How Much Water?
Ideally, garden soil has about 45% minerals, 5% organic matter, 25% air and 25% water. That generally means about 1” of water per week (Georgia averages about 50” of rainfall per year). Water is essential for the healthy functioning of plants, just as it is for our bodies. But, when there is too much water in the soil, your plants can’t get enough oxygen.
Water & Soil
You could think of healthy soil as being like a sponge. It absorbs and retains water. Soil with 25% water content is like a sponge that has been soaked and squeezed so the excess moisture has been removed. If you squeezed hard about one drop would come out.
Sometimes soil can “lose its structure.” That means that it can no longer absorb and retain water, we will discuss this further in the Soil Notes. This condition makes watering a challenge because it means that water is not available to the plants. So, soil structure is an important part of watering.
Mulching is also very important. Mulched soil loses much less water (~25% less) to evaporation than soil that is exposed to the elements (not a good idea). Again, we will discuss mulch further in Soil Notes.
When to Water?
Watering in the morning seems to best for plant health. During the afternoon there will be much more water lost through evaporation, and any water that gets on the leaves can cause them to burn.
Established plants need to be watered deeply and on a regular basis, maybe three times a week. You could measure how long it takes to spray 1/3” (1”per week/3) (~3 seconds or a 3 count) of water into a bucket. That could serve as a gauge for watering an area about the diameter of the bucket. And, you can always check the moisture level with your finger extended about 2” into the soil, or with a water meter. By placing a rain gauge in your garden, you can get an idea of how much rain has fallen during the week and adjust your watering accordingly (if 1/2″ has fallen, only watering an additional 1/2″).
Planted seeds need to be kept moist during the germination phase. You might water them once or twice a day (~1 second). Once the plants have developed some roots they could be watered about three times a week. Again, this depends upon the temperature, amount of sun, and how much rain has fallen during the week.
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Watering Methods
In order to avoid problems with fugus and leaf burn, it is best to direct your watering to the ground, not the leaves of the plant. Like everything in the plant world, there are exceptions to this, but it is a good rule of thumb.
Watering by hand with a watering can or hose are some of the most common ways of watering a garden. Using a watering can is less convenient, but it does allow you to dip into a rainwater barrel if you have one. You could time your watering as described above.
Using a water irrigation system allows for more precise and timely distribution of water to your garden. These do not need to be complicated or expensive. Here is one that can water four 25’ garden beds for under $30, and another simple installation with a timer is shown in this video.
Water Quality & Water Collection
…JMS, Comfrey Tea & tray watering
During this time when one of our main sources of fertilizer, urea has so dramatically risen in price, it is worth having some awareness of the similar benefits of urine– you can read and decide for yourself.
