How to Grow a Healthy, Happy Florida-Friendly Lawn Laurie E. Trenholm, Ph.D.

Transcription

1 How to Grow a Healthy, Happy Florida-Friendly Lawn Laurie E. Trenholm, Ph.D.

2 Edited for Miami-Dade County By Adrian Hunsberger

3 Our Florida Lawn Grasses

4 Centipedegrass Poor man s grass very low input Watch your fertilizer- too much leads to decline Few insect and disease problems Light green color Slow growing and prostrate New cultivar Hammock developed primarily for use in south FL

5 Hammock Centipedegrass Reported to have deeper green color Adapted to climates and soils of south Florida All centipedegrass will dormant from cold or drought

6 St. Augustinegrass (Stenotaphrum secundatum)

7 St. Augustinegrass Best shade tolerance of warm-season grasses, but varies by cultivar Good salt tolerance Tolerates wide range of soil ph Establishes quickly from sod Deep green color Requires irrigation part of the year to stay green and healthy Chinch bugs becoming resistant to pesticides

8 St. Augustinegrass Cultivars Floratam most popular, poorer shade tolerance (needs min 6 hrs direct sun), chinch bugs the major insect pest. Do NOT use the herbicide atrazine. Bitterblue dark blue-green, chinch bug and gray leaf spot problems Palmetto semidwarf, tolerates some shade, lighter green than others. Chinch bugs and disease.

9 Dwarf St. Augustinegrass Captiva Dark green, slower-grower, tolerant to chinch bugs. Brown patch problems. Thatch. Delmar Good shade tolerance. Susceptible to insects and brown patch. Thatch. Seville Fine-leaf, dark green, shade is ok. Chinch bugs. Thatch.

10 Empire Zoysiagrass Low-growing, dense Very responsive to nitrogen Shade tolerance similar to Floratam Slower growth than St. Augustinegrass faster than old zoysias Susceptible to brown patch Tends to get thatchy Nematode tolerance?

11 Empire Zoysiagrass

12 Planting a new lawn

13 Can Turf and the Environment Co-exist?

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15 Green Industries Best Management Practices Educational program to reduce nonpoint source pollution Required for commercial fertilizer applicators in many counties and by state law by 2014 Partnership between FDEP and UF- IFAS

16 Non-point Source Pollution Pollution that comes from diverse sources that can t be pointed at

17 Turfgrass Fertilizer BMPs Keep fertilizer off impervious surfaces Maintain a buffer zone around water bodies Apply only the correct amount Low phosphorus! Only fertilize during the growing season Irrigate fertilizer in with about ¼ of water Do not apply fertilizer to impervious surfaces

18 Is This Where We Want Fertilizer? There is no place for this fertilizer to go but down the storm drain Does not matter if nitrogen is in quick or slow release form if it is left on impervious surfaces

19 Elements Required for Turfgrass Growth From Environment: Carbon Hydrogen Oxygen Macronutrients: Nitrogen Phosphorus Potassium Calcium Magnesium Sulfur Micronutrients: Iron Manganese Boron Copper Molybdenum Zinc Nickel

20 Why Fertilize? Lawns need nutrients to grow in a healthy condition Grasses grow and turn green in response to fertilizer A properly fertilized lawn is your best defense against weeds A properly fertilized lawn is your best protection against storm water runoff This does not mean overfertilization!

21 When to Fertilize? 2-6 times a year: Spring when growth begins Summer apply iron or low amounts of nitrogen fertilizer fertilizer important during times of growth Fall potassium beneficial Winter- Less N needed due to reduced growth but is needed to keep grass green South Florida may fertilize year-round

22 What Fertilizer to Use? Quick release nitrogen sources Often used by professional lawn care services and on athletic turf Very effective fertilizer Provides quick green-up and growth surge Effects generally not seen for more than 30 days or so Can leach if over-applied or followed by excess irrigation or rainfall

23 What Fertilizer to Use? Slow release nitrogen sources Release some nitrogen right away and some slowly over time Release rate tied to technology Response may range from days Less growth surge and green-up after application Sometimes homeowners get discouraged and re-apply when they don t see response

24 What About Other Nutrients? In high ph soils, iron & manganese may be limiting- these should be applied in a chelate or soluble form (not oxide form)

25 How Do We Apply the Correct Amount of Fertilizer?

26 Figuring out square footage of your lawn

27 Fertilizer Calculations Assume with 50% slow-release N How much N do we want to apply per 1,000 square feet with this product? 1 lb of slow-release N

28 Fertilizer Calculations How much 15% N fertilizer will supply the correct amount to this size yard? Divide 100 by the percent N in the fertilizer: 100/15 = 6.66 this is how many lbs of fertilizer to cover 1,000 square feet at 1 lb N 1,000 ft -2

29 Fertilizer Calculations - 27% N 27% N (30% Slow-release) 1 lb 1,000 ft /27 = 3.7 lbs of this fertilizer to cover 1,000 ft -2

30 So, What is a Good Fertilizer? Many options! Look for something with some of the N in slow release form Ratio of N to P must be at least 4:1 Eg x does not comply with DACS Labeling Rule Equal or close to equal K to N Low Ca and Mg (these compete with K for uptake) Micros in small amounts if soil test indicates In high ph, Fe and Mn should be available

31 Current UF/IFAS Fertility Recommendations (lbs. N 1000 ft -2 yr -1 ) St. Augustinegrass: North FL: 2-4 Central FL: 2-5 South FL: 4-6

32 Current UF/IFAS Fertility Recommendations (lbs. N 1000 ft -2 yr -1 ) Zoysiagrass (Empire): North FL: 2-3 Central FL: 2-4 South FL: 2-4

33 It s raining out- should we leave the sprinklers on? An efficient watering program must include: How frequently to water how much to water time of day to water

34 How Frequently to Water Varies due to: Season Soil type Shade Rooting depth Insect or other pests Other stresses

35 Irrigation Frequency Watch grass for signs of stress Follow watering restrictions! You may water hot spots with hose if needed

36 How Much to Water? Do not water past point of runoff this only wastes water. Apply 1/2 to 3/4 when turf shows symptoms of wilt This should not vary- only frequency varies!

37 Short, frequent irrigations Longer, less frequent irrigations

38 Irrigation System Efficiency Calibrate systems to ensure uniform coverage Check for broken heads, etc Check for landscape plants that may block sprinkler from reaching grass

39 Time Line for Irrigation for New Sod Plantings Time Frequency Duration First 7-10 days 2-3 times daily 7-10 days after planting Once a day Next 7-10 days Every other day Short (5-10 mins) try to keep plant material from drying out Apply ~ ¼ water more will be wasted due to short roots Apply ~1/4 to ½ of water 3-4 weeks after planting 1-2 times weekly Apply ~ ½ water

40 Irrigation System Efficiency One of the most important things to do during a drought is to check the efficiency of your irrigation system

41 Which Grass Has Better Drought Tolerance? All of our grasses need water to stay green (about the same amount!) Survival often depends more on soil organic matter, shade, rooting depth than species

42 I guess if your lawn looks like this, it doesn t matter..

43 But If You Do Want to Mow Correctly: Mow at the correct height for the species Mowing too low stresses the grass and forces it to use up all saved reserves for shoot growth Mowing high increased root depth

44 Mowing Heights St. Augustinegrass Standard Height Cultivars: Floratam, Bitterblue, Classic, etc St. Augustinegrass Dwarf Cultivars: Captiva, Delmar, Seville Zoysiagrass: ~2

45 Mowing Only remove 1/3 of the leaf blade at any one time Grass at 6 should have no more than 2 removed Make sure mower blades are sharp Do not mow wet grass Wash mower off afterwards

46 Scalping is a Major Stress

47 Leave the clippings on the lawn!

48 200 linear feet X 5 feet wide mower = 1,000 ft2 2,000 grams clippings (dry weight) 3.5% nitrogen in the clippings = 70 grams nitrogen = 0.15 lbs nitrogen

49 Thatch The dead leaves still attached to the plant. Does not break down. Is NOT grass clippings Dwarf varieties of St. Augustinegrass are prone to this. Major cause: overwatering and overfertilization. Hard to fix once you have it.

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51 How Do I Manage Turf in the Shade? Remove shade sources (trim trees) Reduce traffic in shaded areas Increase mowing height if possible more shoot tissue for photosynthesis will help turf perform better Reduce irrigation in shaded areas Reduce fertilization trying to promote shoot growth with high fertility will further stress the grass

52 St. Augustinegrass Shade Tolerance Seville, Delmar, Captiva Bitterblue Palmetto Floratam

53 EDIS Publications That Support Florida Friendly Landscaping Frequently Asked Questions about Florida Friendly Landscaping Frequently Asked Questions about Florida Friendly Fertilizing Frequently Asked Questions about Florida Friendly Irrigation wq142