Fertilizer Labels and Calculations

We will learn- How to read labels How to calculate amounts of fertilizer

needed for an area

Fertilizer labels Some information is required by law to be

on the fertilizer bags: Net Weight Brand and grade of fertilizer Guaranteed analysis of each nutrient in

fertilizer Name and address of manufacturer

Other valuable information Some manufacturers add the following on

the bag as well: % of water insoluble nitrogen Potential acidity Salt index Source of carrier % of minor elements Calculation rates How to calibrate spreaders

How much fertilizer? We have a grass lawn that needs to be

fertilized and Jake has found a bag of 16-8-8 in our garage. If we need to put 1 pound of nitrogen per 1,000 sq ft of our 16,725 sq ft lawn, how much fertilizer do we need to apply?

How do we figure this problem out? Total Fertilizer Needed =

Recommended N Rate Area of Sq Ft% of N in Fertilizer 1,000X

How much Phosphorus has been applied? Assume we are applying it at the

recommended N amount P= Recommend N rate X % of P in

% of N in fertilizer fertilizer

Can figure K amount the same way!

How much to feed plants Vegetables

For a 60ft row 2 ¾ cups to 4 ½ cups ½ early in season Repeat 4-6wks later

Bulbs Amount per plant

1tbsp – 2 ½ tbsp When leaves emerge

Roses Per plant

4 ½ tbsp – ½ cup 1/3 at new growth After every bloom

Deciduous tree/shrub 100 ft2 under leaf

canopy 4 ½ tbsp – ½ cup 1/3 when new growth Repeat twice at 6-

week intervals

More plants… Lawns

Per 1,000 sq ft 1 pound/ 1,000 sq ft Feed 3 times per year

Evergreen tree/shrub and rhododendrons Per 10 sq ft of

canopy 3 tbsp – 1/3 cup Feed half at bud swell Repeat after

deadheading

Flowering Perennials Per plant

¾ cup – 2 cups Half at new growth,

then in 6 wks

Flowering Annuals Per 100 sq ft

1 ½ cups – 2 2/3 cups At planting, then in 6

wks