HOW TO READ THE LABEL:

To purchase and apply turfgrass fertilizers intelligently, one must be able to read and understand a fertilizer label. Every fertilizer must be labeled stating guaranteed chemical analysis of the material and, in almost all cases, the following label information:

• the name or brand;
• potential acidity
• manufacturer's name and address;and
• net weight of the fertilizer in the bag

The guaranteed analysis is sometimes called the fertilizer grade, which is a listing of nutrients contained in the bag by weight. A complete fertilizer contains nitrogen (N), phosphate (P2O5) and potash (K2O), in contrast to an incomplete fertilizer that's missing one of these elements.

The ratio of fertilizer is the relationship between N, P2O5 and K2O. A fertilizer with a 20-5-15 ratio contains 20% N. 55 P2O5 and 15% K2O by weight. A 50-lb bag of 20-5-15 contains:

• 0.5 x 20 = 10 lbs N
• 0.5 x 2.5 = 2.5 lbs P2O5
• 0.5 x 15 = 75 lbs K2O

Only the nitrogen is expressed as an element, while phosphorus and potassium are present as oxides, meaning the elements are contained in the phosphate and potash compounds, respectively. Phosphate contains 44% phosphorus, and potash contains 83% potassium and expressed in the formulas of their oxide forms, or P2O5 x 0.44 = P and K2O x 0.83 = K.

So, a 50 lb bag of 20-5-15 would have 10 lbs. of nitrogen but only 1.1 lbs. of phosphorus (0.5 x 5 x 0.44 = 1.1 lbs. P) and 6.2 lbs. of potassium (0.5 x 15 x 0.83 = 6.2 lbs. of K).

WIN and WSN, two other terms on a bag of fertilizer, stand for water insoluble nitrogen and water-soluble nitrogen. WSN is quickly available to the turf and provides fast green-up and growth. WIN is slow released by one of several mechanisms, less likely to burn the turf and provides a longer-lastin response than WSN.

Other secondary elements-such as calcium, magnesium and sulfur, and with minute amounts of boron, chlorine, copper, iron an manganese, molybdenum and zinc-are often found in fertilizers and are among the 17 essential nutrients for turfgrass.

 

 

 

Kentucky Bluegrass	Perennial Ryegrass	Fine Fescue
High quality color	Good color and density	Fine leaf texture and dark green
Forms dense sod	Early spring green-up	Early spring green-up & good fall color
Thatch former	Does not form thatch	Can become thatchy
Poor to fair shade tolerance	Fair shade tolerance	Very good shade tolerance
Excellent heat and cold tolerance	Good heat tolerance	Good heat tolerance
Not as durable as perennial rye, but will fill in after injury faster than rye	Will not fill into bare spots because of it’s growth habits	Slow to heal itself in from injury, but will fill in given the time
Medium-good wear tolerance	Very wear tolerant	Medium wear tolerance
Does well in drought but will go dormant with out watering	Quick establishment

Bold items are the real positive qualities for each grass

Green colored item are positive and red items are negative aspects of each grass

 

Fescues have the unusual talent of being able to grow in dry shade.(American-lawns) The fine leaf fescues are the most shade tolerant of all the lawn grasses. Traditionally, fescues are used in mixes with Kentucky bluegrass and/or perennial ryegrass. (Cornell University)

 

Perennial ryegrass will not fill into bare spots or damaged areas because of its bunch type growth habit. It does not form thatch due to its lack of rhizomes. Perennial ryegrass is slightly more shade tolerant than Kentucky bluegrass, but may thin out in shaded areas overtime due to its lack of storage organs. Perennial ryegrass is very wear tolerant. (University of Idaho Extension)

 

Kentucky bluegrass does very well in sunny areas, it is very cold tolerant and will form a dense high quality turf when grown in full sunlight. A limiting factor to bluegrass is its lack of shade tolerance. Under heavy tree shade or on the north side of houses, it will thin and develop a powdery mildew. (University of Idaho Extension) Bluegrass is only a medium-good on wear tolerance, but not as durable as ryegrass.

 

Bluegrass is often incorporated with other grass species to produce a better multi-purpose lawn. A mixed blend can result in improved lawn appearance, earlier green-up, better fall color with better disease and insect resistance. Additions of fescue and perennial ryegrass are included in bluegrass for several reasons. Fescue tolerates shady areas where bluegrass may not get enough sunshine. Ryegrass is often mixed with bluegrass to achieve green-up earlier and its durability. Ryegrass is added to develop a tougher sod that stands up to tougher wear and tear. (Seed land)

 

 

 SEED LABELS

 

 

By, law seed labels list the % of grass type by weight. This, of course, is very confusing because not all seeds are the same size. For instance, bluegrass has 1,500,000 seed per pound while perennial rye has only 250,000 per pound. Even different bluegrasses have different seed counts per pound. So, it takes some figuring (example below), to figure out what % of each grass is actually there. This is called % of grass by seed count and is what really grows.

 

Example: Seed for Ideal Sod

  

 

 

 

By seed count:

Blue =60.88% of 50# = 30.04# x 1,500,000 seed/lb= 45,660,000

PRye =31.18% of 50# = 15.59# x 250,000 seed/lb= 3,897,500

Fescue= 6.63% of 50# = 3.32# x 382,000 seed/lb= 1,266,330

Total Seed= 50,823,830

 

Blue 45,660,000÷50,823,830=90.0%

PRye 3,897,500÷50,823,830= 7.5%

Fescue 1,266,330÷50,823,830= 2.5%

 

Now that’s said, there is one basic fact. Because money is involved, seed labels are forged and just because someone is waving a seed label around does not necessarily mean that is what got planted. So, you still have to do your homework on the performance and reputation of your supplier.