Six Ways to Water Your Garden & Landscape

1. Automatic Sprinkler System 
2. Hose with Garden Sprayer & Sprinkler
3. Soaker Hoses
4. Drip Irrigation
5. Ollas
6. Water Harvesting

So what’s the best way?

I use almost all of them. My front lawn is on an automatic sprinkler system. The garden beds are on a drip system (in the More Water Zone), and our cane fruits, tree fruits and containers, are also on the drip system (in the Less Water Zone). The container plants get tied into the Less Water Zone of the drip system. All other potted plants are hand watered. And when the temps soar into 100+ degrees, I feel sorry for my natives and hand water them. (Poor ferns!) The back lawn gets a round sprinkler attached to the hose during long dry spells to prevent the grass from fully dying during its dormant period. I haven’t had the privilege to try an Olla yet. But I do have a rain barrel that I use to water starts and the front yard, and a rain chain collects roof water and runs to our blueberry patch via a rock lined conveyance trench.

How Much Water Does My Lawn and Garden Need?

Just the right amount. Too little and your tender transplants and seedlings will experience drought stress. Too much and your plants may succumb to one of these over-watering hazards:

• Saturated soil inhibits gas exchange at the root zone (i.e. drowning).
• Washes away nutrients.
• Chills the soil.
• Encourages slug activity.
• Encourages crown rot in susceptible plants—I’m looking at you raspberries and asparagus.

OK, I feel you wanting to throw up your hands. It’s easy and simple, once you get going. You can dial your system in using the GCR method: Guess, Check, Refine and get pretty good results.

For those more comfortable with metrics, check out Regional Water Providers Consortium and plug your zip code into their Weekly Watering Number and using weather data they will be able to give you a figure for how much water will be needed to keep your lawn and garden healthy for the week. During our dry period, mid-June through mid-September, it normally takes about one inch of water per week to keep your lawn healthy. Then ¾” or 75% for your vegetable garden and ½” or 50% for your perennial and shrubs. 

I use the WWN as a general guide and starting point then adjust by feel, looking at the temperatures, conditions of my plants, and peeking down in the soil occasionally. 

If you are a metrics person, get the WWN and spread that out over the week.

Find out how long you need to run your system to get 1” of water.

1. Put out a plastic tub or tuna can and turn on the system. 
2. Time how long it takes to fill to a ½”, or the full 1 inch if you hate math. 
3. Write the flow rate down. Yes—write it down. No, you won’t remember.
4. Program your system accordingly. I like to water twice a week in the cool part of spring and summer. Then adjust to three days a week in the heat of summer. 
5. Adjust as needed according to the WWN.
6. Monitor your soil to make sure the water is getting down to the rhizosphere, but also not over saturating.  

It doesn’t have to be perfect, but this will get you in the ballpark and prevent you from watering your lawn so much it runs into the cul-de-sac sending expensive lawn chemicals down the storm drain. 

Irrigation Controllers: If you like to travel in the summer like I do, an irrigation controller can give you peace of mind. Some smart controllers will automatically adjust to the WWN or allow you to manipulate through your smart phone.

If you hand water, place a graduated cylinder in the area and sweep water back and forth as evenly as possible until it’s at the desired mark, ⅓” for example. You can leave your cylinder out or time yourself to see how long it takes. I also like to use a trowel to take a peek to make sure the water is reaching the roots.

When to Water 

Morning, morning, morning. I used to scoff and water whenever I felt like it, but experience has taught me the reasons for morning watering. 

• Water chills the soil. Watering when it is already cool lets the sun continually warm it throughout the day.
• Dry surfaces at night discourage slug activity. Slugs are most active in the evening and night. If you water in the afternoon, and your soil and foliage is damp in the evening, you are inviting slugs over for dinner party and laying out a wet carpet for their convenience. 
• Funguses also love cool, moist conditions. So putting your garden to bed moist creates conditions funguses need to thrive and spread.

Drip Irrigation

This is the gold standard irrigation system for gardens. The lines and emitters are infinitely customizable to your garden and the system retains pressure for exceptionally long distances. In fact, too much pressure is the usual problem. (Fixed by a pressure reducer at the water source.)  

Why drip systems are awesome:

• Delivers water slowly to plant roots. Allowing them to uptake the water as it continues to emit.
• Foliage stays dry.
• Creates a small wet mark on the surface of the soil, while most of the water balloons out sub-surface at the rhizosphere. Take that moisture loving slugs. 
• Very little water is lost by surface evaporation. 
• Parts are affordable.
• Infinitely customizable.
• Like playing with tinker toys.
• Tying it into your irrigation controller (or installing one) can ensure your garden gets reliable water at 4am. Whereas I am not reliable at 4 am. 

Downsides: 

• It requires some upfront learning, design, and planning. I found youTube and irrigation company websites very helpful. (DripWorks, Hunter, Ewing, Rainbird) 
• Math: I needed to calculate how much tubing, elbows, figure 8s, end plugs, etc. UG!
• The tubing gets in the way at times. 

Once your system is installed, test the flow rate by turning it on with a small tub in place to measure how long it takes to get to that 1” mark. Then program your system accordingly to deliver the desired amount of water to each zone. 

Soaker Hoses

These have the advantage of emitting water slower and keeping the foliage dry. However they don’t hold pressure well making it difficult to string them together over long distances. The plants and beds nearest to the water source get the most water and less farther away. 

Hose & Sprinklers

Even the most experienced gardeners tend to overwater when watering by hand. I tended to under-water because I am impatient. Watering by hand also takes the most of your time, is easy to forget, and gets the foliage wet which can promote some fungal problems.  People do it, but this is the most problematic method. 

1. It takes a long time. It took about an hour for me to do an inadequate job. When we would leave for vacation, our friend’s eyes would pop out when we gave them the watering tour. 
2. A lot of the water is lost to evaporation.
3. Slugs and fungal diseases love the wet, humid environment broadcast watering creates.

Ollas

These are unglazed clay jugs that you bury in your garden soil, leaving the neck exposed with a cap. Fill with water and walk away letting capillary action draw water from the pot as needed. Or better yet, tie them together via a drip line. No surface water to attract slugs, almost none lost to evaporation, and less chilling. I am romanced by the idea of ollas.

Photos provided with permission from Dripping Spring Ollas. Watch this video to learn more about how they work.

Water Harvesting

Water harvesting is a wonderful way to water your garden. The only problem is that our normal 50 gallon barrels are inadequate. However, there are many creative examples of allowing barrels to overflow to a channel that is directed to a garden or rain garden space. We have a rain chain that irrigates our blueberries May – October and a 50 gallon rain barrel that I use for our front yard garden space. You can also hire companies like Oregon Rain Harvesting to design and implement a water harvesting system to meet your needs. They can even plumb your house with rainwater!

Best Practices for Watering your Gardens and Lawns

1. Water early in the AM.
   • The ground is already cool so you won’t be inhibiting soil warming throughout the day.
   • Less water is lost to evaporation.
   • Discourages slugs by minimizing the amount of time the top layer of soil is wet. Water just before the sun comes up to let it soak in before the sun dries the top layer. Evening watering means it will stay moist until morning. This creates a mollusk night club for slugs to party in–all night long. Munch, munch, munch! 
2. Rather than a short daily watering, try to water every other day or less using the WWN. Remember it’s generally 1” of water over the week. This might take some fine tuning, but once you get it dialed in your garden and your wallet will thank you. 
3. Check on your beds throughout the day and watch for drought stress. Dig down and check that water is reaching the root zone. I find the WWN to be a little lean at times. 
4. Lawns: aerate your lawn every spring to help water infiltrate to the root zone before running off. Without aerating you might find that your water runs off but the soil is dry ¼” under the grass. 

Resources

• Regional Water Providers Consortium – Weekly Watering Number
• Book: Gardening with less Water, By David A. Bain Bridge
• 7 Basic Steps for Creating Water Efficient Landscapes (.pdf)
• TWSCD: Seven Steps to Create a Water-Wise Landscape
• DripWorks: GardenGirl Installs Drip Irrigation With Dripworks (From hose bib)
• Rainbird: Rain Bird Pop-up Sprinkler to Drip Conversion
• Ewing Irrigation: How To install A Drip Irrigation System (New manifold, new controller, underground mainline.)
• Ollas Video Automatic Irrigation with Dripping Springs Ollas
• Dripping Springs Ollas