One question that I probably get asked the most is “how much do I water?”. That’s really a loaded question. With out being in your garden, no one can tell you how much to water your garden, or flower bed needs. Each garden has its own idiosyncrasies that must be observed. My water needs in my garden has changed over the years. I have built the soil up with organic matter and I have literally changed the structure of the soil. From clay to good draining soil. Plants need water to absorb nutrients in dissolved form starting at the roots. If the plant is deprived of water the cells in the plant start to shrink from the tips down, burning the ends and making the plant stressed and more likely to be unhealthy. Adequate water is essential for the plants survival.
Get to know your soil. Dig into your soil to find out what kind of soil you have. It makes a big difference in your drainage. Clay-layden soil has special watering challenges. In dense clay , little room exists for air to pass through and reach the roots. Clay drains very slowly and compacts easily. This is the type of soil I have. It took many years of adding soil amendments to get proper drainage. I think it’s the hardest soil to work with. When the surface seems dry, you could be drowning the roots below, so you should always stick a finger in the soil to test for moisture. Sandy soil has other challenges. Although the drainage is very good, you may have to water 4 times as much as someone with clay soil. Because of the quick drainage, nutrients are lost quick too. Both clay and sandy soils can be turned into a loam by mixing in loads of organic material, such as compost.
Keep water percolating in the zone. The plants roots systems are the most critical area of watering. The depth varies among plants. In general, we are talking about the first 6 to 8 inches of the soil with vegetable gardening. Keeping that section moist prevents the plants from becoming parched by thirst or stressed from binge drinking (giving them lots of water and letting them dry out). With good garden soil, you should be able to squeeze a little dirt into a clump that will break up easily if you gently bounce it in your hand.
Mulch your garden to conserve water in your soil by shielding the ground from the hot sun rays that burn off moisture. Thick layers of mulch also helps keep weeds at bay which also rob your plants from moisture and nutrients.
Recent transplants need frequent, light watering to accommodate for their shallow roots and ease the shock of being pulled from their pots. Newly sowed seeds need a light sprinkle often to keep them moist so they can germinate. Steady watering is also critical at the time of flowering and fruit formation. For some crops, like tomatoes, yields may improve, but some flavor may be lost with too much watering as fruit ripens. With carrots and cabbages, for example, watering should be reduced as the crop reaches maturity to keep the vegetables from splitting. Once plants are established, more harm than good is done by giving them a daily sprinkling. We want plant roots to go deep once they are more established. Water deeply, less frequently and the roots will go down searching for water rather than looking up to the surface for water which will cause them to dry out faster.
Early morning, and evening are usually the best times for watering because the cooler the temperatures, the less evaporation. These times are particularly good when using an overhead sprinkler. Under bright sunshine, water droplets intensify the rays and can singe the leaves. I like to give my plants an overhead sprinkle every once in a while to “wash” the dust off early morning, even though I use drip tape in my garden for my main watering. Night time is also not the best time to water with a sprinkler because the leaves stay wet and that can encourage disease. However, like my area being so arid I will turn my drip on overnight at a very slow rate to water deeply and there is little evaporation that way.
Group your plants in the garden with plants that require the same water needs. For example, lettuce needs plenty of water and many herbs are drought tolerant. It really wouldn’t make sense to intermingle them together. By grouping plants with the same water needs you won’t be wasting water.
Watering pots is a whole other creature. Pots don’t have large amounts of soil surrounding them to help keep them moist. They are above ground and heat up quicker during warm days. And they have better drainage. During the spring months when the pots are newly planted the roots haven’t taken up a large amount of pot space, they don’t require as much water as they will later when the roots have grown into a mass. Usually once a day is enough. But come summer months, depending on the size of the pots I find that I need to water them twice a day. Watch them closely to see what they require. One hot day can completely wipe out some of your back porch beauties if you skip a watering
According the a common rule of thumb, a garden needs about 1 inch of water per week. Now this can be tricky! You have to use common sense here. If you have had winds, your soil will dry out quicker and it may require water more often. If you have had rain……..Turn off the water. If your soil is sandy and it drains faster than you can say “rain”, more than and inch a week might be necessary. The temperatures will affect the amounts of water you need. We can reach 110 degrees here in Southern Utah for weeks at a time and the plants will look wilted and yet they were just water earlier in the morning and the ground it’s still wet. Plants may do this to protect themselves by exposing less surface to the sun and conserving water. But of course, if the soil is dry, you better give it a drink so it can survive the day!
Be water wise!