Water – When it comes to the garden, water can be a blessing and a curse. One year brings heavy rain, while the next might bring severe drought challenges. Mother Nature can definitely wreak havoc on our garden success, but there are steps we can and should take to offset those wild swings in moisture levels and be more efficient with watering.
Joe Lamp'l audio
First though, let’s take a look at some important aspects of water that you might not realize. Have you ever read the book The Big Thirst: The Secret Life and Turbulent Future of Water by Charles Fishman? If not, I highly recommend it as a fascinating look into this precious resource.
Let’s start with a notable fact: The amount of water available on Earth is the same now as it was 4.4 billion years ago.
Water doesn’t disappear, and new water can’t be created. It simply changes form and location. We can’t use our planet’s water supply up, yet there has never been a time in history when some area of the planet wasn’t experiencing severe drought. Water shortages result when the supply moves away from where we have traditionally expected to find it.
Water that falls in New York may have gone airborne in the South China Sea. Across the country or across the planet, the movement of water is out of our control – or is it? Through conservation and good management practices, we can have an impact over how much our regional water remains or shifts away.
Our exploding world population plays a big role in regional water availability. The number of people living on this planet grew at an unprecedented level during the past century. In fact, it grew by a factor of four. That alone would cause an impact, however human water consumption has increased by a factor of seven!
Why has consumption increased so significantly? It’s due in part to manufacturing. Our industrialized manufacturing processes use enormous quantities of water, and tragically, they often damage or pollute the very water sources on which they are dependent.
I live in the Atlanta area, which has experienced the fastest growth of any metropolis in the U.S. during the past 30 years. Over 2.5 million souls have moved to Atlanta in recent decades, and yet, all of us are reliant on the same water supplies which met the needs of Atlanta residents in the 1980’s. It’s taken a toll.
A few years ago, Atlanta experienced severe drought, and we were just a handful of days away from running out of water altogether. Imagine – no water for millions of people. Fortunately, the rain came just in time, but it was a close call that required our regional government to take drastic measures and make plans for long-term change.
Another increase in water use is due to, well, our home gardens and landscapes. For example, 40-50% of all water consumption for the state of Florida goes to outdoor irrigation. As weekend warriors, we are a mighty force, and our actions can carry a significant impact – negative or positive – when it comes to water conservation.
Where and when water will re-appear in any region is impossible to predict. I like the way Charles Fishman described it in his book – thinking of conserving water the same way you save for retirement. Does it provide immediate gratification? No, and sometimes, it requires sacrifice. Yet if we ignore the need, there will come a point when it will be too late.
All this is pretty heavy stuff, I realize. The good news, though, is that good water management can be easy, and it can save you time that you can devote to other garden tasks.
Sometimes, gardeners feel that water equals love in the garden when watering our plants is a way we provide our care and love. Unfortunately, it’s really easy to love those plants to death. In spite of our best intentions, more plants die from overwatering than from underwatering.
The root systems of all plants require oxygen 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.
It really is better to let your soil get too dry than to allow it to remain too wet. On the other hand, plants can only withstand dry conditions for so long. The ideal scenario is to find that perfect Goldilocks-balance between too dry and too wet.
A good rule of thumb for proper moisture is to provide one inch of water each week in the absence of rain. Any more than that is a waste of a precious resource.
Set Yourself Up for Success
Although your region may be experiencing unusual weather patterns this year, consider average conditions whenever you add new plants to your landscape. I’ve interviewed gardening experts and celebrated horticulturists from across the continent, and they all build upon one foundational principle: Put the right plant in the right place.
Pay attention to the plant tag. If it indicates that the plant loves shade, don’t place it in a sunny spot. Ignore this basic need, and the plant will require a lot more water to survive. Yet even with lots of extra care – and water – it still won’t thrive.
Know your climate and hardiness zone. Do you live in an area where drought or flooding is a problem? Does the air in your region tend to be dry or humid? Are your summers intensely hot, or are your winters bitterly cold?
These are basic questions, but they can be so easy to overlook when you’re taken in by the beauty of a particular flower or you’re eager to grow your favorite fruit.
We’ve all been there, and it can be fun to experiment. But planting outside of the limitations and challenges of your environment can be expensive, time-consuming – and water wasteful. Stick with plants which are zone appropriate. They will require less water to offset the inevitable struggle which comes as a result of conditions that don’t meet plants’ needs.
The ultimate in right plant in the right place is a native species. Native plants have adapted to withstand heat or cold, drought or flood and other conditions common in your region. They can live and thrive without pampering. Not to mention, they have developed systems to fend off the pests and diseases which are also native to your area.
Your county extension office is a good resource for a list of plants, trees and shrubs native to your area, and there are plenty of spectacular options which have adapted to grow naturally without direct or indirect human intervention.
I’m not saying you need to be a native purist. I’m not – although I love and have mostly natives in the landscape of the GardenFarm™. However, the more native species you incorporate over time, the less supplemental watering will be necessary to keep your garden looking its best.
A Solid Foundation
We can buy all the right plants and put them in all the right locations yet still struggle through an unusual stretch of heavy rain or parching drought. Mother Nature will always keep us on our toes, but a proactive focus on soil health will provide a foundation for your plants to better withstand a weather crisis.
Healthy soil contains lots of organic matter. The particles of those organic materials act like a sponge to hold water, so it can be accessible to plant roots as needed. At the same time, those particles also create better drainage, so an excess of water is able to seep away from roots more quickly.
As you improve your soil with organic amendments, like compost, you’ll achieve that moisture-maintenance sweet spot, which will help your plants weather the storm (or drought).
You can test your soil’s ability to balance moisture by holding a fistful and squeezing. If it binds together in your hand but breaks apart easily when you run your finger through it, you’ve got a good level of organic matter to ensure proper water retention. If your soil is sticky or won’t bind together, amend with more compost or other organic materials.
It will take a little time to achieve the right balance, but no matter what you’re starting with, you can have great soil. It will save you time and resources when it comes to watering, and it will save money in plant replacement too.
Natural mulch is another great way to continue improving soil health. The mulch will break down over time as another good source of organic material. In the meantime, the layer will act as a protective covering over soil to reduce water evaporation from wind and heat. With a 2” layer of mulch in place, you can reduce your watering frequency by several days. That’s a big win-win!
Improving soil health doesn’t just apply to your garden and landscape beds. It will go a long way toward reducing the amount of supplemental water your lawn requires too, as well as its ability to withstand heat and drought.
Lawns don’t have to be water and resource hogs. Thanks to my maintenance techniques, my lawn didn’t require any supplemental water all spring and through the end of a hot June here in Atlanta.
Early every spring, I add a half-inch layer of compost to my lawn as a top dressing. I also feed it with Milorganite twice each year, because the organically-derived nutrients break down slowly to provide an ongoing benefit.
I also aerate – every year. Aeration improves root expansion, water infiltration and availability of oxygen to grassroots. The open space also provides voids for the compost and Milorganite to penetrate more deeply.
Every type of grass has a preferred height range, and when I mow, I always cut at the maximum height. For example, my cool-season fescue is healthiest at a height of 2-3”. By mowing at 3”, I’m leaving tall blades which will shade out weeds and the soil surface. Plus, those taller shoots promote deeper roots.
When it is time to irrigate, remember that roots are opportunistic. They go where the water is. Water remaining near the surface encourages the roots to remain near to the surface too, which doesn’t set them up well for times of drought.
Water for a longer period once or twice each week, so it will be absorbed more deeply into the soil. This encourages the roots to grow more deeply to follow the water. There, the soil remains cooler, and roots are at less risk of drying out.
Watering less often “trains” turf (and plants) to be more resilient during periods of drought, which naturally translates to less frequent watering.
Since watering your lawn means overhead water delivery with some sort of sprinkler system, the absolute best time to irrigate is early in the morning. Heat and wind increase evaporation of water moving through the air. In fact, up to 50% can evaporate during mid-day application. That means less water hits your turf to be taken in by the roots.
Water during nature’s dew cycle, generally between 4:00 and 7:00 am. With less heat and wind in these early morning hours, you will decrease the amount of evaporation and increase the time the water has to absorb into the ground. Plus, grass blades will dry off quickly in the morning sun, which lowers the risk of fungal disease.
The only spot where you do need to water frequently is your container garden. All sides of the container are exposed to heat and wind, so the soil inside dries out much more quickly. A naturally wicking container material, like terra cotta, will only compound that problem.
Containers typically require water once a day (depending on their size), and during the hottest weeks of the year, may even require a twice-daily watering.
Fortunately, you’ve got the ideal tool for checking whether or not you’re providing sufficient water, and it’s attached to your hand. Just stick your finger into the soil, down to about the second knuckle. If your finger comes up dirty, there’s enough moisture. If it comes up dry and relatively clean, the soil is too dry, and it’s time to water.
Don’t overlook the benefit of mulching your containers too. A densely planted container may not need mulch, because the leaves of the plants shade out the soil surface. However, cover any exposed soil with a layer of mulch to really cut down on the amount of water you’ll need to provide.
Next week’s podcast will feature a lot more on the subject of container gardening, including the best type of soil for water retention, so don’t miss that one.
New Trees and Shrubs
Here’s another exception to the “water infrequently” rule: trees and shrubs which aren’t fully established. It takes longer than you might think for something to become self-sufficient after planting – especially if your area is experiencing hot and dry conditions. I have made that mistake myself and have lost 10-15% of the trees & shrubs I’ve planted at the GardenFarm, because I assumed the plant had established. I backed off on frequent watering too soon. The plant died, and I had to start all over again. That’s frustrating – and expensive.
Establishing roots need continued supplemental watering in order to expand outward and sustain top growth until they become self-sufficient. Surprisingly, this can take two years or more, depending on environmental conditions above and below ground.
A well-established tree or shrub will be healthier, more resilient and better-equipped to thrive with less water down the road.
Also, timing really is everything here. Plant your trees and shrubs in fall or early spring – avoid planting during the heat of summer. You will save a lot of water, time and heartbreak simply by planting during the cooler seasons of the year. Fall, in particular, is the ideal time. Air temperatures are cool, but soil is still warm. That’s the ideal environment for root development with less stress and demand on above-ground growth.
The moment immediately after you get that plant in the ground is pivotal. Provide a good soak using a gentle, steady flow. Too much water too quickly can’t be taken up by the roots, so most of it washes away – taking valuable topsoil, compost and/or mulch with it.
Initially, I water newly-planted trees and shrubs every day. I gradually ease off until, by week four, I’m watering about every fourth day. By this time it’s good to allow the soil to dry out somewhat between waterings. Just not for too long. The soil within the drip line (the area of ground within the spread of branches) should be slightly moist but never soggy.
How much water they require and how long overall it will take them to establish depends on a number of factors – heat, size of the rootball at planting time, time of year, etc. Observation is key here. As you back off on watering, keep a close eye on how the plant responds.
It’s common for trees to lose up to half their leaves to transplant stress, but more loss can indicate a potential problem. If you sense the plant is responding poorly, and you are watering consistently; you’re likely overwatering.
There are a number of tools and methods to use when watering your landscape in the absence of rainfall. The right system for each area will reduce the amount of time you need to take to manage water in your garden, and it will reduce the amount of water you use.
For containers or areas where you need precise water delivery; drip irrigation is the ticket. Water is delivered through a solid supply hose from the spigot. Along the supply hose, quarter-inch tubing is attached wherever you need it to direct and deliver water to precise locations by way of plastic drip emitters.
The emitters are plastic tips which control the rate at which the water drips out. They are available in different sizes, depending on your desired flow rate.
This targeted approach pinpoints the quantity of water you choose right where it needs to go – the base of the plants and their roots. Using the least amount of water for the greatest benefit.
Drip irrigation kits and systems are incredibly easy to install. They are inexpensive and readily available at home improvement stores and garden centers. I’ve had great success with using Rain Bird drip irrigation products.
In situations where you need the accuracy and automation of a specific flow rate, but you need to cover a larger area – your best solution is emitter tubing. That’s what I use in my raised beds.
Emitter tubing delivers water through evenly-spaced emitters along the length of the tube and with even pressure from the beginning of the tube to the end. Don’t worry if your plants are spaced more closely together than the emitter intervals. Water moves downward in soil, but it also travels horizontally – through capillary action. So, it will travel along the soil surface between the emitter placements.
That said, soaker hose can be a good option for densely planted areas or rows of plants spaced very closely together, like lettuce. Soaker hoses are porous, allowing the water to seep out slowly along their entire length into the surrounding soil.
All soaker hoses are not created equal. I love to recycle, but I don’t love to use soaker hose made out of recycled tire rubber. Most soaker hose is made that way, but I have concerns with the chemicals from recycled rubber leaching into my soil, especially around my edibles. I prefer to use food-grade, polyurethane hoses.
When I need to give one plant or one small area a really good soak, my favorite option is a bubbler or soaker head attachment. The thick, heavy droplets and gentle flow of a bubbler hose attachment allows the water to saturate deeply and doesn’t wash away the mulch or soil. The attachment lays on the ground, so there is little evaporation.
Home improvement stores and garden centers should all have these bubbler or soaker attachments available for less than $10.
I pair the bubbler with a Quick Shutoff Valve to control the water flow volume. The shutoff valve has a lever you turn to completely shut off the water flowing from the supply, or it can be left partially open to control how much water is flowing from the supply. You have the ultimate control over flow rate.
One of the best aspects of most of these watering methods is automation. As busy gardeners, we all have so many things to accomplish. The ability to automate water delivery can be a lifesaver. Most importantly, automation is waterwise. In controlling the timing and flow of water delivery, we can get it just right – with very little waste of that precious water resource.
So much of my day would be spent in turning my water supplies on and off were it not for portable, battery-operated timers. These small devices cost around $30 and are worth every penny. They allow me to set day, time and duration – automating when the water moves through my drip irrigation, emitter tubing and bubbler. When the time I’ve programmed is up, the water shuts off.
Spring operated timers work nearly as well, as long as you don’t mind setting them manually each time you need to control the watering period.
With programmable timers attached to my irrigation systems, I know that all my raised beds, in-ground beds, containers, etc. are all being watered when I want them to be watered and at the amount I want them to receive. Even if I’m out of town, the watering goes on as scheduled.
Best of all, I’m using water as efficiently as possible, with very little waste.
If there is an area of your landscape which is hard to reach with a hose, drip irrigation bags may be your solution. These leak-proof bladders have tiny holes in the bottom. Place the bag at the base of your plant and fill it with water. During the course of the next 6-12 hours, the water will seep slowly into the soil. There are a number of style options and sizes (number of gallons the bag will hold), so you can find the bag that will best fit your needs. I’ve liked using the Treegator in my landscape.
Getting the Amount Just Right
For all the areas which require an inch of water per week, the best way to measure how much you’re providing is with a tuna can.
Place empty tuna cans in a few spots under your sprinkler, and once there’s an inch of water in the can, you’ll know how long it takes to deliver an inch of water from that sprinkler. Let’s say you prefer to water your lawn twice a week, measure the amount of time it takes to deliver half an inch of water into the cans. That way, you’ll know how long to water twice weekly to provide an inch of water overall.
In areas where you use a soaker hose, bury the tuna can until the rim is right about at soil level directly underneath the hose. Again, you’ll know how long to run the hose by how long it takes for an inch of water to build up in the can.
Just remember – that’s an inch of water in the absence of rain. When your area does receive rainfall, back off by approximately how much moisture you think may have fallen. If you don’t know the precise amount, don’t sweat it. Just remember that it’s better to be conservative and provide less supplemental water than too much.
When rain does come, make the most of it. Harvest it in a rain barrel system.
Did you know that a 2,000 square foot roof in an area where the average yearly rainfall is 20” could harvest up to 24,000 gallons of water? Imagine the difference that makes in the use of a traditional water supply.
The most basic form of rainwater harvesting is simply collecting the water in a rain barrel and distributing it manually to the plants. This method is referred to as a “simple” system – diverting rain from the gutter into a barrel to use on your plants.
A rain barrel won’t save your lawn during a drought, but it will provide a source of water for your vegetable garden or any prized plants, trees or shrubs which would be expensive to replace.
Another good practice is to harvest warmup water from indoors. Every man, woman and child in America uses an average of 100 gallons of water every day. Some of that runs down the drain as we run a faucet until water gets hot, for example. If you place a bucket under the faucet to capture that water instead, it adds up quickly. I did this when Atlanta experienced that severe drought a few years back, and I gathered more water than I needed for all my plants throughout my garden.
At the end of the day, it’s really about being more mindful in how we use and deliver water in our own little corner of the world. Our plants will be healthier, but most importantly, we’ll be making a significant contribution to maintaining how much water remains in our region for future needs.
If you haven’t listened in to this recording, you can click the Play icon in the green bar under the title at the top of this page. I hope all of these tips and reminders will reinforce your efforts at being waterwise. Less really is more when it comes to water in the garden.
By Joe Lamp'l July 11, 2019
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