Smart Irrigation

Spray Versus Drip Irrigation: Which is Best for You?

The best type of irrigation system for your landscape can depend on many factors, including the size and shape of your landscape and types of plants you have. Photo: California Department of Water Resources

The best type of irrigation system for your landscape can depend on many factors, including the size and shape of your landscape and types of plants you have. Photo: California Department of Water Resources

Spray irrigation emits water in an overlapping pattern, while drip irrigation delivers water directly to the roots of plants. How do you decide which meets the needs of your landscaping?

The case for spray irrigation

Spray irrigation can be an efficient way to irrigate large landscapes with groundcover or uniform plant materials like lawns or meadows.

Spray systems apply water in gallons per minute (GPM), so if you know the application rate of each spray head, the distance between the heads, and the pressure of your system, it is relatively easy to figure out how much water is applied every time you run your irrigation.

Low volume spray heads apply water at about one-third the rate of conventional spray heads. Newer spray irrigation heads have improved spray with heavier droplets more resistant to wind. Landscaping with grade changes using spray heads should have check valves installed to prevent water flowing out of the lower point heads.

Challenges of spray irrigation include narrow areas surrounded by hardscape, or irregular patterns. Irregular patterns are particularly challenging, because spray irrigation requires head-to-head coverage to be efficient. Odd-shaped areas may be under or over watered. High-volume spray heads that emit water at a much higher rate than soil can absorb should be replaced.

The case for drip irrigation

Drip systems apply water in gallons per hour (GPH), so they often need to run for longer periods of time than spray systems. But the actual run time must always account for precipitation rate and runoff.

Installing subsurface systems (under at least two inches of mulch) is the most efficient way to irrigate nearly every type of garden area. Since the tubing is flexible, it can accommodate a variety of irregular shaped areas or rectangular areas when laid in a grid pattern, and in rings you can easily expand as trees or shrubs grow.

Challenges of drip irrigation include application of water too quickly for your soil to absorb. This needs to be considered when dripline grids are installed. Drip irrigation operates the most efficiently at low pressure (between 15 and 30 PSI). To achieve optimal performance, pressure regulation either at the valve or at the point of connection of the dripline to the buried lateral lines must be used. It is also essential to install some type of filtering system to keep the emitters from getting clogged.

This article was inspired by the 71-page Sustainable Landscapes Program guidebook available at The Water Authority and its partners also offer other great resources for landscaping upgrades, including free WaterSmart classes at

written by San Diego County Water Authority San Diego County Water Authority Logo Stacked Tagline

Let your garden grow with our smart garden buying guide

by Tyler Lizen /CNET

Nature and technology don’t have to exist at odds with each other. In fact, similar smart home tech that automates your thermostat or your garage door can extend outside the walls of your house, helping you make your own corner of nature thrive.

Smart garden and lawn care tech encompasses plant sensors, weather monitors, sprinkler systems and even robot lawn mowers. The diversity is fitting for the great outdoors, but it can also make it difficult to know where to start. Once you understand your options, you can stem your plant killing ways with push notifications, you can save time with automation, or you can simply collect data and monitor the conditions of your land. The diversity of smart garden tech will prove beneficial instead of daunting once you find the tools to fit your needs.

Focus on your goals

Like their indoor counterparts, every smart garden device does one or both of the following: senses the environment around it and/or automates a task. Smart outdoor devices will thus help you learn about your environment, help it thrive or both. Robot lawn mowers focus mostly on automation, but still need to sense enough to stay within the boundaries of your yard. Both plant sensors and weather monitors focus mostly on senses, but can still send you push notifications and act as triggers for other automation devices. Connected sprinklers gather weather information, and use it to automate a watering schedule.

Except for some robot lawn mowers, all smart outdoor devices have accompanying apps and communicate with the cloud in some form or another. And that’s the end of the similarities of smart garden tech. Given how vastly different the devices are, you can quickly narrow your choices just by focusing on what you’d like your new smart gadget to accomplish. Are you a seasoned gardener looking for assistance to help you save time? Are you an enthusiast trying to collect data? Are you a busy homeowner hoping to cut your water bill? Are you an apartment dweller who struggles to keep a houseplant alive?

Connected garden tech can help with any of these goals.

Plant sensors

You place these devices into the dirt near your plants, where they gather information on the surroundings and send it to your phone, tablet or computer, ideally to help you become a more informed gardener.

This is the only category of smart outdoor tech that can actually be used indoors, making them great for keeping a potted plant alive. Even the simplest plant sensor we’ve seen measures soil moisture, and compares that info against a plant database to give you specific advice about when to water that species of plant. You’ll even get push notifications reminding you to water from all plant sensors we’ve tested, so you can steer clear of accidental procrastination.edyn-product-photos-3.jpg

The Edyn Garden Sensor measures moisture levels, nutrition levels, temperature, humidity and ambient light.Tyler Lizenby/CNET

More advanced plant sensors measure criteria such as ambient light, humidity, temperature and even levels of fertilizer in addition to the basic moisture readings. They can also measure multiple plants at once, so you’ll be able to use a single sensor to watch a whole garden.

You can expect plant-specific recommendations on each criteria your plant sensor measures. Some plant sensors even keep careful track of the numbers they collect, making them the right tool if you want to study the conditions of your garden over time.

Plant sensors are a great tool for beginners and can provide valuable assistance and reminders to seasoned gardeners as well.


Using weather reports and sometimes data from your garden, these systems can help you save water by giving your yard a drink when it needs it, then automatically adjusting the schedule to stay off when it rains.

The Blossom Smart Watering Controller.Tyler Lizenby/CNET

Most of these devices replace the controller of your existing irrigation systems, making them a fit for homeowners looking to save time and money. You won’t have to fuss with your sprinkler schedule and can trim the amount of water your sprinklers use while keeping the yard green.

Smart sprinkler controllers vary in the number of zones they can control — from 6 to 16 — so check into how much coverage you need and how much the specific device offers when making your purchase.

If you don’t have an irrigation system, you have a couple of hose-fed options. These serve the same purpose as smart irrigation controllers, but can be threaded into more basic watering systems.

Weather sensors

Even more of a niche item than most smart garden tech, weather sensors can be quite useful in certain scenarios. They’re the optimal device for learning more about your surroundings in general. Plus the included sensors can be used to monitor sensitive areas of your home, like a wine cellar or a child’s room. Short of having a specific use in mind though, you might not find much value in these devices beyond what you can get from the dozens of free weather apps.

We’ve only seen two weather monitors thus far. Bloomsky adds value by taking periodic pictures of the sky over your house and letting you create time-lapse videos with them, in addition to providing hyper local weather. The Netatmo Weather Station adds value by monitoring your indoor air quality in addition to outdoor metrics like temperature and air pressure.bloomsky-product-photos-2.jpg

The BloomSky Sky2 is expensive, but has an impressive list of features.Tyler Lizenby/CNET

If you’re interested in hyperlocal weather, one of these devices will work for you.

Robot lawnmowers

Robot lawnmowers could be useful for many once the category has had time to mature, but as it stands, the tech is new, expensive and unwieldy. The benefits of robot lawnmowers are obvious — you will no longer have to spend time pacing up and down your grass to keep it from overgrowing. Just be ready to spend more than $1,000 for the privilege.


The $1,600 Robomow RS612 worked well after a tedious setup period. It’s first couple of runs also delivered spotty results.Tyler Lizenby/CNET

You’ll also need to go through a setup process. As it stands, robot lawnmowers navigate the yard using wires placed around the perimeter as guidelines (it’s the same tech that is used for electric dog collars). After your purchase, but before starting to use the machine, you’ll need to bury these wires around your yard.

So the barrier to entry into robot grass cutting is high at the moment, but if you’re willing to invest the time and money to get over that hump, you could cross one of your items off of your regular chore list. Before you splurge, consider hiring a gardener, as that might actually be cheaper.

Asking the right questions

What type of signal does the device use?

Though your options are many, the Internet is a key ingredient in any smart garden device, so it’s important to note how exactly your tech will reach the cloud.

Plenty of devices connect directly to your Wi-Fi router — allowing you to interact with them remotely. A Wi-Fi enabled device works well in most scenarios, unless you want to place a plant sensor in the far corner of your big yard, or put your sprinkler controller behind a concrete wall.

If that’s the case, you might need a device with a specialized signal. Your options include frequencies such as Z-Wave and ZigBee — which use less power than Wi-Fi, but need a hub to translate the signal for your router. The Blossom Smart Watering Controller supplements its Wi-Fi signal with a power line connection, which uses the electric wiring in your home to transmit signals.

You might also find devices that use Bluetooth, which connects directly to your smart phone and uses less battery than Wi-Fi, but doesn’t let you access your device remotely. The GreenIQ Smart Garden Hub — a smart sprinkler controller — goes one step beyond Wi-Fi using cellular signal provided by US carrier AT&T, allowing you to stay connected to your device even if your router fails.

GreenIQ connects to AT&T’s 3G cellular signal.GreenIQ

Is it weather-proofed?

If you’re going to keep your new smart device outside, you’ll want to check and see if it can hold up to the conditions. You might expect that every device in the smart outdoors category can endure weather, but that’s not necessarily true. Blossom is weather-proofed, the competing Rachio Sprinkler isn’t (Rachio does sell a waterproof enclosure). You shouldn’t submerge the Edyn Garden Sensor, but it can take normal rainfall.

Double check how much weather your device can take before making your purchase, and double check it’s operational temperature range if you live in particularly hot or cold climates. Even if you have four typical seasons, you’ll need to bring most plant sensors back inside before winter strikes.

How is it powered?

Most plant sensors and weather monitors require batteries, so you’ll want to check what type of batteries they use as well as how long those batteries typically last. The Edyn Garden Sensor gets a nice boost here, as it has a built-in solar panel that recharges its specialized battery with just a sunny day.

Others use AA or AAA, which is where Bluetooth devices or those with specialized signals get an advantage, as those signals typically use less power than Wi-Fi. Most devices provide an estimated battery lifetime.

Robot lawnmowers charge up using an included station that plugs into any outlet. You’ll want to check how much charge the lawnmower holds though. Mowers with a bigger battery capacity can mow a greater area before coming back to the station.

With irrigation controllers, power isn’t usually a factor, since you’ll be replacing your existing controller and can plug your new smart device into the same spot.

Is it compatible with your phone or tablet?

Since you’ll generally need an app to operate your smart gardening device, check to be sure the device has an app you can access. Most of these apps are free, so you can download the corresponding one before purchase to get a glimpse into how it looks and feels. Once you have your device, the app will be your main source of interaction with it.

With plant sensors, the app provides care advice. If you want plant-specific care advice, explore the plant database of the app and make sure it has your plant or a species close enough to give useful recommendations.

If you’re interested in plant sensors or weather monitors for their data, make sure the charts are readable, specific and helpful. For sprinkler systems, check out your scheduling options and make sure it’s intuitive to set them up.

Does the device play well with others?

Many of the devices in the smart outdoor family will talk to smart devices you have setup inside your home. An interconnected smart home doesn’t have to stop at the outer walls. The advantages of this could be many — the more devices you have that work together, the more chores you can automate.

A completely interoperable smart home like in “The Jetsons” isn’t feasible yet, but thanks to online rule maker If This Then That ( IFTTT) and other systems that unify third-party devices, you can tell different tools to work together in interesting ways. For example, when your Nest Protect senses a fire, it can send a signal through IFTTT to the compatible Rachio to turn on your sprinklers.copy-of-rachio-sprinkler-controller-gen-2-installed-2.jpg

The Rachio Sprinkler has an IFTTT channel.Rachio

If weather monitors or plant sensors can talk to your sprinklers, the amount of water distributed will be that much more customized. If accidental negligence is a big problem for you, a plant sensor that talks to IFTTT can go one step further than a push notification and flash your connected lights when it’s time to water.

An IFTTT channel allows the creation of these third-party rules, and it’s one of the most popular ecosystems at the moment, so I’d give an advantage to smart outdoor devices that are compatible with IFTTT over ones that aren’t.

The smart garden is also taking tentative first steps into voice controls. Smart sprinklers GreenIQ, Blossom and Rachio all work with Amazon’s always-listening speaker the Amazon Echo. Give a command to Amazon’s assistant Alexa, and you can turn on your sprinklers without even opening an app. Rachio also works with the Google Assistant for similar controls with the Google Home — a voice controlled speaker similar to the Echo.

You might not want or need your smart gardening device to work with other smart devices. But keep in mind that once you get started with home automation, you might enjoy the benefits enough that you want to keep building your smart home. At that point, interoperability could come in handy.

Making the right choice

Once you decide what you’re trying to do and pick your category, making the right choice comes down to choosing the features you want. Don’t pay more for an irrigation controller with 16 zones if you can make do with eight. If you’re never going to move a plant, you probably don’t need a plant sensor that measures temperature or sunlight, since you won’t be able to effectively alter either.

If you simply need push notifications to help you remember to water, you can also get creative and set that up yourself for free. Sometimes, apps can be quite useful with or without the product, and again, you should always take a tour of a device’s app before making your purchase.

With the right devices on your side, your yard can practically maintain itself. Get smart with your yard care, and you can use the power of the Internet to make your neighbors jealous.