For more information on fertilizers see part 1 of this article
(Part one tells about the different numbers on fertilizers and what they mean)
In the last article I was telling you about the numbers on fertilizer and what they mean. Now we'll take a look at liquid vs. granular fertilizer and a few of the differences...
Liquid vs. Granular.
Why are there two kinds and why do you use each?? In the case of granular vs liquid fertilizer one of the most important things to know is the absorption rate (how long it takes to sink into the soil). Almost all granular fertilizer requires 24-72 hours to become fully absorbed into the soil. The time for a liquid fertilizer is faster. It is usually under 24 hours. I do a mix of both depending on what type of grass, the season, etc.
Fertilizer Burn:
You can have too much of a good thing. Having too much fertilizer can burn your lawn. One advantage of liquid fertilizers is that you can control how much is applied much per application and reduce the chances of burning your lawn. Granular fertilizer can be hard to apply evenly and it's almost a guarantee that you will burn your lawn at least once using it. One of the first lawns I did, I didn't have too much luck with. I applied just the perfect blend and amount of fertilizer. So far so good.
The problem came in when it didn't rain for 2+ weeks. Ouch.
This leads me to the next important part... Water lawns generously after you fertilize. This helps your soil take in the nutrients as well as makes burning less likely to occur.
I only apply my granular fertilizer applications when I know it's going to rain or only on customers lawns I know have irrigation systems.
Seasons Matter:
Granular fertilizers are much more effective for pre-winter fertilization when compared to liquid fertilizer. In colder weather the liquid fertilizers have a harder time penetrating the thatch to sink into your soil. (Not to get side tracked but you do know about lawn thatch don't you?) In climates which receive snow a granular fertilization before the first snowfall can be extremely beneficial to an early spring start. This can help your grass be healthier and greener much faster than without a pre-winter fertilization.
Aerating can benefit your fertilization efforts.
Applying liquid fertilizer after aerating can help the fertilizer absorb into the soil much quicker than usual. Granular applications also receive a similar benefit. Even if you've aerated, the same watering rules apply. (see above)
For more on lawn aeration, check this out.
In areas where you get a lot of rain, granular fertilizer will be the better choice simply because it is much less likely to be washed away. The rain will help the fertilizer seep into the soil. This being said, the goof up I had when I first got started applying fertilizers was in an area that normally got several inches of rainfall each month. It just happened I put out the granular fertilizer at a time when it didn't rain for several weeks.