What Are The Numbers On Fertilizer? What Are The Different Types Of Grass?
With so many different fertilizers out there and so many different grasses, its no wonder there is so much confusion. Believe it or not each fertilizer out there as similar as they might be has been designed to serve a particular need. Lets understand what the numbers mean and then lets learn about grasses.
N= Nitrogen Nitrogen is the first number and it is used to green your lawn and plants. Nitrogen is needed in different amounts at different times of the year depending on the grass. It is one of the most essential nutrients of the 12 essential nutrients needed by plants and 1 of the 3 macro nutrients. Warm season grasses need more Nitrogen when it is warm and none when dormant and cool season grasses require more when it it cool. Premium lawn food is high in nitrogen, which is used to feed established lawns in their peak season (28-4-3)
P= Phosphorus Phosphorus is the middle number which is essential for root development and creating blooms. This is a key element in helping with the development of root systems of newly seeded grass and plants. It is number 2 on our macro nutrient list and also essential for plant life. P is the key ingredient in starter fertilizer and root stimulators (18-24-12).
K= Potassium Potassium is the last number and it is used for winter hardiness and it helps a plant survive through the cold season. It helps plants and grass develop a deeper root system, keeping the plant more insulated. You will notice that a winterizer fertilizer will have an elevated amount of K.
Now lets talk about grasses and where N, P, and K fit in their lives.
There are 2 classes of grass. Warm season grass and cool season grass
Fescue is a cool season grass that thrives in the cool or cold weather and struggles in extreme heat. Fescue does not need much N in the the summer because it just wants to survive the heat (90 degrees and above). Too much nitrogen forces Fescue to have to look for nutrients for all the new growth which just stresses it out. When it is hot, what your Fescue needs is a plenty of water. Watering it early in the morning is ideal, as it is with all turf grasses, for this will help reduce risk of disease. When starting your seed, it is recommended that you put down a starter fertilizer or some 10-10-10. This fertilizer balances N with P to help the roots work with the shoots. The best time to throw down Fescue seed is in the fall, therefore it has time to get established before the heat arrives. Spring is also a good time but fall is ideal. Fescue grass seed may say "drought tolerant" that is a lie. There is no such thing as drought tolerant Fescue, only Fescue that is more drought tolerant then others. Fescue does not spread, therefore overseeding is required every few years.
Bermuda Is a warm season grass that turns brown or goes dormant if the fall and winter. Bermuda seed likes starter fertilizer for the same reasons as Fescue but Bermuda seed needs to be put down in the beginning of summer, when it is hot. Bermuda has no trouble with nitrogen in the spring or summer. Bermuda grass has good drought tolerance, but would still prefer to be watered regularly. Bermuda does not need to be fertilized when dormant. Bermuda is an aggressive, spreading grass that is great at repairing itself if needed but can crawl into places you don't want it to if not managed properly.
Zoysia, is just like Bermuda, without the drought tolerance. Many varieties of Hybrid Zoysia has some of the best shade tolerance of most grasses. Zoysia spreads as well and does not require overseeding.
Centipede Grass doesn't need much food and although it prefers sun, it has pretty good shade tolerance. Centipede is different because it does not like Phosphorus, therefore we do not use starter fertilizer when seeding it. Your typical Centipede fertilizer is 15-0-15. It is also a spreading, warm season grass that goes dormant when it gets cold just like Zoysia and Bermuda. It thrives in acidic soil (4.5 to 5.5) and therefore grows well under pine trees which acidify soil. Centipede also does not need to be fertilized when dormant.
I am going to ask my Cali. crew to expound on St. Augustine grass and my Chicago crew to expound on Bahia and Kentucky Blue grass, for they are certainly the pro's with that.
Other related articles:
Hello all. Hortman here in the Chicago area.
Kudos to greengiant for his excellent information on warm season grasses
and the cool season fescue grass. Here in the northern tier of the country we
use three major cool season grasses: Kentucky bluegrass, perennial ryegrass, and fescue.
Kentucky bluegrass is your classic “barefoot” grass. It is slow growing, shallow rooted, and
spreads by underground stems called rhizomes. This makes it very self-repairing and persistent. On the other hand it is a high maintenance grass. It has a low tolerance to heat, is moderately drought tolerant, and doesn’t do well with shade or high traffic. Also it is not very tolerant of insects and disease. You can tell it is Kentucky bluegrass by its boat shaped tip.
Perennial ryegrass is a clump type grass. It doesn’t spread, the clumps just get bigger.
It is fast growing and deep rooted. These features make it excellent for erosion control
on steep slopes. As a turfgrass it has a higher tolerance to heat than bluegrass, is moderately
drought tolerant, and has a high tolerance of insects, disease, and high traffic.
Creeping red fescue is the third of the trio of cool season grasses. It has a higher drought
tolerance than either bluegrass or ryegrass. But where it shines is in heavy shade. It can
handle only 2-4 hours of sun a day.
All three of these grasses can stand alone, but work best as a blend of all three. Their strengths overcome the weaknesses of each other. In establishment, the ryegrass and fescue will germinate and grow quickly to set things up for the bluegrass to come in later. In the heat of the summer the bluegrass can almost go dormant and have disease and insect problems. This is where the ryegrass shines with its resistance to insects, disease, and traffic. Meanwhile, the fescue quietly keeps looking good in the shade. All three use the same starter fertilizer (18-24-12) and peak season (28-4-3) as the warm season grasses.
While greengiant talked about what the numbers meant nutrient-wise, I’m going to talk
about what they mean mathematically. Each of the numbers on that fertilizer bag is the
percentage-by-weight of that nutrient in the bag. To make the math simple I’ll use
a bag of (10-10-10) all purpose. In a 10lb bag, each nutrient has 10% by weight or
one pound in the bag (10% of 10=1). Each of the grasses I talked about has a different
nitrogen requirement per year/1000 square feet. Bluegrass wants 4-6lbs per year, ryegrass 4lbs per year,
and creeping red fescue 1-2lbs per year. You never want to apply more than
one pound per application. Using our bag of 10-10-10, we get 10% of 10lbs = 1lb of
nitrogen. So we would use one full bag of 10-10-10 every application. With the proper
amount your lawn will look great all season. Take care.
Howdy, Hello, and Hi,
Coach Dave here and since I'm on the West Coast the other garden experts thought it a good idea to reply to the "What are the numbers on fertilizer" question, but also what types of grass we use here in California.
(nitrogen) (phosphorus) (potassium)
The easiest way to remember is : UP, DOWN, and ALL AROUND.
15 - 15 - 15
Up: Nitrogen promotes top growth.
Down: Phosphorus promotes good roots.
All Around: Potassium benefits the whole plants health and pest resistance.
When looking at types of grass the drought tolerance, disease tolerance, wear resistance, shade tolerance, recovery from moderate wear, winter color, and heat tolerance are taken into consideration.
Tall Fescue: This is the most popular and is usually found in a seed blend form. This grass is famous for being able to adapt to most types of soils, drought tolerance, disease resistance, and self re-seeding.
Bermuda: Very popular on golf courses, sports fields, and parks. This grass is very resiliant to wear, however the hybrid versions do not produce seed, so yearly re-seeding is needed.
Annual Ryegrass: Many people use this for their lawns during the winter months. When the spring/summer starts it dies off allowing the dormant grass you might have to come back to life.
St. Augustine: This grass is very hardy and recommended for people with dogs because of it's dense growing pattern. It is often associated as being a type of crabgrass because of it's sideways growing root system. St Augustine can withstand salt laden soil such as beach communities. Cold climates and shade make for poor growing conditions of this hardy grass.
If you take a moment to read the fertilizer guide printed on the back of the bag, this will help you with your fertilizing decisions.
Here is lawn expert Dave Kruckenberg in a quick video giving us some great information on fertilizing.
So with N, P, K, which would be the best to use when there is no old grass, and you are starting from the begining
In Valdost G.A.. Sorry I didn't post where I am talking about
Howdy,Hello, and Hi Elaine1,
It's "Coach Dave" at your service. It's warming up and I'm sure your ready to get your lawn in to shape so let's discuss what your options are.
Centipede and St. Augustine grass are the two most common types of grass in your area.
Centipede grass spreads by production of above ground horizontal stems called stolons.
or if you have St. Augustine which produces rhizomes.(underground stems)
Here is what you can use for your established lawn.
Bonus S has 29-1-10 has weed killer added with the fertilizer.
Vigoro Ultra Turf has 28-3-3 is mainly for St. Augustine, but will be fine for Centipede grass.
Hyponex has 15-15-15 and is a general purpose fertilizer, and a great choice as well.
These have different NPK ratings, but they are all formulated for your area.