What Kind of Landscaping Is Best for Frisco? Ask an Expert!

By Darell S. Bagley, ASLA
Sr. Landscape Architect
City of Frisco
dbagley@friscotexas.gov
(972) 292-5352

How to design a beneficial landscape that:
• Uses 50% less water
• Protects water resources
• Lowers maintenance
• Pleases the eye
• Saves you money

A Budget for Your Landscape?

I am not referring to the money you set aside for landscaping purposes – I’m talking about a water budget. Most families understand the reality of a budget. You look at your income and then compare with your expenses to see if you have enough income to cover those expenses. If you don’t have enough income you have some choices – you can cut back, try to increase your income or do both.

The Bank Account

The plants in nature and in your landscape work in much the same way. All plants require a certain amount water to survive and flourish. When water is in great supply, such as during a rainy season, plants will use all the water they can get to grow. During dry times, plants know how to conserve water.

Think of it like a bank account. Rainfall to a plant is like your pay check being deposited in the bank. After you get paid, you have expenses to meet your family’s need and wants.

A plant has needs too. It needs to pull water up through its roots and all the way out to the leaves to conduct photosynthesis. During this marvelous exchange, the sun’s energy is used to take carbon dioxide in through the leaves to make food for the plant while oxygen and water vapor are released into the atmosphere to continue the hydrologic cycle. When a plant releases water vapor through the stomata (think “pores”) of its leaves, it is called transpiration, and it is a necessary expense for the growth of the plant.

Not all of the water loss comes from transpiration. Some of the water evaporates before the plant can use it. Scientists have combined both words to get “evapotranspiration” or ET for short. Rainfall is the” deposit in the bank” and evapotranspiration is the withdrawal from the bank.

Nature’s Way

Native plants in North Texas have adapted to rainy springs and hot dry summers. On average the plants of this region get about 36 inches of rain deposited into their account each year. A good portion of that rain comes in the spring, right when the plants need it most, at the onset of growth after winter. During the summer months when it gets hotter and dryer, these plants conserve water by closing the stomata (pores in the leaves). It is beautiful system and it all works quite well without our help.

Now we come to the plants in your landscape. In Frisco, about 70% of our drinking water is used to water for landscapes, and water usage reaches its peak during the hottest part of the summer (typically August). This is because many of the ornamental plants, brought in from other regions, are not adapted to North Texas and they don’t know how to conserve water during the summer months. We tend to over water these exotic plants to compensate.

Now, let’s consider the lawn. Most Frisco lawns are Bermuda grass, which is native to South East Africa, a tropical region. It can be fairly drought tolerant but we tend to fertilize with too much nitrogen and water it too frequently, to get that lush green look, which results in all top growth and not much root. When the summer months hit, it can’t handle it, so we throw on more water and fertilizer to keep that lush green look – not good for conservation or your pocket book!

Back in Harmony

How do we get our landscapes back in harmony with nature and still have beautiful attractive landscapes that we can be proud of? Here are a few suggestions:

• Develop an annual water budget for your landscape

First, develop an annual Landscape Water Use Budget with the goal of reducing your landscape watering by half. You can determine this by getting the total landscape area of your property by taking the area of your lot and subtracting the house footprint and any paved surface. We have a calculator on our web site to help you calculate this budget or you can use the following formula:

LWUB=(56 )(.62)(LA)/2

The average reference ET (ET0) in the Frisco area is 56 inches, so first take your landscape area and multiply it by 56. Next multiply it by .62 to convert it to gallons. Divide the gallons by half and that is your annual landscape water budget. You will want to subtract out your indoor water consumption (usually about 8,000 to 10,000 gallons per month). You can also look at a winter water bill when you are not watering landscape plants to see how much you are using outdoors and then compare that with your water budget.

• Estimate Your Landscape Water Use

First notice your landscape is divided up into zones. A typical landscape in Frisco has a turf zone (usually Bermuda grass), and a shrub and ground cover zone. Your shrubs and flower beds should be watered separately from your turf and will require quite a bit less water.

If you have an automatic irrigation system it is probably designed to run this way. You will want to estimate the amount of square footage in each zone and enter those numbers into the spread sheet calculator. After you enter those numbers the calculator will automatically show you if you are over budget.

What can you do if you are over budget? First you can change your nozzles to more efficient ones as discussed below or you can change out some of that turf to a Natural Landscape zone. A Natural Landscape Zone is a landscape area composed of native plants and plants from other regions of the world with similar climates to ours that can conserve water when the going gets tough. They can do just fine without irrigation, once established. Attractive perennials, grasses, shrubs and trees, that fit this classification abound. Check our web site, Texas SmartScape, or contact me for help for suitable plants for this zone. If you plant Buffalo grass or one of its hybrids in place of thirstier turf types such as Bermuda and Saint Augustine, you can treat that zone in your water budget as a Natural Landscape zone resulting in a significant savings.

Another landscape zone to consider is a Water Resource zone. This zone allows you to use rainwater that would normally runoff as a resource. This can be done by creating a slightly depressed area in your yard and directing rainwater from the roof or paved surfaces to it. “Rain gardens” as they are called, can be very attractive when planted with perennials, grasses and other plants adapted to the conditions of being sometimes wet and sometimes dry. If your soil does not drain within twenty four hours, you should provide drainage. (Stay tuned to Frisco Green for a future article on how to construct a Rain Garden.) Please see the city of Frisco web site, Texas SmartScape or contact me for a list of plants suitable for both of these zones.

• Choose Efficient Irrigation

Now that your landscape is designed with more efficient plant zones you want to choose efficient irrigation to compliment it. Remember, the goal of irrigation should be to supplement that bank account when nature is not complying with rain.

One of the easiest ways to do this is with a “Smart Controller”. These will be discussed in more detail in a future article, but a smart controller allows you to water each of your zone types appropriately and automatically adjusts when and how much water it applies, based on weather conditions.

If you program it to water Buffalo grass or a natural landscape zone it will water much less (if at all) than if you program itf for Bermuda. You may also program it to water your Bermuda grass less and still keep it looking green.

Keep in mind that when you water your lawn, you will have a healthier lawn by putting down 1″ of water per week all in one day rather than spreading it out to water a little bit every day. It will encourage deeper roots that can withstand longer periods without rain or irrigation and still maintain the green look. Just remember to not let the water run off your landscape and into the street.

Next, let’s take a look at the sprinklers. The first consideration is to avoid runoff. This can be done by choosing a type of nozzle that has a low precipitation rate (the rate at which the water is applied in inches per hour), especially for areas adjacent to streets and other pavement. Most major irrigation manufacturers now make efficient low precipitation nozzles, resulting in more water on your landscape and not the street. Drip irrigation is the most efficient because the water is applied directly to the plants and very little is lost to the wind and evaporation. However if you are going to be digging in your beds or aerating your lawn keep in mind that the drip tubing can be damaged.

Following these tips will result in a landscape that:

• Uses 50% less water
• Protects water resources
• Lowers maintenance
• Is Highly attractive
• Saves you money

Your landscape will be in harmony with nature’s way of doing things and will conserve precious water resources vital to our future.

Tags: City of Frisco, Darell Bagley, evapotranspiration, Frisco landscaping, water budget, water management