logging. Especially new plants
Don’t let them go dry. Plants get stressed
Use mulch to conserve moisture
Use water saving irrigation methods such as drip irrigation

Adding organic matter
If there’s only one thing you do for your garden this is it. Adding organic matter to your soil acts as a soil conditioner. It improves the structure of the soil, adds nutrients and helps to retain moisture. Organic matter is compost or manure. It should be rotted compost from your compost bin. You know if it’s well-rotted as it has no smell and has a lovely crumbly texture. It will repay you over and over again.

Drip Irrigation

Drip irrigation consists of pressurized tubing that emits a precise volume of water over its entire length. These can easily be connected to timers and water waste is minimized. Drip irrigation systems can be customized to fit any garden type – containers, raised beds, hanging baskets, anything at all.

Credits for information:
Robert Pavlis
Rachel and Ivan Minnis