Recovering the Flooded Landscape
Tennessee Master Gardeners
Ashland City
Courtesy of Ashland City Times
Kingston Springs
Courtesy of Ashland City Times
Residence
Courtesy of Ashland City Times
Welcome to Ashland City
Courtesy of Ashland City Times
First Things First:
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Be aware of personal safety (downed power lines,
sewage-contaminated water, displaced wildlife)
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Attend to your damaged home
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Document damage and report to insurance company,
TEMA/FEMA
The Clean Up:
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Is the site dry enough to enter?
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Thick silt will cover the landscape & may have a raw
sewage-like odor
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Caused by lack of oxygen in the soil
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When dry, remove trash, debris & uprooted plants
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Separate home trash from yard waste—place in
designated place for pick up
Your Landscape May Recover!:
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Established plants have a good chance of survival
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Many plants will look dead, but don’t pull them out unless
physically damage is major
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Known to survive after 2 weeks under water:
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Native trees
Native shrubs
Native perennials
Hardy bulbs
Plants at Risk (don’t like “wet feet”):
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Japanese Holly
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Japanese Boxwood
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Indian Hawthorn
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Nandina
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Hybrid Junipers
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Hybrid Azaleas
Encore Azalea
Plants Most Likely to Survive:
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Crape Myrtles
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Chinese Holly
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Casissa Holly
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Burford Holly
Burford Holly & Crape
Myrtles 3 months after flood
Plants Most Likely to Survive:
Crape Myrtle
Chinese Holly
Deciduous & Evergreen Plants:

Most deciduous plants will defoliate immediately after a flood
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Before pruning, wait to see if bare branches bud out in next
month or two

Hardy evergreens (like Chinese Hollies) may hold their leaves

Washing the silt off evergreens will aid their survival (do not
pressure wash)

Cover any exposed roots
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Apply fresh mulch (never use fresh hardwood mulch)
Trees:

Remove excess silt and soil from trunks and crowns

Cover any exposed roots
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Remove broken or damaged limbs
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Wait to see if bare branches start to bud out in next month or two
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Apply fresh mulch (never use fresh hardwood mulch)

Trees may experience a forced dormancy due to flood shock
& lack of soil oxygen

Leaves will turn yellow & drop off, and some branch die-back may
occur
Trees:

Trees may experience a forced dormancy due to flood
shock & lack of soil oxygen

Leaves will turn yellow & drop off, and some branch die-back
may occur
Anticipate:

Plants will be stressed
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Wet soils encourage root and crown diseases (fungi)
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Fusarium spp.
Phytopthora spp.
Pythium spp.
Rhizocotonia solani
Improve site drainage
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Poor growth
More diseases
Helps reduce stress and disease
Replace lost soils with organic matter
Nutrients:
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Avoid excessive nutrients during recovery
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High nitrogen fertilizers are not beneficial to trees & shrubs at
this time

Excessive fertilization can increase diseases

Take a soil sample to determine needs

Organic matter replaces lost soil microbes as well as
slow-release nutrients
Your Flooded Garden:
Gardens:

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Food Safety!!
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Flood waters are contaminated with raw sewage

Handle with caution
Eating leafy or bulb/root vegetables should be avoided
Spinach or lettuce
Garlic, onions, radishes
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Some vegetables are less risky if they can be boiled
Turnips

Visit http://foodsafety.gov for more information on food
preparation & safety
Newly Seeded Gardens:
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Most did not survive the flood, or were washed away
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The good news? We have much of the growing season
left to start over

Let soil dry out completely--working wet soils leads to
large dirt clods and future soil compaction
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Add amendments, composted organic matter, straw and
mulch
Flooded Turfgrass:
Golf Course
Athletic Field—after flood
Turf & Lawn Areas:
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Most resilient to flooding:
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Bermuda grass
Bahia grass
Hybrids of the above
Bermuda grass, under 4 weeks of floodwater, has
responded with re-growth after drying out
First, remove sediment, silt, organic debris
Mow, removing only 1/3 of height
Apply 1/2 lb. of nitrogen per 1,000 sf – will encourage turf
recovery
Follow normal maintenance practices
Sprinkler Systems:

Turn off power & inspect electrical systems

Replace irrigation clock if it was flooded
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Have backflow prevention system inspected by a
professional

Shut off water supply, open drain valve, drain water from
underground pipes
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Rotors—remove, shake out, & rinse
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Flush the pipe system before replacing the heads
Sprinkler Systems (cont):

Open valves one at a time to full open position & turn
system on manually
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Run water for 5 minutes at each zone
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Reinstall heads & run system for 10 minutes
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Turn off water & be sure all heads retract
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Replace heads not working properly
Patience
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Salvaging a flooded landscape can be economically feasible
if you have the time & patience
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Let your plants return naturally
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Replant with native species
Nature’s resilience will amaze you
Websites for Additional Information:
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http://www.extension.org/pages/Recovering_the_Flooded
_Landscape
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http://utextension.tennessee.edu/Pages/default.aspx
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http://fcs.tennessee.edu/nutrfdsfty/safefd/index.htm
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Facebook: Tennessee Master Gardener page
Thank You
Nancy Coop, Cheatham County MG