1. Fertilizer Labels and Calculations

2. We will learn- How to read labels
How to calculate amounts of fertilizer needed for an area

3. 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

4. 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

5. How Much of each Nutrient in bag?
Numbers are percentages.
NPK
Example 50 lb bag
50 x .18 = 9 lbs N
50 x .25 = 12.5 P2O5

6. How much fertilizer?
We have a grass lawn that needs to be fertilized and Jake has found a bag of 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?

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

8. 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!

9. How much to feed plants Vegetables Bulbs Roses Deciduous tree/shrub
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
1/3 when new growth
Repeat twice at 6-week intervals

10. More plants… Lawns Evergreen tree/shrub and rhododendrons
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