Course: Landscape Design & Turf Grass Management

Unit Title: Watering Landscape TEKS: 130.19(C)(5)E)

Instructor: Ms. Hutchinson

Objectives:

After completing this unit of instruction, students will be able to:

A. Discuss the functions of water in plant growth and development;

B. Explain the effects watering has on landscape plants;

C. Describe how to determine when landscape plants need watering;

D. Discuss methods of watering landscape plants;

E. Explain how to determine the quantity of water to apply to landscape plants;

F. Explain how to determine the time and frequency for watering landscape plants;

G. Describe effective and efficient watering practices used in watering landscape plants;

H. Discuss the importance of water quality considerations;

I. Place pots 4 pots of soil from highest moisture content to lowest moisture content; and

J. Demonstrate how to water using a water hose and a bucket.

Interest Approach:

Students would have already done work and planted flowers in a flowerbed. Ask students questions

now as to what they think we need to do to maintain the flowerbeds so everything doesn’t die.

Curriculum & Instruction:

Curriculum

A. Discuss the functions of water in plant growth and development;

Functions of Water in Plant Growth and Development:

Provides essential nutrients. Major component of plant cell. Solvent and medium for chemical reactions and

processes Maintains turgidity. Medium for transporting nutrients and food. Component of photosynthesis. Assists in the movement of plant parts Maintains stable temperature within plant.

B. Explain the effects watering has on landscape plants;

Water and Turgidity:

Water is important for keeping plants and their cells turgid.

Turgidity is a plant state in which the plant is rigid and inflated with water.

Plants may appear wilted due to a lack of turgor pressure.

Turgor pressure is the pressure inside a cell due to water uptake.

Water and Temperature Stability:

Water serves as a buffer against sudden changes in the environment.

Cold temperatures = water maintains plant energy and uses it to moderate the

Instruction

PPT Slide 4-10 What functions does water serve for plant growth and development?

temperature of the plant Warm temperatures = water releases heat to

cool the plant

Water Functioning in Soil: While absorbing water from the soil, plant roots also

absorb minerals that have been dissolved in the soil water.

Plants lose a great deal of water due to transpiration and replace this lost water with moisture from the soil.

Transpiration - plant releases water from its leaf surfaces in the form of water vapor.

Leaching occurs when nutrients are washed past the root region and become unavailable to plants.

Water applied to the soil helps leach out excessive levels of minerals in the soil near the plant’s roots.

Water and Landscape Plants:

Landscape plants require adequate water to survive. The amount of water a plant receives affects its growth

and development. Both under-watering and over-watering impact plant

growth and development. Determine whether plants need to be watered by

observing them for signals or by checking the soil for moisture.

Effects of Under-Watering:

Reduced growth rate. Result is small, newly developed leaves and a

stunted, hardened appearance. Reduced rate of photosynthesis. Wilting due to decreased turgor pressure when plant

transpires faster than roots can supply lost water. Eventual death due to lack of water and permanent

wilting. Effects of Over-Watering:

Taller growth with less compactness. Shallow root system. Nutrient deficiencies due to leaching and shallow root

system. Plant roots may “drown”

Die due to lack of oxygen needed for respiration

Occurs most often in heavy clay soils because water is held in the soil and the plant is not able to absorb the water, thus resulting in a lack of

PPT Slide 11-12 What are the effects of under-watering a plant? What are the effects of over-watering a plant?

adequate air.

C. Describe how to determine when landscape plants need watering;

Signals that Turfgrass Needs Water:

Wilting in which leaves bend or roll up. Overall dull, grayish appearance. Leaves appear dull with a bluish-green to purplish cast. Grass lies flat after being walked on. Intrusion of weeds.

Signals that Trees, Shrubs, and Groundcovers Need Water:

Discoloration in which leaves go from glossy, bright-green to dull, gray-green.

Wilting. Premature leaf, bud, and flower drop. Death of young leaves.

Watering Needs of Container Plants & Transplants:

A high potential for drought stress occurs in container plants because moisture from the surrounding soil does not move into the container soil mix and root zone quick enough to prevent drought stress.

Frequent watering is necessary until the root systems of transplanted plants spread and develop into the soil of the new location.

Check for Soil Moisture:

Cane or Stick Insertion Insert a cane or stick into the soil around the

root system. If it has no moisture or no soil clinging to it

when removed, water is needed. Moisture or soil clinging to it indicates

adequate moisture. Observing the Soil

Soil appearing light in color and dry to the touch indicates a need for watering.

Feeling the Soil Roll or squeeze a small bit of soil into a ball. A soil ball that crumbles when rubbed has

proper moisture. If the soil ball does not crumble when rubbed, it

is too wet. Water is needed if soil will not form into a ball. Sandy soils crumble even when wet.

PPT Slide 13-15 What are the signals that turfgrass needs water? How do you know that trees, shrubs, and groundcover need water? What the watering needs of container plants and transplants?

PPT Slide 16-17 How do you check soil moisture with a stick? How do you feel the soil to decide if it needs water or not?

D. Discuss methods of watering landscape plants; Methods of Watering Landscape Plants:

Sprinkler Irrigation Drip Irrigation Surface Irrigation Manual Irrigation

Sprinkler Irrigation:

Most commonly used method of irrigation. Effective and efficient method of evenly distributing

water over a lawn area. Applies large volumes of water in a short time. Requires minimal maintenance. Includes hose-end sprinklers and automatic

underground pop-up sprinkler systems. Types of Hose-End Sprinklers:

Oscillating Sprinklers Spray Type Sprinklers Impact Sprinklers

Oscillating Sprinklers:

Provide an even supply of water back and forth across an area.

Maintain an even watering pattern throughout lawn area.

Should be moved frequently and evenly throughout the area.

Should overlap about half of each pattern when moved.

PPT Slide 18-38 What are the 4 types of methods to water landscape plants? What is the most common method of watering plants? What are the types of hose-end sprinklers?

Spray Type Sprinklers:

Distribute water to an area either with a fixed spray or rotary spray.

Provide a constant, uniform supply of water to an area.

Impact Type Sprinklers:

Shoot a fine spray of water across an area. Impact of water passing through the sprinkler nozzle

changes the direction of the stream in short movements around the sprinkler.

Those on risers of about 2 to 3 feet sprinkle water above shrubs, providing a more equal distribution of water.

Selecting a Hose-End Sprinkler:

Choose one that sprays large water drops, close to the ground.

Avoid sprinklers that produce fine streams of water high into the air.

Much of the water from these will be lost due to evaporation.

Automatic Underground Pop-Up Sprinkler Systems:

Consists of the following components: Underground distribution lines. Electrically controlled valves. Electric program controller.

What are the guidelines to selecting a hose-end sprinkler? What components are needed for underground pop-up sprinkler systems?

• Allows user to determine day of week, time of day, and number of times to water each area.

Pop-up sprinkler heads.

Advantages

More water efficient than hose-end sprinklers. Sprays water near the ground and closer to the

roots of plants. Allows for dividing areas into zones that can be

watered separately, according to specific needs. Disadvantages

Expensive to install. Nozzles may require cleaning if clogged. Heads and nozzles may have be adjusted to

ensure walks and drives aren’t watered and large drops rather than a fine spray is emitted.

Drip Irrigation Systems:

Involves the following components: Supply tubes

• Supply water to the system. Thin connecting tubes

• Connect supply tubes and emitters. Emitters

• Drip water to the root zones of plants.

Advantages of Drip Irrigation Systems:

Efficient Water is slowly dripped into the soil in the root

zones of plants, eliminating water waste. Allows plants to be watered in zones, satisfying

What are the advantages to a underground pop-up watering system? What are the disadvantages?

What components are needed for the drip irrigation system? What are the advantages of drip irrigation?

different water requirements. Economical

Operates on low pressure, uses less water, and reduces water costs.

Improved Plant Health Promotes deeper and more extensive root

growth because water is applied slowly, allowing for deeper water penetration.

Plants experience less stress. Disadvantages of Drip Irrigation Systems:

High cost of materials and instillation. Emitters may occasionally become clogged.

Guidelines for Use of Drip Irrigation Systems:

Operate system for at least three hours to achieve thorough soaking.

Bury supply tubes and thin tubing, or cover them with mulch.

To hide tubes from view. To add to the life expectancy of the system.

Surface Irrigation:

Involves flooding or allowing water to cover an area. Commonly used in landscape for watering flowerbeds. Also used in landscape for close plantings of trees or

shrubs.

Advantages

Provides good, uniform wetting of the soil in the irrigated area.

Disadvantages Uses a great deal of water. Requires a level surface, or runoff becomes a

problem. Guidelines for Surface Irrigation:

Construct small berm around area to be watered. The berm creates a small basin to retain water and to

prevent surface runoff. Allow water to cover the soil surface to a depth of 1 to

What are the disadvantages of drip irrigation? What are the guidelines to a drip irrigation system?

What are the advantages of surface irrigation? What are the disadvantages?

2 inches

Manual Irrigation:

Involves watering landscape plants by hand. Supplies water to plants by means of a hose or bucket.

Advantages

Allows each plant to be personally monitored by the irrigator.

Disadvantages Requires a great deal of time. Requires a lot of labor. Requires a lot of water.

Using a Hose for Manual Irrigation:

Make sure hose reaches all plants to be watered. Attach a water breaker to end of the hose.

Breaks force of water flowing from the hose. Directs soft flow of water to concentrated area

without washing away soil. Trigger type nozzle will wash away soil.

Using a Bucket for Manual Irrigation:

Apply water slowly.

What is manual irrigation?

What are the advantages and disadvantages of manual irrigation? Why do we need to attach a water breaker to the end of a hose for manual irrigation?

How should you use a bucket for manual irrigation?

Do not pour all water at once. Applying all at once washes away soil.

Apply water close to the soil surface. Do not pour from a height of more than 6

inches from the soil surface.

General Guidelines for Manual Irrigation:

Fill the basin surrounding the base of the plant. Allow water to infiltrate down into the soil in the plant’s

root zone. Do not allow excessive water runoff. If no basin exists, apply water away from the trunk or

stem to the canopy drip-line.

Factors to Consider in Selecting an Effective Irrigation Method:

Size and topography of area Type of plants Labor requirements (time and cost) Uniformity of application Quality, quantity, and availability of water Cost of installation Life expectancy of system Economics of operation

E. Explain how to determine the quantity of water to

apply to landscape plants;

What are the guidelines for manual irrigation?

PPT Slide 39

F. Explain how to determine the time and frequency for watering landscape plants;

Determining Quantity & Frequency of Watering:

Watering needs differ among landscape plants. Factors to consider in determining how much water to

apply to plants include: Plant Species

Some species prefer continuously moist soil conditions, while others prefer moderate or dry soil conditions.

Drought tolerant plants require less frequent watering than others.

Trees and shrubs with deeper root systems require less frequent watering than ground covers and turfgrass with more shallow root systems.

Plant Size Large plants have more root surface area than

smaller plants, and therefore require a greater amount of water than smaller plants.

Plants with large leaves lose more water due to transpiration than those with smaller leaves, and therefore require more frequent watering.

Plant Age and Stage of Plant Development Newly planted plants require more frequent

watering than established plants. Young, rapidly growing plants should be

watered more frequently than older, mature plants.

Older plants withstand moderate drought conditions easier than younger plants.

Soil Texture Water moves through clay soils slower than

sandy soils. Clay soils retain water longer than sandy soils. Coarse-textured sand is more open and aerated

than fine-textured clay. Sandy soils require more water and more

frequent watering than clay soils. Slope of Land

Water from rainfall generally moves across the soil surface and down the slope.

• During heavy rainfall, not much water infiltrates into the soil on sloped areas.

• Between rains, sloped areas require more supplemental watering than level areas.

PPT Slide 40-45 What are the factors to consider when determining how much water to apply to plants?

Environmental Conditions More water and more frequent watering are

needed during warm months as compared to cooler months.

• Thoroughly water every 7 to 10 days during dry weather.

Plants use less water on cloudy days than on bright, sunny days.

Plants use less water in conditions of high humidity and slight air movement.

Guidelines for Determining Quantity of Water to Apply:

Apply enough water to thoroughly soak the soil surrounding the plants’ roots.

The soil should be moist to a depth of 8 to 12 inches in the location of feeder roots.

Soaking the soil to a depth of 6 inches requires 1 to 2 inches of surface water.

Failure to thoroughly soak the soil leads to a shallow root system that dries out quickly during hot, dry weather.

Apply water at a slow enough rate to prevent runoff. If runoff occurs, the rate of application is too

rapid or the soil is already soaked. Apply water regularly to newly planted landscape

plants. Newly planted plants dry out faster than

established plants. Satisfy the water requirements of established plants.

During the active growing season, most plants need 1 to 2 inches of water every 1 to 2 weeks.

Avoid applying too much water. Waterlogged soils compacts easily and promote

rotting and disease infection of plants. Consider water received in the form of rainfall.

In heavy rains, plants receive substantial amounts of water, but in light rains, plants receive little water.

Consider the placement of plants. Plants under eaves or close to a wall do not get

as much natural rainfall; therefore, they need supplemental water.

Determining the Effectiveness of Landscape Watering:

1. Water an area for 15 minutes. 2. Dig to find the depth of moisture penetration. 3. Calculate the time needed to thoroughly soak plants

based on the depth of moisture penetration.

What are some guidelines for applying water?

Thoroughly wetting the root zone of an established large shrub or small tree may require 6 to 12 hours.

Determining Water Quantity Received by Lawn Area:

1. Set several wide-topped, flat-bottomed cans with straight sides in a straight line out from sprinkler.

2. Check the water level in the cans at 15- minute intervals.

3. Adjust the sprinkler’s rate of application to about ½ to 1 inch per hour.

Time for Watering Landscape Plants:

Water during the early morning hours. Calm winds and a cooler temperature reduce

water lost to evaporation and ensure a uniform watering pattern.

Discourages development of disease-causing pathogens because foliage dries in a short time.

G. Describe effective and efficient watering practices

used in watering landscape plants; Tips for Effective and Efficient Watering:

Water plants only when they need it and apply only enough to satisfy their needs.

Water plants thoroughly to reduce the amount of water and frequency of watering.

Mulch landscape plants to keep soil cool and to reduce water lost to evaporation.

Add organic matter to increase drainage in clay soils and to retain moisture in sandy soils.

Avoid watering weeded or unplanted areas. Taper off watering during late summer and early

autumn to encourage plants to harden and become tolerant to cold winter conditions.

Water plants periodically during the winter to supply water to plant roots as they continue to grow.

Things to Remember About Effective and Efficient Watering:

How do you determine the effectiveness of your watering? How can you determine water received by a lawn area?

PPT Slide 46 What time of day should you water your plants?

PPT Slide 47-49 What are some tips to effective and efficient watering?

The greatest waste of water is due to applying too much, too often.

Be observant in hot and dry summer weather when plants never absorb and use much of the water applied.

As much as 50% of water is wasted through runoff and evaporation.

H. Discuss the importance of water quality

considerations; Water Quality Considerations:

Use irrigation water that is free of suspended matter or particles.

Sand, algae, and other suspended matter disrupt the smooth flow of water through an irrigation or sprinkler system and clog sprinkler heads and nozzles.

Use filters to screen particles before they pass into the irrigation system.

Use irrigation water that is free of suspended matter or particles.

Sand, algae, and other suspended matter disrupt the smooth flow of water through an irrigation or sprinkler system and clog sprinkler heads and nozzles.

Use filters to screen particles before they pass into the irrigation system.

Chlorine and fluoride added to city water for health reasons usually isn’t present in high enough levels to affect landscape plants.

Water quality varies from one location to another. In some cases, mineral content is so high that it affects

plant growth. Have water tested if problems occur.

I. Place pots 4 pots of soil from highest moisture content to lowest moisture content; and

Place the Soil: Students will test 4 different pots of soil that have different levels of moisture using the techniques stated in the PowerPoint. The students are to place the pots in order of highest moisture to lowest moisture.

J. Demonstrate how to water using a water hose and a

bucket.

PPT Slide 50-51 What should you consider about water quality?

Put it into Practice: Students are to practice watering with both a water hose and a bucket. Students will go through the practices of testing the soil moisture afterwards to see if the soil was watered in a uniform manner.

Review & Instruction:

Students will be tested using both written and demonstration methods. 50 points of the test will be

from a written test, and 50 points of the test will be demonstration. During the demonstration portion,

students will do similar activities that they have already done. Students will place 4 pots of soil in order

of highest moisture to lowest moisture. Students will then demonstrate how to water with a water hose

and how to water with a bucket.

Instructional Support:

A. References

a. IMS Online Curriculum

B. Teaching Aids & Equipment:

a. Water Landscape PPT

b. Watering Landscape Student PPT

c. Pots of soil with different moisture levels

d. Water hose

e. Bucket of water

f. Watering Landscape Test Review

g. Watering Landscape Test

C. Facilities:

a. Agriculture classroom