Fertilizing your plants is one of the critical components to sustain a healthy yard or garden.
But before running out to buy the biggest bag of granular fertilizer you can find, it is important to first ask, how long does granular fertilizer lasts?
This is a loaded question and it can be asking possibly three different questions. Since granular fertilizer does not decompose, it has no expiry date, it can be stored forever as long as it is stored properly. Therefore, if you buy in bulk, you can use it whenever you want, every 2-6 weeks.
How Long Can You Store Granular Fertilizer?
Fertilizer can be saved or stored until you finish the bag of fertilizer.
Granular fertilizer is made up of elements that do not break down, so it does not expire.
Assuming you store it properly. If you leave a bag of granular fertilizer sitting outside or have it left open, the ready-to-use fertilizer will go to waste.
Ammonium nitrate is an inexpensive way to add Nitrogen to fertilizers, however it is highly reactive if ignited.
It could be something as simple as a wayward ember from a bonfire leading to the loss of the bag of fertilizer.
Granular fertilizer is also subject to clumping if moisture is present in the air. Should your fertilizer clump, it will not render it ineffective but you might find it troublesome to use.
When using the fertilizer it will be necessary to break the granules apart again.
A hammer seems to be the best solution to separate the clumps should the fertilizer have clumped.
Following are some tips to assist with keeping your fertilizer is good shape:
- Keep the product in the original bag and place the bag in a plastic or metal sealed container.
- Store in a cool and dry place (garage/shed)
- Avoid sun exposure.
How Long Will Granular Fertilizer Feed Plants?
This depends on if you are using synthetic fertilizer or organic fertilizer.
Synthetic fertilizers are created and manufactured to break down quickly to have an immediate impact on your lawn.
Not only do the synthetic granules break down faster, but the plants will also uptake the nutrients faster since they are available.
This type of fertilizer might be available for a few weeks, but it requires reapplication every 2-4 weeks during your plant’s growth period in the spring and summer.
Organic granular fertilizer takes much longer to break-down. Think of organic fertilizer like compost, organic materials take time for the natural processes to occur to break down into a usable form for the plant.
Organic fertilizer usually takes about six weeks to break down in your soil and tends to feed your plants for a few months, or even a few years.
You can fertilize with granular fertilizer every 6-8 weeks, but be careful to not over apply, which can cause root burn!
Wait! Root burn? What is that?
Root burn is one of the side effects of over-fertilizing. It is tempting to keep applying fertilizer as you see your plants thrive and no one is to blame you for fertilizing by accident.
Be careful: If you data about the lower leaves turning yellow or wilting while the leaf tips are turning brown and there has not been much growth at all, then you might be over-fertilizing.
How Many Applications Can You Get From a Bag of Granular Fertilizer?
In short, the packaging will tell you exactly how many times you can fertilize with the product in that bag!
But before making that purchase, it is advisable to calculate the area that needs fertilizing.
If you have a 5,000 square foot lawn, you will certainly require more fertilizer than a 100 square foot garden.
Then there is also the factor of what you are fertilizing.
Lawns, flowers, vegetables, shrubs, and trees all have different amounts of fertilizer needed, and that also may be a different amount of nitrogen, phosphorus, and potassium in those measurements!
If we take a lawn, to use 1lb of nitrogen per 1,000 square feet is best practice.
A typical bag of lawn fertilizer will tell you how many square feet the bag of fertilizer will cover. If you know the area of your lawn, now you can decide how many times per season you can apply the fertilizer from that package.
The average size of a lawn in the U.S. is around 10,000 square feet. A few states will put that average size over 50,000 square feet, and some numbers of the U.S. will have average lawn sizes of 10,000 square feet or less.
What you generally have to keep in mind is that most bags of fertilizer you would buy will generally treat about 15,000 square feet, so you are likely to go through about 2 bags every couple of months.
Final Thoughts
There is no reason to sweat about buying excessive fertilizer.
As long as you keep the fertilizer sealed in an indoor container and away from sunlight, you can keep using it until you run out.
That is great for a small garden or specialty plant fertilizers, if you don’t need to apply many.
However you will likely come to find out that you will not need to keep lawn fertilizer too long before you need to apply another application again.