Plant Water Use

Soil Water Holding Capacity

Watering Systems

Reducing Water Use in a Drought

Waterwise Landscaping or Xeriscape

Laundry to Landscape Greywater & Rainwater Harvesting

http://cagardenweb.ucanr.edu/

Meet the PLANT’s needs

Water moves from roots to shoots (high to low potential)

Transpiration - water exits the leaves through stomata

ET = Evaporation + Transpiration

When a plant is water stressed, it closes stomata & photosynthesis slows

Repeated wilting causes damage

Some plants are better at conserving water………..

Thick, waxy leaves that store water (succulent)

Grey, silvery leaves that reflect light

Small or needle-like leaves

Hairy leaves slow air flow, reducing evaporation

Strong structure that minimizes damage due to wilting

Recognize signs of drought stress Lawns

Retain a footprint for several minutes, brittle

Wilted & bluish gray leaves

Wilting or drooping leaves that do not return to normal by evening

New leaves that are smaller than normal

Grayish, lusterless foliage

Curled or yellow leaves that fold or drop

Water movement in soil

Remember soil lecture?

Clay holds 4X more water than sand, but not always good.

Add organic matter!

Practice moisture testing

Use soil moisture meter or tensiometer (maybe)

Just dig a hole with a trowel at root level and test for moisture with your hand

Veggies, flowers & turf – root zone 6” to 1’

Don’t water groundwater or atmosphere

Watering Systems Automatic sprinklers

Hose end sprinklers

Furrow irrigation

Drip irrigation

i.e. RainDrip w/emitters

DripWorks w/t-tape

Microspray

Soaker hose

Basin irrigation

Hand watering

For Lawns using Overhead Sprinklers

Set out pattern of cans (tuna?)

Turn volume on at set amount (i.e. 1 ½ turns) for hose bib

Run for 20 minutes

Measure water depth in cans

Multiply times 3 to get inches per hour (output)

Compare variability within cans – try to achieve less than 15%

Measure application rate and uniformity

Determining irrigation needs for lawns

Use tables in MG Handbook or Lawn Watering Guide to determine inches per week

Apply volume based on your “can” test in multiple applications

Avoid runoff or puddling

Try timers

Don’t wet tree trunks

Furrow Irrigation Rare in Trinity

Difficult on slopes, need level ground or cross-slope

Drip Irrigation for landscapes, etc

Frequent, slow application to root system

Not all “drip” systems are low volume, which needs pressure reducer down to 10-20 psi

Lower water use, less disease, runoff & groundwater contamination

Soil dries out between irrigation

Drip Irrigation Layout

Drip Irrigation Hints & Cautions Adjust timing spring vs summer

Different manufacturers are not compatible

Use pressure compensating for slopes

Can clog Need filter for surface water, well water

with clay or highly mineralized water

If buried or unmaintained (subsurface), roots intrude or deposits form

Spinner type sprinklers have moving parts that wear out, but spray water further

Supplemental irrigation for germination

Convert sprinkler heads to drip

Irrigating Trees

•Different timer •Calculate water volume needed •Don’t spray trunks

Irrigation of Gardens & Landscape Beds

• Low Volume works well

• Match delivery system to plant

• Drip tape (rows)

• Emitters (individual plants)

• Soaker hose or drip tube (curving row)

• Hand water (container)

• Basin (fruit tree)

Water Conservation for Vegetable Garden

Shorter season crops

Fewer crops

Plant in blocks & vertically

Group plants into zones

Control weeds (don’t water weeds!)

Add organic matter

Mulch!

Irrigation of Fruit Trees • Semi-dwarf trees can use 16

gallons per day during peak heat

• Mulch & eliminate lawn & weeds

• Don’t deficit water early in season

• Check soil moisture

• Measure water applied

• Drought : Try to wet 60% of area that roots will explore

• Don’t water when no leaves

Use double ring tree watering basin

Irrigation Needs of Fruit Trees

Table 16.4 of Handbook

70-100% of ET for good yields

Hot Midsummer Day

1 yr (4 sf) – .6 gal/day

4 yr (100 sf) – 16 gal/day

Standard (300 sf) – 47 gal/day

Deficit watering of fruit trees

Early season water (during bud break, flowering & fruit set) is important

Can decrease watering til fruit is half grown, fruit will catch up when irrigation starts again

Remove ground cover & add mulch to decrease competition for water

Don’t underirrigate young trees

Thin heavier than you usually do

Expect lower production next year

Can post-harvest irrigate, but not when dormant

Irrigation Best Mgmt Practices Create hydrozones (group plants)

Apply the right amount of water

Water deeply & infrequently (but not too deep)

Veggies, flowers & turf – 6” to 1’

Overhead water early in the morning, drip anytime

Irrigation at night reduces water used by 5-7%, but you have to remember to turn it OFF. Timer!

Avoid deep percolation & runoff

Apply water uniformly

Mulch, amend soils with organics, regular maintenance

Planning/Design

Prepare your Soil

Mulching

Minimize turf areas

Plant Zoning

Efficient irrigation

Proper maintenance

7 Basic Principles of Waterwise Landscaping

1-Planning Evaluate your needs

Huge lawn or just children’s play area?

Entertaining? Foot traffic?

Block view of neighbor?

Environmental conditions

Sun, shade, wind, slope, drainage pattern

Make appropriate plant selection for the climate where you live

Mediterranean climate plants are suited to much of California (Cool wet winters, dry

hot summers)

Consider appropriate native plants

2-Prepare your Soil

Amend with Organics!

Remember what we talked about in

Soils – organics increase ability to

hold moisture

3-Mulching A 2-4” layer of organic

mulch can provide many

benefits: water retention,

weed reduction, erosion

control.

Shredded bark, grass

clippings, and compost

are organic mulches

Inorganic mulches include

stone, cloth and plastic.

Pine needles

Pine bark

Proper way to mulch a tree

Organic Mulches

4- Minimize Turf Areas Lawns require large

amounts of water,

fertilizers, money and

time.

Plant only as much as you

need

Plant the appropriate type

of turfgrass for your

climate.

Hardscapes, mulches and

rocks.

✔ Use turf effectively for function rather than appearance only.

✔ Consider substituting ground covers or natural mulches.

✔ Remove lawn one area at a time.

What if I want to get rid of my lawn right now?

Try sheet mulching

Mow as low as you can

Layer of organic material like cardboard, newspapers, or jute floor covering

Cover with 4-5” of mulch & compost

Can cut holes and plant through it later

Rent a turf cutter

Herbicide

BUT – wait til fall to plant landscaping due to initial water needs

• Limit area of annual flower beds

• Use containerized plants

5 - Zoning

Group plants according to the same exposure and water needs

i.e. Sunny, well-drained & moderate water need vs shady & moderate water

Don’t put fruit trees in lawn (or have separate irrigation)

Group low water users that may only need supplemental irrigation in summer.

6- Efficient Irrigation

Zone irrigation systems to match plant requirements Separate irrigation lines can be programmed to meet differences in frequency and duration

Use drip lines and soaker hoses

Irrigate shortly before sunrise. Avoid irrigation during windy periods.

Install permanent, automated irrigation system. Design irrigation systems to emphasize uniformity especially on turf areas

Sprinkler calibration ~ three to four times a year Water use rates vary greatly from season to season

Avoid overspray from sprinklers onto sidewalks, patios or other areas.

Refrain from watering during the winter

Check irrigation system and repair regularly

Mow lawn areas to a height of 3”.

Remove about 1” of grass each

time you mow

Heavy pruning & fertilization

stimulates growth, which

increases water use

Eliminate weeds

7- Proper Maintenance

Household Water Use in California

What is “Greywater” Water from washing machines, showers, bathtubs, bathroom sinks.

Does NOT include water from toilets, kitchen sinks, dishwashers or wash water from diapers.

Greywater Options

Since 2009, can install a washing machine only system without a permit

Need a permit from Building Dept to install a greywater system that

Collects water from showers, sinks or baths

Includes a pump

Or cuts into the plumbing

Laundry to Landscape

•Uses washing machine pump to distribute water •1” PVC tubing •Max 50’ length •Water distinct plants deeply, then move on

Greywater constraints Can contain pathogens

Don’t store for more than 24 hours

Don’t use for irrigating contact food crops

Subsurface disposal to minimize contact (i.e. under mulch)

Don’t allow ponding

Greywater Laundry Detergent Mainstream detergents

are not OK, since they contain salts

Use diverter valve if using detergents or additives

Use intermittent with other irrigation

Liquid is better than powder

Rainwater Harvesting Metal & composite shingle roofs are most efficient

Multiply annual rainfall (in) X roof area (SF) X .623 gallons

1000 SF roof, 40” of rainfall = 25,000 gallons

Rain Harvesting Considerations Less feasible in our

climate

Not potable!

Contains pathogens, metals, contaminants

Use for drip irrigation, not overhead

May need sand filter for composite shingles

Rainwater Harvesting Design First Flush Filtration

Overflow & strainer basket with screen to prevent mosquitoes

Dark colored tank w/ UV inhibitor to prevent algae growth

Cleanout

Pump? Or low flow irrigation downhill

Young Family Ranch #1 1000 square foot roof,

collect 1” rainfall = 623 gallons

500 gallon tank with hose bib at bottom

Use to gravity irrigate fruit trees (low pressure with bubble sprinkler)

Young Family Ranch #2

1000 square foot roof, collect 25” rainfall = 15,000 gallons

Collection tank with pump to uphill tanks

Use to gravity irrigate lawn & vegetable garden

Carol’s Rainwater Harvesting Gutters drain 700 sf of my

roof, takes ¾” of rain to fill tank

My tank is 330 gallons ($300)

Used bucket to transfer water in 2014, now have transfer pump

My flower garden gets 15 gallons per week

1 tank of water lasts for 1 summer

Creative Water Recycling

Wash vegetables in your garden (if potable water)

Take a shower in your garden (soap & shampoo are OK)

Capture sink water to irrigate potted plants

Wash car on lawn