San Joaquin UC Master Gardeners

Smart Gardening Conference

September 29, 2012

“A fertilizer is any material containing at

least one of the essential elements for plant

growth that is added to the soil for the

purpose of supplementing the plant nutrient

supply.”

Sixteen elements are required for plant

growth.

Carbon, hydrogen and oxygen

Macronutrients: nitrogen, phosphorus,

potassium, calcium, sulfur, magnesium

Micronutrients: manganese, zinc, boron,

copper, iron, molybdenum, and chlorine

Nitrogen: Encourages healthy vegetative,

green growth

Phosphorous: Phosphorous contributes to

many fundamental plant processes such as

strong roots and setting flower buds

Potassium: Potassium (aka Potash)

contributes to the overall health and vigor of

plants. Helps the plant through stressed

times such as disease/insect damage,

drought and cold temperatures

Numbers represent the percentage of

nutrient compared to filler ingredients. A 10-

10-10 fertilizer contains 10% of each

nutrient.

A 10 pound bag of fertilizer labeled 5-10-5,

would contain 5% nitrogen, 10% phosphorus

and 5% potassium. The remaining 80% could

be comprised of other nutrients and filler.

50-lb bag of 10-10-10 fertilizer

Multiply 50 by 0.10.

Do the same for calculating the amounts of

phosphate and potash.

A 50-lb bag of 10-10-10 contains a total of 15 lbs

of nutrients: 5 lbs nitrogen, 5 lbs phosphate and

5 lbs potash. The remaining weight is filler,

usually sand or granular limestone. Another

example:

Multiply 50 by .08, which equals 4.

To calculate the pounds of phosphate: There

is no phosphate in this bag of fertilizer.

To calculate the pounds of potash: Multiply

50 by .24, which equals 12.

A 50 pound bag of 8-0-24 fertilizer contains a

total of 16 lbs of nutrients: 4 lbs nitrogen, 0

lbs phosphate, and 12 lbs potash. This would

leave us with 34 lbs of filler.

Fertilizer Lingo

Complete Fertilizers: Fertilizers that

contain all three major nutrients are

considered complete fertilizers. (10-10-10)

Incomplete Fertilizer: Lack one or more

major nutrients such as a fertilizer labeled 0-

20-20

Contain either equal amounts of each major

nutrient (N-P-K ratio 12-12-12) or a slightly

higher percentage of nitrogen than of

phosphorus and potassium (such as a 12-8-6

product).

Are intended

to meet most plants' general

requirements throughout

the growing season.

Are formulated for specific needs.

They're aimed at the gardener who wants a

particular combination of nitrogen,

phosphorus, and potassium for certain plants

or garden situations.

These feature the N-P-K ratios determined to elicit the best performance from the particular plant, as well as other elements proven valuable to that plant. Examples would be

citrus trees and acid-loving plants such as camellia and rhododendron.

These products are derived from the chemical sources listed on the product label.

Faster acting than organic kinds and provide nutrients to plants quickly, making them a good choice for aiding plants in severe distress from nutrient deficiencies.

Typically cheaper than organic

Derived from the remains of living organisms; blood meal, bone meal, cottonseed meal, and fish emulsion are just a few of the many available types.

Organic fertilizers release their nutrients slowly: rather than dissolving in water, they're broken down by bacteria in the soil, providing nutrients as they decompose.

Since plants can take up nutrients

continuously, it may be beneficial to provide

them with a somewhat steady supply

throughout their most active periods of

growth.

Slow-release fertilizers contain one or more

essential nutrients.

These elements are released or made

available for plant use over an extended

time period.

Liquid fertilizers are water-soluble powders or liquid concentrates that mix with water to make a fertilizer solution.

The liquid nutrients generally last 1 to 2 weeks, so you need to reapply often.

They are quickly absorbed, so plants get their benefits soon after you apply them.

They are great as a starter solution and for a quick boost during the growing season.

When properly diluted you also negate the chances of fertilizer burn.

Properly diluted liquid fertilizer is ideal for use of soft, sensitive and young plants.

Granular fertilizers are meant to be worked

into the soil or sprinkled around plants.

They last 1 to 9 months, depending on the

type

After application these types

of fertilizer should be watered

in immediately to avoid the

plants burning

Manures can be used to increase soil fertility.

When manure is spread in the spring, even if aged, it is safest to wait for at least one month before planting crops.

When composted manure is spread directly over the soil, it is helpful to add about 40 lbs. per 100 square feet, turned into the top 6 to 9 inches.

“Fresh” manure also can damage plant tissue and kill seedlings. It is too “hot” make sure you use manure that has been processed or composted.

It is not recommended that homeowners use

any manure from dogs, cats, or other meat-

eating animals, since there is risk of

parasites or disease organisms that can be

transmitted to humans.

Compost feeds the soil and fertilizer feeds

the plants.

Compost and organic fertilizers can work

together.

The organic matter in compost sponges up

the fertilizer nutrients until they are needed

by plants.

Compost also provides many nutrients that

plants need in small amounts, such as boron.

Primarily need nitrogen but many crops also benefit from some complete fertilizer (5-10-5, 5-10-10, 8-16-16, and 12-12-12).

Apply these fertilizers at rates of 1 - 2 pounds per 100 feet of row.

Consider light but frequent applications of nitrogen fertilizer every 3 to 4 weeks.

Avoid letting the fertilizer come into contact with the plant stems to avoid burning.

Not using compost or manure? Apply fertilizer that contains both nitrogen and phosphorus before planting.

Young fruit and nut trees in the pre-bearing

years (the first 2 -3 years) can use more nitrogen

per canopy area than mature, fully-bearing trees

Wait until early summer when there is 6 to 8

inches of new growth.

Apply about 2 oz of a nitrogen fertilizer, such as

ammonium sulfate (21-0-0), or 16-16-16 or 1 oz

of urea (46-0-0) or 2 pounds of compost once a

month until leaf fall.

Scatter the fertilizer on the soil under the tree,

keeping it at least one foot from the trunk and

water it in

Different varieties have

different needs

Fully-bearing, average-sized

mature trees in the home

orchard should be fertilized

at the rates stated in

Calendar of Backyard

Gardening Operations for Selected

Temperate Fruit and Nut Trees.

(This handout can be found at the fruit tree display)

Use a fertilizer labeled for citrus

Most mature citrus require

regular fertilization with nitrogen.

Nitrogen should be applied in January or February

just prior to bloom. The second application then

can be applied in May and perhaps a third in June.

Avoid late-season fertilization as it may affect

fruit quality, delay fruit coloring, and make the

rind rough.

Water the tree the day before, broadcast the

fertilizer over the root zone and water in well.

Withhold fertilizer from fall through midwinter.

Acid-loving plants thrive in a pH range of 4.5

to 6.5.

Azaleas, Rhododendrons, Gardenias

A complete fertilizer designed for acid-loving

plants

Fertilize during the growing

season, not the dormant

Add the following to the soil:

For hydrangea blooms to be blue- lower pH

A fertilizer low in phosphorus and high in

potassium is helpful in producing a good blue

color-25/5/30

A solution of 1 Tbsp aluminum sulfate per gallon

of water be applied to plants (which are at least

2-3 years old) throughout the growing season

For hydrangea blooms to be pink – raise pH

Add dolomitic lime several times a year

Use a fertilizer with high levels of phosphorus.

Do not fertilize at planting time.

Four weeks after planting, use a 10-10-10

fertilizer that contains ammonium sulfate or

a potassium sulfate.

Sprinkle 1 ½ tbsp within 12-18 inches of each

plant, but not directly on the crown or stems. Or

use organic-based fertilizers such as blood,

feather, or fish meal at the

rate of 1 pound per plant.

For flowering annuals, use an all-purpose plant food, such as a 5-10-5 or 10-10-10 formula.

Flowering plants have a special need of phosphorous and potassium to reach their blooming potential. Phosphorus will

encourage big healthy blooms

Foliage plants will flourish with a formula higher in nitrogen

Trees, shrubs, & vine apply 0.2 lb N in a 3 ft

x 3 ft area around base of plant immediately

after planting, again 6–8 weeks after

planting, and the following spring

Fertilizer should be applied at the “drip line”

of trees and shrubs and not directly on the

trunk or crowns.

Newly planted groundcover: 1–2 lb N per

1,000 sq ft immediately after planting and

again 6–8 weeks after planting

Usually when fertilizer is needed, only

nitrogen is necessary. Apply fertilizer to the

soil surface for these plants.

Broadcast about 1 to 3 pounds of actual nitrogen

per 1,000 square feet of planted area for shrubs

or per 6 inches of trunk diameter for trees.

With few exceptions, trees do not respond to

supplemental fertilization in California.

In fact, fertilizing healthy woody plants can be

harmful by encouraging excessively vigorous

growth.

Nitrogen and iron are the only nutrients in which woody plants are commonly deficient

Fertilize only as needed and only if other problems have been eliminated as the cause of poor growth.

Avoid overfertilization, especially with high nitrogen fertilizers. Overfertilization promotes excessive foliage that

may increase populations of pests such as mites, aphids, and psyllids. Excessive growth may cause bark to crack, allowing entry of fungi. Excessive fertilizer may also kill roots and burn or kill foliage.

Roses in general are heavy feeders. Roses

love being fed, and will reward you with

more blooms if they are fertilized

Stop fertilizing about

6 weeks before the

first frost date

How often to apply is a subjective decision,

based on the amount of time and devotion

you have.

What type of rose grower are you?

You like to look at roses from your window, but don't know the varietal names and only cut a few for the house.

Use a granular food with of about 10-10-10, applied every four weeks according to directions.

Fish emulsion applied as a liquid fertilizer when buds are about pea-size (about three weeks before each bloom cycle) will enhance bloom color.

Add chelated iron for rich green foliage.

During June, July and August, reduce the amount of fertilizer applied by half during but stay on the same 4-week frequency.

Realizing roses require a steady source of

food, and having the time to supply it, you

are willing to adopt a bi-weekly fertilizer

program for the big blooms.

Start with an application of granular food as

first growth appears in Spring.

Then begin a program of liquid fertilizers

every 2 weeks

Add Epsom Salts at 1/4 C per bush, either

dissolved in the liquid feeding or sprinkled

straight from the package onto the soil

Your "main line" is your hose, and you have

had it surgically attached to your hand, since

you fertilize weekly.

Your main goal is a trophy in a local, district

or national rose show.

Use the previous mentioned rotation of

fertilizers on a weekly basis, but reduce the

concentration to about half of that called for

on the label.

The majority of house plant fertilizers are

about 20-20-20

Frequency of fertilizer application varies

somewhat with the vigor and age of each

plant.

Houseplants should only be

fertilized during periods of active

growth.

Plants in low light will not need

as much fertilizer. Brighter light

will need more

A general guideline to use is to fertilize

monthly in the spring and summer and only

two or three times in the fall and winter.

Never fertilize when the soil is dry.

Pots should be leached every 4 to 6 months.

Leaching is accomplished by pouring an amount

of water equal to twice the volume of the pot on

the soil and letting it drain completely.

This will flush out salts left behind by fertilizers

So many plants to fertilize so little

time to cover them all!

We’re here to teach you where to find the

answers!

Start by clicking

here

You will see the

following list

Click on fruit

trees and you

will get this list

Along with other helpful

information for growing

avocados including planting,

harvesting and pests you

will get specifics on

fertilizing

Why there is no magic number for turf There are so many different

types of turf grown in our county (Cool Season vs. Warm Season grass)

Size of lawn

Temperature

Soil types

Recommend using IPM site Identify turfgrass species if you don’t know what

you have

Will calculate how much to apply by entering species and area of lawn

Map of entire

state

Red Fescue

Don’t Know?? That’s ok! Use the turf key

Nitrogen is the only nutrient that turf grass

needs on a regular basis.

In general, lawns should be fertilized about

4 times a year with 1 lb. of nitrogen at

each application

Both cool-season and warm-season grasses

require 4 - 6 lbs. of actual nitrogen per year.

This amount is usually divided into 4 applications

of 0.5 to 1 lb. of actual nitrogen per 1000 sq. ft.

per application.

Grasscycling supplies about 20% of the

fertilizer requirements of most grasses.

Leaving your clippings on the grass after

mowing is beneficial as it returns nutrients

back to the soil.

It is only beneficial if you follow proper

watering, mowing, and fertilizing guidelines.

Not this

Nitrogen: Older leaves, needles are yellowish; new growth sparse, undersized; plants grow slowly and may drop foliage prematurely.

Iron: New foliage small and yellowish, except green along veins; dead spots may develop between veins; leaves drop and dry prematurely.

Zinc: Leaves yellowish; new growth may be delayed; new leaves may be small, narrow; foliage may be purplish.

Phosphorus: Foliage dark green, bluish, or may develop spots; shoots short and spindly; slow growth.

Potassium: Foliage growth is sparse; older foliage is yellowish and may have brown tips and margins near leaf edge or between veins.

Follow the directions on the package for how

much to use and how often to apply it.

Overfertilizing is worse for plants than

feeding them too little.

Too much fertilizer causes rapid, weak

growth that is susceptible to damage by

pests and diseases, and excess fertilizer runs

off and may find its way into the water

table, causing pollution.

More is not better!

Questions?

Citrus

http://homeorchard.ucdavis.edu/files/140618.pdf

Fruit trees: http://homeorchard.ucdavis.edu/calendar.pdf

http://hoorchard.ucdavis.edu/fertilizing2.pdf

blue berries: http://ucanr.org/sites/gardenweb/Berries/?uid=25&ds=466

landscape trees: http://anrcatalog.ucdavis.edu/pdf/8045.pdf

Lawns

http://www.ipm.ucdavis.edu/TOOLS/TURF/MAINTAIN/fertwhen.html

http://www.ipm.ucdavis.edu/QT/lawnfertilizingcard.html

http://www.ipm.ucdavis.edu/TOOLS/TURF/MAINTAIN/ferthow.html

sunset crash course: http://www.sunset.com/garden/garden-basics/crash-course-fertilizers-

00400000015144/

woody plants" http://www.ipm.ucdavis.edu/PMG/GARDEN/ENVIRON/fertilwood.html

Reading bag: http://www.calfertilizer.org/Fertilizer%20Facts.pdf

woody plants: http://ucanr.org/sites/UrbanHort/files/80113.pdf

types of fertilizer: http://flowers.about.com/od/Flower-Gardening/a/Choose-The-Right-Flower-

Fertilizer-Type.htm

reading bag: http://gardening.about.com/od/gardenprimer/ht/fertilizerlabel.htm

Houseplants: http://www.ces.ncsu.edu/depts/hort/consumer/quickref/houseplants/fertilizing.html

roses: http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7465.html#CULTURAL