2015 – 2016 Articles
April 2016
Ligum vitae
Guaiacum sanctum (or Guajacum santum)
Holywood,, tree-of-life
Have you been fortunate enough to have seen a Lignum
vitae in full bloom? It is spectacular.
This wonderful tree was almost logged to extinction due to
its dense wood and resins. The wood was used for
shipbuilding as it is self-lubricating. One of the hardest of
woods (it is so dense, it will sink in water) it has been made
into bearings, gears, pulleys, mallets, propeller shafts and
even bowling balls. Medicinally, it has been used in the
treatment of arthritis, gout, syphilis and more.
It is listed as endangered by the state of Florida.
Not only beautiful, it is a source of nectar for pollinators and the larval host plant for the Lyside Sulphur
butterfly. Birds, such as catbirds and mockingbirds eat the seeds. It is the National tree of the Bahamas.
The tree is long lived; carbon dating suggests it can live 1000 years. A slow grower but so worth the
wait!
March 2016
Hmm, good question!
How do you treat a whole garden for iron chlorosis with chelated iron – I don’t have time!
The first thing to ask yourself is, do you need to? Treatment needs to be applied only to those plants that are
showing signs of iron deficiency. If you are like most of us and have many, many plants that might need
treatment, providing a drench treatment might be time prohibitive. An option is to use a foliar spray.
A foliar spray can provide a quick response but be mindful that it is temporary; the treatment will have to be
repeated several times each season. A water soluble fertilizer that includes iron sulfate or a chelated iron can
be found at big box stores; most common are Miracle-Gro or Jack’s 20-20-20 Classic All-Purpose Fertilizer
(formerly known as Peter’s). If you want just an iron supplement, the less expensive chelate, EDTA chelate,
can be used. This product can be found at Amazon.
It is crucial that direction for foliar spray use is followed. If just enough is good, more must be better, right?
WRONG; too concentrated a dilution can cause leaf burn. Spray late in the day to avoid high temperature and
avoid evaporation; the longer on the leaf, the more absorption of supplement. (Chelated iron sprays can be
inactivated by sunlight, as well). All leaves must be treated for complete greening.
What a great question. Finding answers (search engines are great) is how we all learn (me, for example).
February 2016
Neonicotinoids; what are they?
Neonicotinoids are manufactured pesticides that mimic the natural insecticide nicotine. They act on the
insect’s central nervous system. The neonicotinoid pesticides are water soluble and can be applied by
spraying the leaves or as a soil drench, which the plant’s vascular system then distributes through all
parts of the plant. Decision of which application method to use is important due to the possible effects
on both good and bad insects.
Insects particularly affected are sucking insects and chewing insects. This includes such insects as:
aphids, mealybugs, scales, whiteflies, psyllids, leafhoppers, beetles, ants, leafminers, and thrips. Sounds
great, huh? But ….. be mindful that beneficial insects can also be harmed. The harm can be minimized,
dependent on method and time of application, if it is determined the pesticide must be used. Birds and
mammals are typically not adversely affected by neonicotinoids.
Type of application dictates length of effectiveness. A systemic drench will be effective for 9 to 12
months while foliar treatment lasts for 3 to 6 weeks. Plants bought at big box stores are likely pretreated with neonicotinoids by systemic drench.
So, what can the home gardener do?


If the concern is for pest insect damage to the plant only, the application best suited would be
the soil drench. This is used often on larger plants and trees.
If there is concern for beneficial insects, such as bees and butterflies, the best option would be
the use of foliar spray.
o With any pesticide, follow the label directions carefully.
o Apply either early in the morning or in the evening, when bees are not foraging
o Treat only affected plants.
o Remove blossoms
Bees will be affected by the blossoms only. Other insects, such as butterflies and moths, will
use both the leaves as larval food source and the blossoms as a nectar source.
Chemicals names to look for as active ingredients are: Acetamiprid, Clothianidin, Dinotefuran,
Imidacloprid, Nitenpyram, Thiocloprid, and Thiamethoxam. One of the most common (and the earliest
in the marketplace) is Imidacloprid, which is commonly found in the Bayer Advanced Garden
insecticides.
The Coontie at our local big box store has
been treated with nicotinoids, as has
many of their bedding plants. Be watchful
if you are interested in our beneficial
insects.
Some stores are phasing out this practice.
EPA is not allowing new product use until
further testing is completed. Products presently
on the market were approved, staritng in the 90’s.
January 2016
Some less harmful deterrents to mouth sucking pest insects are a sharp spray of water (aphids),
insecticidal
soap
(most
everything
but mature
scale) and horticultural oil.
Soil, what
soil? Do
you
have
soil? I don’t
have soil……….!
We surely have our difficulties gardening in the Keys. Heat, drought, and flood are only part of it. Our
soil, or lack of soil, affects all our gardening efforts. Why do we have little (or no) soil? Here is how our
Monroe County extension describes our local geology.
” The Keys are formed of two distinct substrates; both are types of limestone. The Upper Keys are
actually remnants of a coral reef which emerged from the sea about 100,000 years ago as ocean levels
dropped. This ancient coral reef formation is known as the Key Largo Limestone formation and extends
north into the mainland for some distance. This limestone is actually the calcium skeletons of coral and is
very porous, with large solution spaces. Therefore, rainwater drains quickly from the soil, but salt water
may also rise up into the soil. The Lower Keys are formed of a substance known as Miami limestone or
oolite. Oolite is a medium to hard limestone that forms in shallow, warm ocean waters. The higher
temperatures and higher evaporation in shallow waters raise the concentration of calcium carbonate
particles in the water, where over time they are packed into solid limestone rock. While porous stone,
water cannot move quite as freely as it does through the coral rock of the Upper Keys because the
solution spaces in oolite are smaller.”
Edited from UF/IFAS, Solutions for Your Life, Getting to Know the Keys, Geology,
by Jeannette Hobbs
So, yah, it’s limestone, but why isn’t there soil? Time, there hasn’t been enough time! 100,000 years just
counts as seconds in Mother Earth time. The Appalachia are an estimated 475 million years old (USGS).
The rock in Appalachia has had lots of time to break down to soil. In the Keys environment, rock breaks
down into smaller pieces due to the effects of rainfall, storms, wave action, and root intrusion. The
fragmented rock then mixes with organic materials; plant and creature detritus to create soil. Our high
temperatures do increase the rate of breakdown of rock. But……….it takes a long, long time! 100,000
years compared to 475 million – mere seconds.
…………………………………………………………………………………….
The leaves on my plant look funny; they’re lime green with dark green veins.
What’s going on? HMMMM! It’s chlorosis, caused by an iron deficiency! Guess I’ll go
buy some iron at a big box store!
Wrong!!!!!!
The soil in the Keys, mostly comprised of limestone, considered a calcareous soil, has a very high pH;
typically, 8.2 to 8.5. This means it is very “alkaline”. Iron naturally found in calcareous alkaline soil
oxidizes, precipitates out, is insoluble and often combines with other minerals; making the iron
inaccessible to plants.
Foliar iron sprays are helpful but only for the short term. A longer term fix is to use a granular additive.
But…………. the iron additives found in big box stores will also oxidize, precipitate out and so on. The
most effective option for our very alkaline soil is a granulated product called chelated iron. There are
several forms of chelation; the best for our soil is EDDHA iron, also known as Fe-EDDHA. (Chelates are
compounds that stabilize metal ions (in this case - iron) and protect them from oxidation and
precipitation). These products are soil drenches, which typically will feed the plant for a year. This
product is relatively expensive but is effective. It can be found at the MARC House Store.
*High pH also causes other mineral deficiencies. To treat, look for granular fertilizers that are slowrelease (water insoluble). Water soluble fertilizers will be washed out by our heavy rains or repeated
irrigation.
December 2015 Don’t forget our feathered friends!
We concentrate on attracting butterflies, but what about birds? Birds are an important part of our
ecosystem; they are pollinators, disperse seed (and fertilize at the same time), scavenge, create habitat
for other creatures, aerate soil, eat insects and act as environmental indicators. As important, they
satisfy the human soul, with color, shape, sound and motion; their flight inspires our imagination and
gives us a sense of freedom. Let us all value and care for our eathered friends.
Grow plants that provide food and shelter for our year round and for fly-bys, provide food and water;
they will come.
Native plants that attract birds.
Common name
Birds attracted to plants
Vines
Corkystem passionvine
Hummingbirds, fruit and insect-eating birds
Shrubs
Beautyberry
Cocoplum
Firebush
Necklace pod
Wild coffee
Mockingbirds, Cardinals, Catbirds, Thrashers, Vireos, Woodpeckers
Fruit-eating birds
Hummingbirds, Warblers
Hummingbirds, Warblers, Vireos
Cardinals, Blue jays, Catbirds
Trees
Blolly
Coffee colubrina
Dahoon holly
Figs
Florida privet
Gumbo limbo
Lamark's trema
Marlberry
Myrsine
Paradise tree
Pigeon plum
Sabal palm
Satinleaf
Seagrape
Silver palms
Simpson's stopper
Thatch palms
Fruit-eating birds
Warblers, Gnat-catchers, Vireos, Flycatchers
Cardinals, Mockingbirds, Wax wings
Mockingbirds, Catbirds, Thrashers, Blue jays, Wax wings, Woodpeckers
Warblers, Vireos
Doves, Mockingbirds, Vireos, Warblers, Woodpeckers
Fruit-eating birds
Mockingbirds, Catbirds, Crdinals, Fruit-eating birds
Cardinals, Jays, Thrashers, Woodpeckers, Fruit-eating birds
Fruit-eating birds
Mockingbirds, Catbirds, Robins, Woodpeckers
Blackbirds, Blue jays, Mockingbirds, Robins
Warblers, Cardinals, Blue-gray gnatcatchers
Mockingbirds, Catbirds, Blue jays, Woodpeckers, Fruit-eating birds
Mockingbirds, Blue jays
Mockingbirds, Catbirds, Cardinals
Fruit-eating songbirds
Audubon Society of the Everglades, Naturescape Broward, IRC, FL Keys NWR, S.Reutling
November 2015
I have had a teensy thought flitting through my mind; wait, flitting; what “flits”? Butterflies! Hmmm! I’ve
been thinking about Monarchs. We are all concerned about the decrease in numbers and thus seem to
obsess on the larval host plants, milkweeds. (With good reason; it is the primary larval host plant). But, I
think we should consider nectar plants that we can plant and that will provide the nutrition both for our
local Monarch population and our migrating Monarchs.
There are lots of nectar plants for us to add to our butterfly gardens, both native and non-native. Native
plants include Beach verbena, Blue porterweed, Buttonbush, Dune sunflower, Saltbush (Groundsel),
Seashore ageratum, Seaside goldenrod, Spanish needles, and Tickseed. Some of the non-native plants
are Coreopsis spp., Golden dewdrop, Goldenrod spp., Lantana spp., Milkweed spp., and Verbena spp.
Anecdotally, I’ve seen Monarchs feasting (and flitting) on the Seashore ageratum at the Key
West Botanical Garden. The ageratum is also a nectar source for the Cassius blues,
Common buckeye, Painted lady, Queen, Skippers and others. It is also a nectar source for
bees and is salt tolerant (thus the name Seashore). What’s not to love?
……………………………………………………………………………………………………….
(FANN information – introduced for information – no need to reinvent the wheel – not Susie’s)
Native vs. Non-native (some non-native species do not do well without special care!)
This picture shows an urban development that was abandoned for three years that contained the Florida
Native Sabal Palm and the non-native Queen Palm. As you can see, all the Sabal Palms remained strong
and healthy and the non-native Queen Palms...well....didn't. Yet we still see many homeowners planting
Queens and way too many local nurseries selling them. Queen Palms are not wind resistant, are prone to
various nutrient deficiencies and diseases and don't support pollinators or other wildlife. They can also
become invasive in our area and are already of the Florida Exotic Pest Plant Council's Category II "watch
list."
Credit Florida Association of Native Nurseries (FANN)
October 2015
Our native Coontie is a wonderful plant, being the larval host plant for the endangered Atala
butterfly and a food source for mockingbirds, blue jays, other birds and animals. The attractive
plants’ genetic brothers and sisters have been on earth since dinosaurs walked. After proper
processing to remove toxins, it was a food source for native Indians, early settlers and was even
sold as a commercial starch product, Florida arrowroot, until the practice was condemned by
the FDA in 1925. BUT, one of the toxins found in cycads is cycasin, a water soluble glucoside
which can affect the stomach, the liver, the nervous system, and is also carcinogenic. Be aware
of its effects on our pets and people, protect them, and always, always wash your hands well
after working with any Zamia.
………………………………………………………………………..
Deb mentioned our difficulties growing butterflyweed, Asclepias tuberosa. It appears that its range
extends south to Miami-Dade county and not into the Florida Keys. Institute for Regional Conservation,
Natives for Your Neighborhoods, considers Butterflyweed (Asclepias tuberosa), Fewflower milkweed
(Asclepias lanceolata), Green antelopehorn (Asclepias viridis), Swamp milkweed (Asclepias incarnate),
and Whorled milkweed (Asclepias verticillata) native to South Florida. But, the furthest range for all,
with the exception of Green antelopehorn, is Miami-Dade or Monroe County mainland. Green
antelopehorn is found in the Monroe County Keys in the pine rocklands of Big Pine Key, where it is
considered rare. I suspect that, with the exception of the introduced tropical milkweed, Asclepias
currasavica, our temperatures are just too warm (and getting warmer) for these mostly temperate
plants. I suspect they can be grown, but should be treated as an annual, to be replaced each year, and
not be treated as a perennial. Seed for these native milkweeds can be found at
www.prairiemoon.com/seeds/ .
Hardiness and Heat Zones
USDA Plant Hardiness Zone Map
We are all familiar with the
USDA Plant Hardiness map.
Here in Monroe County Keys
we are typically frost-free.
Just as important is our heat
zone. Too much heat can
adversely affect our plants
health and survivability.
AHS Heat Zone Map
Based on heat days – the number of days a year
the temperature is above 86 °F.
Zone 1 is 0 days
Zone 12 is 210 days
“The effects of heat damage are more subtle than
those of extreme cold, which will kill a plant instantly.
Heat damage can first appear in many different parts
of the plant: flower buds may wither, leaves may
droop or become more attractive to insects, chlorophyll
may disappear so that leaves appear white or brown, or
roots may cease growing. Plant death from heat is slow
and lingering. The plant may survive in a stunted or
chlorotic state for several years. When desiccation
reaches a high enough level, the enzymes that control
growth are deactivated and the plant dies.”
(American Horticultural Society)
Why does information about heat zones matter? With the seemingly increase of our temperatures we
are likely to see more temperate plants fail, either due to cell destruction and demise or increased
susceptibility to pests and disease. Seed germination for temperate seed decreases as temperatures rise
above 85°F and seed may need cold stratification for success (if they germinate at all).
(Example: Asclepias tuberosa, Butterflyweed, Hardiness zones 3a-9b, Heat zones 10-1, cold stratify seed).