Janet Hartin Environmental Horticulturist. Keeping Plants Alive Under Drought and Water Restrictions in the Coachella Valley

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1 Janet Hartin Environmental Horticulturist Keeping Plants Alive Under Drought and Water Restrictions in the Coachella Valley

2 Sustainability meeting the needs of today s population without diminishing the ability of future populations to meet their needs.

3 Why Garden Sustainably? Save Money Improve Garden Health Protect Water Quality and Wildlife

4 Sustainable Landscaping Leaves a greener footprint for our children s children

5 Sustainable Landscapes Incorporate plants suitable for climate/location Conserve water Nurture and protect soil Prevent/reduce pest problems Conserve energy/reduce pollution Encourage wildlife

6 Select plants recommended for your Sunset Zone

7 And Microclimate

8 USDA Zone 9 (Not As Specific As Sunset Zones)

9 Sunset Zones Are Smaller and More Accurate Riverside County Includes Zones 13 (desert) and 18 and 19 (valley cities)

10 Let s Look at Drought Efficient Examples for Sunset Zone 13 (Coachella Valley)

11 Acacia pravissima (small tree) - Yellow flowers - Attract birds - Fast growing

12 Tolerates heat and drought but also irrigation seepage from nearby lawns Bark and foliage nice contrast Acacia rigidula Blackbrush acacia (Shrub or small tree)

13 Grevillea Canberra Gem (shrub or small tree) Bright red flowers In spring Relatively disease and insect resistant

14 Parkinsonia hybrid Desert Museum (Palo Verde) Excellent thornless, sturdy specimen tree Grows to 30 Deep yellow flowers

15 Fremontodendron californicum (shrub or small tree) Yellow flowers in spring Fast growing Glossy green foliage

16 Acacia redolens Prostrata Prostrate Acacia (groundcover) Grows to 1 2 tall, spreading Rapid coverage for slopes Great for erosion control

17 Wedelia trilobata Yellow Dot (Groundcover) Rapid spreading to 1 1/2 high and 6 wide Dark green leaves accentuate yellow flowers in summer Takes some shade

18 Shade, wind, poor soil, power lines, etc.

19 Sustainable Landscapes Conserve Water Through: 1. Hydrozoning 2. Scheduling irrigations based on plant needs 3. Making sure sprinklers/drip systems work properly 4. Using mulch and soil amendments effectively

20 Hydrozoning: Placing plants with similar water needs in the same irrigation zone

21 Plant Water Use Varies Among Species Influenced By Climate and Microclimate (as previously discussed) Varies by Density of Planting

22 Adjusting your irrigation timer seasonally can save a lot of water and keep plants healthy! ( Smart controllers are only as smart as the dummy who programmed them.)

23 Monthly Reference Evapotranspiration (ETo) (water used by cool season turfgrass) 12 Palm Springs Reference Evapotranspiration (in./mon) Riverside San Francisco 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month

24 Maximum Applied Water Allowance (MAWA) = (ETo) (0.7) (LA) (0.62) ETo = Reference Evapotranspiration (inches per year) 0.7 = ET Adjustment Factor LA = Landscaped Area (square feet) 0.62 = Conversion factor (to gallons) *Maximum Applied Water Allowance = gallons/year Example of Maximum Applied Water Allowance (MAWA): Hypothetical Landscape Area = 5,000 sq ft MAWA = (Eto) (0.7)* (LA) (0.62)** MAWA = (71.5) (0.7) (5,000 sq ft) (0.62) MAWA = 155,155 gallons per year *ET Adjustment Factor ** Conversion factor from inches to gallons

25 High water using plants use as much water as cool season grass. Medium water using plants use about 30 percent less. Low water using plants (drought tolerant) use percent less.

26 Low, Medium and High Water Use Hydrozones

27 Drought Efficient Landscape (requires regular water until established (first season) then cut back

28 Consult these Resources for Help Determining Irrigation Needs of a Wide Range of Plants: Water Use Collection (UCD) Local Water Districts Living Desert/Wellness Park, etc. Park

29 Water Needs of the Same Species are Higher in Heat Islands Landscape plants in heat islands require up to 50% more water than the same species in a park setting

30 The Denser The Planting, the More Water it Needs Examples of Dense landscapes

31 Examples of Low Density Landscapes Requiring Less Water than Denser Ones

32 Water an inch or Two Below the Current Root Zone to Draw Roots Down Avoid runoff (common in heavy clay soils) Avoid losing water below the root zone (common in sandier soils)

33 Irrigate Established Plants Less Often But Deeper Than Newly Planted Ones (Most overwatering occurs in established landscapes while most underwatering occurs in newly planted landscapes)

34 Monitor Soil Moisture with a Probe, Trowel, or Straightened Metal Coat Hanger

35 Drip systems apply water directly into root zones, reducing soil evaporation. They are recommended for non turf/groundcover plantings.

36 Irrigate outward in the root zone of the plant (left). Incorrect (right). Keep plant crown dry.

37 Sprinkler systems are recommended for irrigating turf and groundcovers but need to be checked regularly for problems such as: Broken heads Sunken heads Non vertical heads Wrong spacing

38 Irrigation system wastes more water than the lawn

39 Warm Season Lawns (Bermuda, Buffalo) Use Less Water than Cool season Lawns (Tall Fescue, Rye) Lawn Watering Guide for California

40 Misleading advertising cool season grass uses 25 percent or more water than warm season grass and neither are low maintenance.

41 If you have a lawn, grasscycle or compost clippings! Saves time/money Adds organic matter to lawn Recycles nutrients Reduces greenwaste in landfills

42 Water cycling may be necessary to avoid run off when using sprinklers. Divide the total amount of water required per day into 2 4 cycles applied closely together before soil dries out.

43 If you re no longer using and enjoying your lawn, consider replacing it with a lower maintenance, drought tolerant alternative.

44 Turf is a poor choice in small and oddly shaped areas and on slopes!

45 Consider replacing turf with low maintenance drought efficient alternative groundcovers

46 Acacia redolens Desert Carpet

47 Baccharis Centennial

48 Dalea greggii

49 Other Methods to Conserve Water in the Landscape

50 Minimize the use of water to clean sidewalks and driveways

51 Remove weeds that compete with landscape plants for water

52 Improve waterholding capacity and/or drainage with compost mixed evenly into soil (6 1 deep)

53 Don t Let Water Get Away! Permeable surfaces Infiltration Basins Water Collection

54 Consider Recycling Graywater ( laundry to landscape systems) on non edibles

55 Apply Mulch Around Plants

56 Mulch Conserves Water and Beautifies Landscapes

57 Keep mulch several inches away from tree trunks and avoid volcanoes!

58

59 Avoid Over fertilizing (non edibles need very little) Creates flushes of weak growth Increases water requirement Leads to waterway pollution

60 Runoff contributes to pesticide and nitrate/phosphate pollution in our waterways

61 Following are Suggested Methods To Maintain Various Landscape Plants During Water Restrictions and Severe Drought

62 Trees and Shrubs (prioritize them over flowers/lawns) One or two deep irrigations with a garden hose several weeks apart in spring and summer will often keep these valued plants alive through summer

63 Fruit and Nut Trees Keeping them alive and producing fruit may not be possible. To produce a good crop, deciduous fruit and nut trees need adequate water in their root zones continuously from bloom until harvest.

64 Vegetables Vegetables are difficult to maintain during a drought. Water is most critical from seedling stage through root establishment and during flowering and fruiting.

65 (Con d) Tomatoes, beans, and root crops such as carrots require regular watering and are not drought tolerant. Vine crops such as squash and zucchini often fare better and can be kept alive with a few waterings once or twice a week through the season.

66 Groundcovers Groundcovers often survive on about half the amount of water received under optimal conditions. To avoid serious drought stress non-native thirsty groundcovers need irrigation monthly spring through fall. Yellow Dot

67 Lawns (maybe it s time to switch?) Traditional warm-season lawns (bermuda and buffalograss) are more drought-resistant than cool season grasses (ryes and tall fescues) and may come back after several weeks of dryness. Reduce irrigation to ½ of recommendations in the UC lawn watering guide (

68 Thank you! Janet Hartin Phone: (951)

69 Coachella Valley MG Helpline: Ph: (760)