Fertilizing Roses!
Potassium (K) Promotes root growth, vigor, and bloom color.
Calcium (Ca) Holds cell walls together and promotes stability and early growth.
Magnesium (Mg) Provides chlorophyll, the green in all plants.
Phosphorus (P) Stimulates root growth, big blooms, winter hardiness.
Sulfur (S) Essential organic compounds of proteins and vitamins.
Iron: (Fe) Promotes dark green leaves and protects from heat damage.

Chemical Fertilizers
Commercial fertilizers are listed by their percentage of nitrogen, phosphorus, and potassium.  Most commercial fertilizers
contain the three main nutrient N:P:K on the label, such as 10-20-10.  Nitrogen is 10 percent, phosphorus is 20 percent and
potassium is 10 percent.  Roses should always be heavily watered before and after an application of chemical fertilizers.  
Never apply fertilizer to dry soil.

Slow Release Fertilizers
There are three types of slow release fertilizers.  The first are materials that dissolve very slowly, such as sulfur.  The
second type of slow release fertilizer is one that requires action by soil microorganisms to release the fertilizer in usable
form.  The third type is once or twice a year fertilizers.  Slow release fertilizers have fertilizer pellets coated with varying
thicknesses of sulfur or resins. Slow release fertilizers time to release can range from immediate to 9 months depending on
the coating.  They also reduce the chances of fertilizer burn.

Water Soluble Fertilizers
As indicated by the name, these are fertilizers in a form that will dissolve in solution.  Mixed with water, the solution can
be sprayed on the foliage (foliar feeding) or used as a soil drench.  The usual recommendation for roses is 20-20-20.  A
water soluble fertilizer can be used as an addition to a complete fertilizing program.  It makes a good quick tonic for a
quick pick-me-up for the plants and as a supplemental feeding during a rainy spell.  Water-soluble fertilizers may be more
suitable for conatiner grown plants than a granular fertilizer.  As always, do not over fertilize - follow the directions on the

Organic Fertilizers
Organic fertilizers are those which come from once-living organisms.  They can range from animal waste (manure) to
ground up organisms (fish emulsion) to former plant materials (compost).  
All organic fertilizers have several characteristics in common:
1.  They tend to be very low in nutrient content.  The nutrients tend to be in slow release form, requiring biological action
from the soil to release the nutrients.  
2.  They tend not to release nutrients unless the soil is warm because the required biological action requires the warmth.  
All organic fertilizers tend to have high levels of carbon to nitrogen, which leads to more break down time needed.
3.  Organic fertilizers (or Mulches) slowly add to the level of humus in the soil.

Commonly used Organic Materials:
Cottonseed Meal
- used to lower pH acidic soil.
Blood Meal - dried, powdered blood, supplies nitrogen and iron.
Alfalfa Meal - best organic soil additive, contains hormones that stimulate growth.
Fish Emulsion - well rounded fertilizer, good source of nitrogen.
Manure - best used as soil conditioners.
Sewer Sludge - granular from, long lasting and non-burning fertilzer.

A major difference between chemical fertilizers and organic fertilizers is the long-term effect on the condition of the soil.  
Constant use of chemical fertilizers without adding organic material to the soil either as fertilizer or as mulch will
deteriorate the soil structure and overall health of the soil.  Add top mulch to avoid over using the chemical fertilizers.

This may help you decide what your roses need:
Low in:  Older leaves turn chlorotic, pale light green to    
completely yellow on the entire leaf but remains on the plant.
Low in:  Reduced growth with reduced leaf size
Low in:  Stems weak and spindly.
Low in:  Small flowers.
Low in:  Flowers lighter in color.
To much:  Younger plant parts are light in color.
To much:  Buds fail to develop after cutting.
To much:  Plant hardening.
To much:  Foliage is increased in size and blooms smaller than normal.
Low in:  Young shoots become hardened and stunted.
sometime become purple.
Low in:  Flower buds may be distorted.
To much:  Plant turns light green to yellow.
To much:  Root loss.
To much:  Wilting of young shoots.
Low in:  Reduction in leaf size.
Low in:  Yellow between veins on leaves.
Low in:  Plants are stunted with large, necrotic white areas on both sides of
Low in:  Large leaves edges may cup down.
To much:  Small black spots on older leaves.
To much:  May also cause iron deficiency symptoms.
Low in:  Pale light green young leaves.
Low in:  Interveinal areas yellow.
Oklahoma Rose Society