Fertilizer: There are so many choices...what one is the best? How do I know what I need to put on my lawn?

Today I thought it might be a good idea to share a little knowledge in the field of fertilizer for everyone to use on their home lawns.  As the weather is starting to break, many people are beginning to think about putting fertilizer down on their home lawns as well trying to control any weeds .  Now comes the hard decision...what one do you buy? How do you know if you're getting the best value for your money?Hopefully I can help you make the best decision for your yard this season.

At the Home Depot, there is a full isle of choices for fertilizers which can be somewhat overwhelming if you don't know exactly what you're looking at.  Some bags are straight fertilizers while other bags contain herbicide to hold off crabgrass germination or control summer annual weeds.  What do you need?  When do you apply it?

WHAT DO THE NUMBERS MEAN ON THE FERTILIZER?

First, take a look at the guaranteed analysis of the actual fertilizer.  This is the three number combination you see on the bag.  For example, 30-0-4.  The first number stands for the amount of Nitrogen it contains, the second is for Phosphorus, and the third is for Potassium.  In general, you don't need a fertilizer with phosphorus unless you are fertilizing an area that is newly seeded.  If you have an established home lawn, chances are you don't need any phosphorus.  The most important thing to look at is the amount of Nitrogen

Scott's brand is $4.07/lb N and Vigoro is $3.33/lb N

you will be getting.  A 30-0-10 granular fertilizer contains 30% nitrogen.  So, if you buy a 50 lb bag of 30-0-4, there is 15 lb's of Nitrogen in the bag.  If you want to apply 3/4 lb of Nitrogen to you lawn in the spring (this is a normal rate), then with one 50 lb bag of 30-0-4 you can treat 20,000 sq. ft by applying 2.5 lb's of fertilizer per 1,000 sq. ft. To find out how big your lawn is, visit http://findlotsize.com/

Long story short, if the are two bags of straight fertilizer or both bags have crabgrass preventing herbicides in them and they have the same analysis but one weighs 14.5 lb's and the other weighs 13.35 lb's, just do the math on the price per pound of N and it will tell you which one is the better value. In the picture above, the Scotts bag is $18.98 and weighs 13.35 lb's and the Vigoro is $21.98 and weighs 14.5 lb's.  If you do the math, it's actually a better deal to go with the Vigoro brand fertilizer here.

WHEN DO I APPLY THE STRAIGHT FERTILIZER OR FERTILIZER WITH HERBICIDES?

Step 1: Their are two things you can do to know when to apply a pre-emergent herbicide/fertilizer combination for good crabgrass control and a nice green lawn in the spring. One rule of thumb is to apply the herbicide when Forsythia bushes are half bloomed.  Forsythia bushes bloom when soil temperatures are about 5 to 10 degrees cooler than that needed for crabgrass germination (top 2 inches of soil being 60-70 degrees).  If you see them blooming, it's a good time to put it down.  If you don't have Forsythia bushes in your area or you want to be precise, you can track GDD days at http://www.gddtracker.net/ and if you put in your email, it will send you an alert for good timing.  As of right now, it's looking like the best time to apply a fertilizer with crabgrass control for our immediate area is within the next 10 to 15 days.

Step 2:  A fertilizer with herbicide in it for weed control should be applied this year around the first or second week of May.

Step 3:  In the beginning of June, an application should be made that is a slow release form of Nitrogen (usually says this on the bag).  It should allow you not to have to fertilize during the summer months and will enable you to wait until the fall when the plant is under less stress.

Step 4: Fall fertilizing in our area should be done in the beginning of September.  Applying Nitrogen too late in the year doesn't help the plant because most of the Nitrogen leaches into groundwater instead of being taken up by the plant that is shutting down for winter.

In my opinion, a fertilizer program like the one that the Scott's company lays out for you for a full year that you can buy at Home Depot or Lowes is expensive but will work well on most home lawns.  If there's a competing companies product with a similar program on the pallet next to the Scott's brand, it's probably worth your time to see what the better value is for your money by comparing the cost per pound of Nitrogen.  If you're comfortable doing the math and understand when and what to treat, commercial grade fertilizers can be purchased at the same stores and could potentially save you even more money.

Best of luck fertilizing this year!