Last Updated on January 29, 2021

How Long Does Liquid Fertilizer Last?

There is no shortage of challenges facing new homeowners. From their first experience with homeowner’s insurance to the question of whether or not to purchase a home warranty (hint: yes, you should) and everything in between, it can feel overwhelming.

It’s always best to turn to professionals for help. As a lawn care expert, it’s no surprise that I receive my fair share of questions about how to grow and maintain a lush, green lawn.

How do I not kill my lawn?

Help! My house is sitting on a dirt lot, and I need grass, STAT.

What on earth are those weird piles of mud dotting my lawn in southern Louisiana? (They’re crawfish mounds, in case you were curious.)

I’ve heard it all.

One scenario has popped up over and over among new homeowners, however.

What do I do with all the old liquid fertilizer I found in my new garden shed? Is it still good? Does liquid fertilizer even go bad? What about organic liquid fertilizer?

Today I’m breaking down everything you need to know about the shelf life of liquid fertilizer and the truth about whether liquid plant food actually does expire.

Granular vs. Liquid Fertilizers – What’s The Difference?

Plant Food

When it comes to keeping your lawn healthy and lush, it needs just three simple things: phosphorus, potassium, and nitrogen. These nutrients help plants develop and strengthen their root systems and enhance that beautiful green look we’re all after.

Of course, they also encourage growth so you can continue to have the pleasure of mowing every two days.

Okay, okay. It’s closer to two weeks depending on where you live. But let’s be real – it can certainly feel like mowing is a never-ending chore, especially when your lawn is adequately fertilized and growing like a weed.

As far as your plants are concerned, there is no real difference between granular fertilizer and liquid fertilizer. As long as they’re getting the nutrients they need to grow healthy, they’re happy.

So what’s the difference between granular and liquid lawn fertilizer? It all comes down to your personal preferences.

Granular Plant Food

As the name suggests, granular plant food comes as dry, solid pellets. These fertilizer pellets are simply scattered onto the surface of your yard.

Some of the benefits of granular plant food include:

  • Granular plant food can be easier to store as it is not as easily impacted by cold weather as liquid plant food.
  • It is more appropriate for heavy applications like a pre-plant application.
  • Granular lawn fertilizer features slow-release options. 

Liquid Plant Food

Liquid plant food is simply a liquid concentrate of the same nutrients found in granular plant food. The concentrated nutrients are added to water, which is then sprayed across the surface area in need of fertilizing, making it an easy, quick way to feed a hungry lawn.

Many homeowners and professionals prefer liquid lawn fertilizer because it is:

  • Easy to apply and handle
  • Fast-absorbing. Liquid particles find their way to the lawn’s root system much quicker than individual granules of fertilizer.
  • Easier to apply uniformly across your lawn.
  • Useful for both in-season use and as a lawn starter.

Does Liquid Fertilizer Go Bad?

Like many who inherited a lush lawn, you may have discovered shelves of old liquid fertilizer gathering dust in your garden shed. What should you do with all of that liquid gold (or green in this case)?

Does weed and feed expire? What about liquid lawn fertilizers?

Good news! Unless it’s been sitting there for more than a decade, it’s likely still perfectly usable.

Liquid plant food has a very long shelf life – around 8-10 years on average, depending on the brand. But there’s a catch.

There’s always a catch.

Liquid fertilizer needs to be stored and handled correctly to ensure long shelf life. Here are some do’s and don’ts for maximizing the shelf life of liquid fertilizer:

To Store Liquid Fertilizer, DO:

  • Store liquid plant food in a cool, dry place.
  • Keep it in its original container to avoid mix-ups
  • Keep liquid fertilizer bottles off the ground and protected from the elements.

When Storing Liquid Fertilizer, DON’T:

  • Let liquid lawn fertilizer freeze.
  • Leave the container open.
  • Mistake sediment for a sign that your liquid weed and feed is expired. Sediment is simply caused by the nutrients settling to the bottom of the container during storage. Just give the bottle a thorough shake, and you’ll be good to go.

As always, be sure to read labels thoroughly to ensure that you’re following the manufacturer’s advice for storage and handling. When stored properly, your liquid fertilizer will be good for years to come.

How to Dispose of Old Liquid Fertilizer

Suppose that liquid fertilizer’s expiration date is just too dubious to trust. In that case, you may decide to simply toss it and start fresh. But before you do that, there are a few things to consider.

The disposal method will depend on whether the product in question is simply a liquid fertilizer or a “weed and feed” product. Weed & Feed products are designed to feed your lawn and control weeds by using a mix of fertilizer, herbicide, pesticides, and insecticides.

If the product you want to get rid of is simply a synthetic or organic liquid fertilizer, it’s safe to pour it down the drain. Just make sure your drain leads to a sewer system and not a septic tank.

If the bottle contains any of the following terms, you likely have a weed and feed product. That means it could contain substances that may be harmful to the local environment.

Look for these red flags:

  • Weed preventer
  • Weed control
  • Insect control
  • Disease control
  • Pre-emergent
  • Plus 2

If you do have a weed and feed product on your hands, or if you’re not sure, your best bet is to take it to your local household hazardous waste collection site for disposal.

If you can’t stand the idea of getting rid of that precious fertilizer, you can always spread the love and give it away to a neighbor or friend. This is an excellent alternative to throwing it out, especially if your fertilizers are synthetic.

It’s also a great way to start out on the right foot with those new neighbors.


Author: Matt Hagens

Matt Hagens

Hi, I’m Matt the owner of Obsessed Lawn. I love to be outside working on my lawn, planning my next project. I created this website to help people like you find the best products for yard care and great advice. Learn more about me and find me on Facebook.