Happy New Years to everyone, it’s

going to be good year. Our newest

class of Master Gardener (MG) vol-

unteers have already become highly

active and compliment our veteran

MGs to provide horticultural educa-

tion to the community. So, if you’ve

had struggles with your yard or gar-

den in the past, then be sure to reach

out to the extension service as need-

ed for guidance. Included in each of

our bi-monthly newsletters will be

discussions on important issues you

may need to focus on to get the most

out of your landscape without exces-

sive cost or stress! Follow through,

scout regularly and get the guidance

you need to ensure your yard and

garden performs its best!

We seem to be oscillating between

cold, wet and warm weather which is

fairly common in our region. Watch

out for fungal pathogens and pests,

conditions have been relatively ideal

for infection and population build up.

These warm periods can encourage

plants to come out of dormancy too

early or elicit tender growth, so make

sure to monitor the weather and em-

ploy cold protection tactics as neces-

sary to limit plant injury.

In this Issue

Title Page

Irrigation Calibration ..... 2

Planting Trees Properly . 3

You Say Potato .............. 4

Preparing for Spring ...... 5

Upcoming Classes ......... 6

What to Plant ................. 6

“What’s That” Answer ... 6

For more information contact: UF/IFAS Extension Duval County

Chris Kerr - CKerr@coj.net - (904) 255-7450

Extension Update by Chris Kerr

Volume 2, Issue 1 Jan-Feb 2020

LARVAE

What’s That?

Damage throughout landscape Damage on foliage Damage on fruits

2

Irrigation Calibration

The truth of the matter is, you’re

going to be paying so...you should

really know what you’re spraying.

I’m talking about irrigation water

this time. What better way to avoid

75% of the most common landscape

issues is there than simply follow-

ing proper irrigation? Nothing!

Now, since it’s the law, you proba-

bly know how often you’re irriga-

tion system is applying water. And

hopefully you follow that and make sure the irriga-

tion is applied early in the morning while the dew is

still present to reduce the dreaded leaf wetness peri-

od. But, proper irrigation is so much more than just

how often and when the sprinklers turn on. You also

need to know that the appropriate amount of water is

being supplied and the only way to do that is to cali-

brate the system. Components wear out or get

clogged all of the time, so this should be done at least

once a year. Now is a great time to get it done!

Calibration isn’t overly complicated, and

should be done on each zone individually.

Place straight sided catch pans, coffee

cans, tuna cans, etcetera around the irrigat-

ed zone randomly. Five to ten is usually

sufficient but ultimately the number re-

quired will depend on the size of the lawn

and the number of sprinkler heads. Have a

problem area? Place a few in that area to

make sure you’re getting the information

you need. Turn on the irrigation system

for 15 minutes and then immediately use a

ruler to measure the depth of the water in each con-

tainer. We want to apply 1/2” to 3/4” of water dur-

ing each irrigation even so divide 1/2’ (or 3/4”) by

the measured number and multiply that result by 15

mins to determine how long that zone should be op-

erated to apply the desired quantity of water.

If you notice significant variation between cans ad-

justments, additions, or repairs to individual sprinkler

heads may be required.

What’s the Key?

Accurate irrigation is the key!.

Major Effects of Over-Irrigation:

This often is the major contributing factor we find causing fungal pathogens on lawn and landscaping

plants.

Water soluble nutrients readily leach through our sandy soils, each inch of water applied pushes those nutri-

ents roughly one foot down the soil profile. After just 3” of water those nutrients are lost to our plants; like-

ly your lawns root system isn’t that deep...especially if you’ve been over-irrigating so that loss may occur

even sooner than that!

Your paying for this water and fertilizer that is leached, and we’re all paying for the long term consequenc-

es!

Additional Reading:

Managing Landscape Irrigation to Avoid Soil and Nutrient Losses: (https://edis.ifas.ufl.edu/ss586)

Around the Yard by Chris Kerr

Above: Sprinkler calibration

can be done in just a few

minutes. (Photo M. Gutierrez)

3

Out on a Limb by Larry Figart

Planting Trees Properly Arbor Day in Florida is January 17th. It is one of

the earliest State Arbor Days because it is the perfect

time to plant trees in Florida. If we plant them now,

they have a chance to get established before our dry

season starts in March.

The rule of thumb used to be when planting a

tree was that you should plant it so the tree is

planted level with the natural soil surface. Unfortu-

nately, using this method often plants the tree too

deep. When we plant trees deeper than they need to

be, the root systems lack the oxygen levels that they

need to thrive. Also, with trees planted too deep, the

trunks are covered with soil, promoting decay situa-

tions.

It has been found that even when using the old

rule of thumb, many trees are still planted too deep.

In some cases, the root system in the container or in

the field grown root ball had had additional soil

placed on top of the natural grade during routine

nursery operation. The latest recommendations from

the University of Florida suggest that before planting

the tree the purchaser should remove the soil so that

the point where the top-most root emerges from the

trunk (the root flare) is within the top two inches of

the root ball, It is even preferable that this root flare

be visible. This way circling roots can be corrected

prior to planting.

Speaking of circling roots, the new recommenda-

tion for planting containerized trees is to incorporate

a technique called root shaving. By removing the

outer portion of the root ball the root system quality

is improved by pruning off circling, descending, as-

cending, and kinked roots.

The tree should then be placed so that the root

flare is slightly above the natural soil level. An old

forester friend came up with this saying to help you

remember. It goes like this: ”Plant it HIGH and it

wont DIE”. No soil should be placed on top of the

root ball when backfilling the hole. The soil removed

when digging the hole is the best soil to put back in

the hole when backfilling. No amendments like ferti-

lizer or manure should be added to the hole. The rest

is easy. Water the tree often, apply mulch (not

around the trunk), and stake it if necessary. By plant-

ing the tree at the correct depth in the soil, we are

giving it the best chance for survival.

How Much Water?

Before you select the size tree you are going to purchase, consider how much irrigation you can provide.

Regular irrigation after planting encourages rapid root growth that is essential for tree establishment. Most

trees require their own irrigation source such as a bubbler to get established. Turf irrigation sprinklers are

usually don’t provide enough water for most trees. Each watering should supply 2-3 gallons for every inch

of tree caliper. For a typical tree 2-4” in caliper, watering should take place every day for a month, every

other day for three months, and then weekly until the tree is established. The establishment period is 4

months per inch of tree caliper. Of course, if the soil is wet or saturated, do not water. If the proper irri-

gation cannot be supplied based on the size of the tree, then perhaps a smaller tree should be planted.

Shaving Roots:

Photo Credit: Purdue Extension Fact Sheet

FNR-433-W

4

Growing Potatoes

When to Plant: Jan - Feb

pH: 6.0 - 6.5 Plant Spacing: 7-10 inches

Major Pests: Colorado potato beetle, wireworms

Days to Harvest: 85-110

Additional Reading

Controlled-Release Fertilizers for Commercial Pota-

to Production in Florida.

http://edis.ifas.ufl.edu/hs187

Potato IPM

http://edis.ifas.ufl.edu/topic_potato_ipm

You Say Potato, I Say—Grow Them!

February is the perfect time to plant Irish potatoes in

north Florida. Day length is increasing, and temper-

atures are warming but not yet hot. They are grown

from seed pieces, which are simply tubers whose

eyes (buds) have begun to sprout. You can develop

your own seed pieces, but planting certified seed po-

tatoes will ensure you don’t accidentally introduce a

disease or pest problem.

Potatoes are not hard to grow as long as you know a

few of their specific needs. The tubers, which are

specialized underground

stems, are sensitive to soil

temperature. They need at

least 50° F., form best when

soil temperatures are be-

tween 60-70° F., and fail to

form above 80° F. In addi-

tion to their soil temperature

range, potatoes need well-

drained, slightly acidic (pH 5

-6) nutrient-rich soil, con-

sistent moisture and at least

6-8 hours of full sun. Seed

pieces are planted 3-4 inches

deep with cut side down and

eyes facing up, either in the

ground, or in a deep contain-

er with plenty of room around the seed pota-

to. Roughly 2 weeks after planting the potatoes must

be “hilled.” Rake or pile soil up around the young

plant, burying it up to the crown. Hilling blocks sun-

light from reaching developing potatoes and turning

them green. Sunlight can cause buildup of toxic al-

kaloids and make them unsafe to eat. Continue hill-

ing throughout the growing season as necessary to

cover the tubers. Fertilize every 3-4 weeks after

planting. Hand cultivation will help reduce competi-

tion and keep insects and diseases away from your

crop. Try not to damage shallow tubers!

In about 90 days (more or less, depending on varie-

ty), you can gently dig potatoes for harvest. If you

want to store them after harvest, wait until 2-3 weeks

after the plants die back before digging. Try not to

damage the skins. Place potatoes in a single layer in

a cool, dark well-ventilated area to cure for 10-14

days. This will allow them to

be stored for 3-6 months.

Many varieties can be success-

fully grown here. At the

demonstration garden we are

growing ‘Peter Wilcox,’ a pur-

ple-skinned cultivar with a

golden interior and excellent

taste. It can be roasted, boiled

or fried. In Florida Potato Va-

riety Trials it exhibited high

yields.

Native to the Andes in South

America, potatoes are mem-

bers of the Solanaceae plant

family—along with tomatoes,

peppers and eggplants. Be

sure to plant potatoes in a location that has NOT had

a relatives planted for several seasons. And do not

plant potatoes in the same place they have been

planted within the last 3 years. Crop rotation will

help reduce buildup of insect and disease problems

Growing in the Garden by Beth Marlowe

Plant potatoes in February!

Photo by UF/IFAS Hernando County Ext.

5

Preparing for Spring by Terry DelValle

Maybe it doesn’t seem like spring is just around

the corner but March 20th is the 1st day of spring

and it will be here before you know it. Now’s the

time to catch up on landscape chores and get ready

for the growing season.

Number one on the list should

be to service the lawnmower.

Lawns don’t need mowing during

the dormant season so go ahead

and sharpen the blades, change the

oil and drain the old gasoline. Old gasoline makes

engines work harder and doesn’t ignite easily. Fuel

has about a thirty day shelf life so if it is old, it

should be taken to a hazardous waste center. For

more info on how to handle hazardous wastes: http://

www.coj.net/departments/public-works/solid-waste/

household-hazardous-wastes.aspx. While you are at

it, clean out old pesticides that are collecting dust

because these can be taken to the same place.

Thus far we have had rather mild weather but

chances are good that we will get some cold weather

that will nip back tender perennials (some locations

already have already experienced frost). Once that

occurs, it’s always tempting to cut back plants that

have been damaged by the cold, but it’s better to

wait until new growth emerg-

es around mid-March. Dam-

aged leaves and twigs will

help protect plants from fu-

ture freezes and who knows

what is in store for us over the

next month? A few plants like

gingers or firespike

(Odontonema cuspidate syn.

O. strictum) that faithfully

come back from the root sys-

tem can be cut back to the

ground if they were damaged

by cold.

Rake fallen leaves and place them in the compost

pile or use as a mulch in plant beds or vegetable gar-

dens. Remove old flowers from plants like roses and

camellias. Many diseases and insects winter over on

old fruit, leaves and flowers. A good example is

black spot on roses. The disease can be carried over

into spring if old infected leaves are left on the plant

or allowed to fall underneath. Likewise, old camellia

flowers should be picked up and removed to avoid

camellia petal blight next fall and winter. Old flow-

ers of both camellias and azaleas that have this dis-

ease form a fruiting structure (sclerotia) that will be-

come active when plants bloom next year if weather

conditions are mild with high humidity.

Pick up leaves and or fallen fruit around plants

that experienced disease problems last year. A good

example is citrus; infections for greasy spot come

from the fallen leaves around the base of trees. Mela-

nose is another disease that affects citrus and this one

overwinters in recently killed twigs so to control this

one, prune and get rid of small dead twigs before

new growth emerges. If you use overhead irrigation

to water citrus, change to low volume to keep water

off the leaves and trunk. A soaker hose works great

around citrus and will reduce many of the disease

problems.

In late February, trim back brown

leaves of ornamental grasses before

new growth begins. If ornamental

grasses, like muhly grass, look like

they are dying back from the cen-

ter, use a post hole digger to re-

move the center and replace with a

good garden soil which encourages

the healthy grass to spread. Give

liriope and mondo grass a haircut to remove brown

tips. If coonties or sago palms are heavily infested

with scale insects, prune away all the leaves, discard,

and spray the remaining base with horticultural oil.

Weeds are blooming and setting seeds. Hand-pull

weeds that are flowering or those with seed heads

because herbicides will not work on these. If the

weeds have an underground reproductive structure or

a deep taproot, (oxalis or betony), use a hand tool to

remove the entire plant; otherwise you are wasting

your time. Some annual weeds that come back from

seed every year can be eliminated by adding a fresh

layer of mulch on top of existing mulch. This will

block out the light required for some seeds to germi-

nate, like crabgrass.

March 1st is the target date for applying pre-

emergent herbicides to lawns if warm season weeds

were a problem last summer/fall. However keep an

eye on the weather because the application timing

may be earlier. The time to apply is when day tem-

peratures reach 65 to 70˚F for four to five consecu-

tive days. More info: http://edis.ifas.ufl.edu/ep141.

Look for new growth when deciding where to make pruning cuts

Prune back muhly

grass before spring

growth emerges

6

Upcoming January/February Classes

For all classes call 255-7450 to register and pre-pay

Canning Classes: $20 per person, pre-payment & pre-registration required.

Saturday, January 18, 9 a.m. - 1 p.m. - Vegetable Soup (Cans) & Crackers

Monday, January 27, 9 a.m. - 12 p.m. - Calamondin Preserves

Monday, February 3, 9 a.m. - 12 p.m. - Orange Marmalade

Saturday, February 8, 9 a.m. - 12 p.m. - Cranberry Pepper Jelly

Thursday, January 16, 10 a.m. - 12 p.m., Temperature Fruit Trees for North

Florida. Duval County Extension Office, 1010 N McDuff Ave. Cost is $10.

Tuesday, January 21, 6 p.m. - 7:30 p.m., Plant Propagation: How to Grow More

for Less. West Branch Library, 1425 Chaffee Rd. Free program, but pre-registration

is requested.

Saturday, January 25, 9 a.m. - 12 p.m., Spring Vegetable Seed Starting Work-

shop. Duval County Extension, Superior Street Demonstration Garden. Cost is $15.

Tuesday, February 4, 6 p.m. - 7:30 p.m., Recycle in the Garden. West Branch

Library, 1425 Chaffee Rd. Free program, but pre-registration is requested.

Thursday, February 6, 10 a.m. - 12 p.m., Easy Hydroponics. Duval County Ex-

tension Office, 1010 N McDuff Ave. Cost is $10

Friday, February 7, 9:30 a.m. - 12:00 p.m., Implementing Biological Control.

Duval County Extension Office, 1010 N McDuff Ave. Cost is $10.

Saturday, February 29, 8:30 a.m. - 2:30 p.m., A Day of Gardening. Duval Coun-

ty Extension Office, 1010 N McDuff Ave. Cost is $20

It’s cold damage! If you start noticing damage on a range of different plants at the same time, you should imme-

diately start thinking about environmental, physical or chemical damage. In this case, if you consider the histo-

ry of the site and you realize a frost occurred 3 days prior that will cue you into the cause. Young tender growth

will generally be the first portions of the plant to go, often turning water-soaked within a few hours of the freeze

event. However, you may also notice just the leaf margins, or exterior foliage. When the freeze event isn’t too

extreme the interior foliage is protected through the radiant heat given off by the exterior foliage. Terry dis-

cusses this briefly in her article on page 5 but the short and sweet is for most plants don’t go out and trim off

dead foliage too soon, it will actually serve to continue protecting the foliage below it in the next freeze event.

If you remove it too early you’ve just exposed the next layer to repeat the process. Once the risk of frost is over

and new growth has started get out there and remove those dead portions to open the canopy, improve aesthetics

and limit the chance of disease.

Further Reading:

Cold Protection and Chilling Damage of Landscape Plants (https://edis.ifas.ufl.edu/topic_landscapes_and_cold)

What to Plant in

January & February

Annuals - Dianthus, pansy,

petunia, viola and snapdrag-

on.

Bulbs - Agapanthus, cri-

num, dahlia and gloriosa

lily. These plant produce

foliage in the winter to

flower in late summer.

Vegetables - Beets,

Broccoli, carrot, cabbage,

collards, onions, potatoes,

arugula, lettuce, and spin-

ach.

Herbs - Cilantro, dill, fen-

nel, parsley, sage and

thyme.

Now is a great time to plant

most hardy perennials par-

ticularly trees and shrubs!

What’s That?