Discover which irrigation system is best for watering your garden
Most plants need regular watering to survive, and even the most drought-tolerant ones will occasionally need a drink. Many factors play a role in determining how best to accommodate your garden’s water requirements.
Do you have a variety of water needs?
Drought-tolerant plants, lawn areas, perennial beds and edible gardens all require varying amounts of water and frequency. When planning your yard or garden areas, think ahead about how much water individual plants need and group plants together that are similar. This will make watering easier to manage (and save water) when all the plants in one area get the same amount of water and at the same frequency. It also helps to keep neighboring plants healthy by not overwatering dry-loving plants or underwatering water-loving plants, simply because they are located next to each other. Also, keep in mind that the shallow roots of annuals will need more frequent watering than deep-rooted perennials.
What is your climate like?
Hot and windy or cool and cloudy call not only for different amounts of water, but different methods of application as well. When it comes to climate, simply making sensible plant choices is one of the best things you can do for your garden – trying to grow tropical plants in the desert will only cause yourself, and your plants, a lot of stress.
What is your average rainfall?
Adjustments for rainfall can happen daily, weekly, monthly or seasonally. If you’re lucky enough to live in an area where Mother Nature takes care of some of the watering for you, make sure you have a watering system that lets you adjust accordingly.
Is your site flat or sloped?
Application methods and rate will be different for water that is going to stay put on a flat surface and soak in or if it’s going to run down a slope. Figuring out the correct watering schedule and amounts for flat ground can be difficult enough with differences in water needs, soil types or exposure; but watering on slopes adds another layer of complexity. Considerations need to be made to compensate for gravity, trajectory angles and pressure differences due to elevation changes. Check valves should also be installed on lower levels to keep residual water from leaking out.
Does your garden get a lot of sun or is it shaded?
Evaporation from bright sun can steal precious water in a sunny garden by as much as 50%. Shaded areas hang on to moisture longer and may become waterlogged. Define the different areas, or zones, of your entire yard or garden. Areas that receive full sun would probably do better with drip or soaker-type irrigation that protects against evaporation, as would areas that are prone to wind. Zones that are constantly shaded should be on a different schedule than those in sun, as they will soon become overwatered compared to the hotter, drier areas.
What is your soil composition?
Sandy, clay, rich, rocky — all play a part in how well water is absorbed and eventually drained from an area.
Clay soil is often referred to as heavy. Water is absorbed slowly and spreads out, and clay can hold a lot of it. It’s best to water clay soils at a slow rate to allow it to soak in. Clay soil is prone to cracking when it dries out and roots can have a hard time penetrating it. The best amendments for clay soil are compost or organic matter to improve drainage.
Sandy soil allows water to soak straight down without holding onto much of it. Plants will need to be watered more often and in a wider arc to get roots to spread. The best amendments are compost or organic matter to help hold in the moisture.
Loam soil is a combination of sand, silt and clay and the best for plant growth. Loam is rich with nutrients and distributes water evenly with good drainage.
Most gardeners will have a combination of answers to the above questions — you may have some areas in sun and some in shade; a mixture of level surfaces as well as slopes; or some areas may get more wind than others. A good understanding of all of these factors will help you make the best choices in matching the right garden watering system — or combination of systems — to the individual needs and areas in your garden.
Depending on your answers to the above, choosing the proper irrigation method can be confusing. Here’s an overview of the most common options:
Pop-up underground systems that spray water are usually used as lawn irrigation systems or to broadcast water over a large area. They can be quite wasteful, using a large amount of water and allowing up to 50% of it to be evaporated on hot, windy days before it even reaches its destination. Another disadvantage is that by broadcasting the water from overhead, fungal diseases that thrive on wet foliage can be spread easily. One advantage, however, is that the amount of water and the area it is sprayed on can be adjusted and tailored to the size and shape of your lawn. Additionally, they are generally less expensive than other options.
A system of tubing and nozzles (emitters) allowing you to pinpoint exactly where the water is going. Drip irrigation systems take some planning to install, but conserve water by putting it only where it needs to be and applying it at a rate slow enough that none is lost to runoff or evaporation. In areas where water is scarce or use is restricted, drip systems can make the best use of a garden’s water allowance. Another advantage is that foliage stays dry and fungal diseases aren’t as easily spread.
Similar to drip systems, although much less expensive. Soaker hoses release water directly into the soil, and the water conservation benefits are the same as with drip systems. There are various types of hoses made of plastic, rubber or canvas. Some are designed to permeate water through their entire surface and others have tiny holes. They can be moved throughout the garden and turned on and off manually, or left in place and hooked up to a timer-controlled valve.
Probably the most inexpensive option as far as equipment costs; however, portable sprinklers can be very inefficient. Most spray water into the air and much of it may evaporate before reaching the ground or be blown in the wind to other areas. Sprinklers often put out water faster than the soil can absorb, leading to waste and runoff. However, they can come in handy for spot watering a small area.
If you prefer a more hands-on approach, don’t have a terribly large area, or just need to spot water, then pick up the hose and get watering. One benefit of watering by hand is it gives you some face-to-face time with your garden. Watering with a hose can be wasteful, but if that’s not a concern where you are, then by all means, get out in your garden and spend some time.
If you’ve only got a few container plants or a very small garden, a good old-fashioned watering can can do the trick. Watering cans allow you to place water at the base of the plants to keep the foliage dry, or to water from the top to give plants a gentle rinse. They also come in handy for watering indoor plants.
These specialized containers have an upper pot that holds the soil and plant, while a lower reservoir holds water that is wicked up into the soil. Usually, these pots will hold enough water for a few days, depending on the weather and evaporation rate. Although they are called self-watering, water still needs to be added to the reservoir every few days.
Tree and Shrub Bags
To help new trees or shrubs become established, slow, deep watering is best. Tree watering bags are filled with water and release it slowly into the ground, allowing full saturation of the area surrounding the rootball. Bags are inexpensive and also save water by not allowing any runoff.
AUTOMATIC IRRIGATION EQUIPMENT
Make watering your garden completely automatic with timers, controllers and valves that can turn the water on and off on a set schedule or based on the weather.
Irrigation timers connect directly to a water source and allow timed release of water through a drip system, soaker hose or regular garden hose. Knowing that your plants are getting watered regularly while you’re away or are too busy to do it yourself can be a relief. However, remember that a basic timer without a rain sensor will still keep its watering cycle even on rainy days.
Automatic sprinkler controllers connect to sprinkler or drip systems through a valve system. They are electronic, programmable, and allow for multiple stations. Like timers, unless equipped with rain or moisture sensors, they will continue to run as programmed even through the rain. Installing a wifi-enabled controller allows you remote access to make adjustments needed while you’re away — whether it’s delaying watering due to rain or adding some extra time if a heatwave passes through.
Most valve systems are wired to a controller for automatic operation, although there are manual systems as well. Valves tap into a water source and each valve serves one station, or irrigation line. The number of valves needed will be dependent on the area to be irrigated and your water pressure.
WATER COLLECTION SYSTEMS
With drought and water conservation becoming the new normal in many areas, homeowners are trying to get the most out of every drop. Water collection systems provide homeowners a way to save both water and money.
Rain barrels, rain traps, cisterns and overflow kits can be put to good use collecting rainwater. Rainwater has many benefits besides conserving a precious resource and, well, it’s free. Rainwater is simply better for your plants because it doesn’t contain the added chemicals such as chlorine and fluoride commonly found in tap water. If sodium is added to tap water as a water softener, it can be damaging to the soil as well. Rainwater also contains nitrogen, the element that makes plants green, which is absorbed immediately by the roots and leaves – giving that fresh look to plants like after a good rain. If you’re planning on installing a rainwater collection system, be sure to check out your local and state laws and regulations.
Similar to rainwater collection, greywater from sinks, showers and washing machines can be collected or diverted directly to the garden. Just be sure you are using ‘plant friendly’ products (soaps, cleaners, etc.) in any water that is used.
“Irrigation 101 – Watering Your Garden” Linda Hagen, Retrieved 19 July 2019. <https://www.gardendesign.com/irrigation/>