There’s more to being wise with water than efficient garden watering. I often mention that more plants die from overwatering than from underwatering. That’s the main reason I speak so often about making sure you have well-drained soil.
In earlier parts of this 5-part series; I’ve covered selecting the right plants, water delivery methods, and watering frequency. This time around, I want to dive a little deeper on that frequency issue and help you get a better handle on why frequency matters and some key tips to get it right. Plus, let’s explore making the most of nature’s own water delivery system – rain.
A Little Basic Plant Science
It is actually better to let your soil get too dry than to allow it to remain too wet. On the other hand, you don’t want the water to drain so quickly that it flows right past the roots. The ideal scenario is to find that perfect Goldilocks-balance between too dry and too wet. This can be challenging at times, but observation is your best tool.
The root systems of all plants require oxygen in order to remain healthy. Proper soil drainage and moisture balance allows oxygen molecules to reach plant roots. If soil becomes too soggy, the oxygen is pushed out and the plants literally suffocate and drown.
On the other hand, plants transpire moisture from their foliage in much the same way as we humans expel carbon dioxide when we breathe. This is one of the reasons leaves turn brown when a plant is thirsty. In dry air and times of drought, for example, a plant’s transpiration rate increases. It “breathes” more moisture into the air, and so, it requires more moisture in replacement.
Unfortunately, the symptoms that your plant isn’t getting enough water can sometimes be the same as if your plant is getting too much water – limp and dull leaves, for example. Some differences to watch for:
- Limp foliage that feels dry and is green, or trending to brown, needs water.
- Foliage that is limp and green, tending to yellow, but doesn’t feel dry or crispy is likely a case of overly-wet soil.
For those times when you are unsure, fear not; there’s a simple way for you to know which extreme you are dealing with.
It’s called the finger test. You stick your finger into the soil, down to about the second knuckle. If your finger comes up dirty, there’s enough water in the soil. However if it comes up dry and relatively clean, the soil is too dry, and it’s time to water. Simple, right? (If the soil is too dense to stick your finger in it at all? To you I say: Compost, compost, compost).
Identifying and using a horticultural canary within your garden is another great method to determine when you may not be watering appropriately. Periodically, allow your garden bed to go without water. Observe the bed every day until you notice the first plant within the group to show signs of wilting. This plant becomes your canary. As you spend time in your garden throughout the season, and you notice the “canary” is drooping; you know it’s time to adjust the water level of the entire bed.
As you observe what your plants and trees are telling you, you will only get better at recognizing those subtle (and sometimes not-so-subtle) clues.
Hold On to the Water Mother Nature Provides
Rainwater harvesting is not new. It’s been used around the world for thousands of years, but it is certainly experiencing a surge in popularity within the urban landscape. Did you know that a 2,000 square foot roof area can provide approximately 1,200 gallons of water during a one inch rainfall? The amount of water harvested also depends not just on size but also the surface texture and slope. If the average yearly rainfall of your area is 20”, you could harvest up to 24,000 gallons of water from your roof each year.
Imagine the difference that makes in the use of traditional water supply. Rainwater is a great source for providing supplemental irrigation to your landscape. Free of salts and minerals which can harm plants and root growth, rainwater is the purest irrigation resource.
The most basic form of rainwater harvesting is simply collecting the water in a rain barrel and distributing it immediately to the plants. This method is referred to as a “simple” system. There’s lots of information available for building a rain barrel system, but the basic setup involves placing the barrel alongside your gutter. Rain is diverted from the gutter into the barrel.
You can easily save a lot of money by making your own rain barrel or taking advantage of discounted programs commonly offered through local municipalities. Food grade barrels are readily available from beverage companies and food distributors for $5-20. These are ideal for harvesting and storing rainwater. Install a spigot on the barrel, and you have a ready-to-use rain barrel that will serve your gardening irrigation needs for years to come.
Another common harvest method is a cistern, also known as a “complex” system. Don’t let the name deter you. “Complex” simply refers to the storing of water after it is collected and providing a way to distribute the water later.
Cisterns are available in all sizes and can be installed above or below ground. There are advantages and disadvantages to both, and the cost of installation varies significantly too. If your property is subject to neighborhood covenants, you will want to be sure to check those before moving forward with a cistern installation.
Whichever method you choose, do some research. There are too many details to cover in-depth here, but you will need to bear in mind things such as keeping your system free of debris, overflow concerns, mosquito prevention, etc.
Once harvested, rainwater can be transported to your garden beds through a below-ground system. An electric pump connected to a pipe or a garden hose can carry it to a spigot. If you utilize a gravity-fed system, the flow will vary greatly. To optimize the flow rate or pressure – especially if using a drip irrigation or soaker hose system – you will need to use a pump for better consistency.
No matter the system you set up in your garden, harvesting rain water can really make a difference in the amount of water you use overall.