Granular vs liquid

Granular Vs Liquid Fertilizer For The Best Results In The Garden

Liquid vs granular fertilizers

As a soil scientist I enjoy weighing the pros and cons of different types of fertilizers. Comparing granular vs liquid fertilizer forms has surprising results. The answer is hand down liquid fertilizer but why? The two fertilizer forms interact with the soil and plant in entirely different ways. This means yields, blooms and your garden as whole will perform differently depending on the type you choose.

Applying science in the garden making your garden journey a little bit easier by cutting through all the noise. In today’s Gardening in Canada blog post we are going to be talking about granular versus liquid fertilizer. I personally enjoy liquid fertilizer especially in the beginning phases of the plants journey. I also prefer liquid fertilizers if I have a plant in desperate need of immediate nutrient delivery.

Granular vs Liquid Is Apples To Oranges

However, I have used granular forms of fertilizer and enjoyed the result. The convenience factor and the storage ability factor are undeniably beneficial. One thing I want to drive home is that comparing liquid to granular is difficult there two totally different delivery systems of nutrients. however oddly enough granular organic and inorganic act similar in the garden.

When I say similar, I mean the way that it is degraded to be made bioavailable for the plant is a very similar in process. This can be through mechanical weathering such as sun, water, and wind. Or through microbial activity that biodegrades polymer coatings or the organic material containing the nutrients.

Positioning Granular Vs Liquid Fertilizer In The Soil System

When we apply granular fertilizer, it is typically mixed throughout the soil system. This form of application means we have it in situ where it no longer is able to move. This is not a big deal for a majority of nutrients that are water soluble. However, for the nutrients that is not water soluble this can be a problem. With granular fertilizers that contain insoluble nutrients such as phosphorus we have to rely on the roots of the plant getting to that granular position. This must be done in order to uptake the nutrients. Unfortunately, plant roots do not have Spidey sense and are not able to take an education guess as to where the nutrient granule is located. Plants can be lazy, and they will end up releasing something called an exudate which is a fancy word for a sugar.

Exudates & Fertilizers

This sugar is the equivalent of a microbe big gulp and therefore it attracts microbes that then will decompose surrounding organic material. This decomposition process turns the soil carbons-based structures into a format that is usable for the plant. This means the roots no longer have to travel to the area that contains phosphorus they can just produce it within that region.

Liquid Fertilizer Soil Dispersion

Salt build up in soil and how it effects plants

With a liquid fertilizer soil dispersion is a little bit different. This is because it is mixed into the soil water solution. Therefore, we have the benefit of saturating the entire soil system with equal parts of nutrients. Meaning the plants do not have to travel to get those water insoluble nutrients. It has been delivered directly to the root system as a whole. This arguably could be less stressful for the plant especially if it’s going through a rough time.

Best Time To Apply Liquid Fertilizer Over Granular

Liquid fertilizers are far more superior in specific situations. One case where it would be more beneficial for nutrient delivery would be after:

  • Transplanting
  • After a major storm that has caused any sort of stress
  • During a pest invasion whether that be fungal, bacterial or insects

The best way to think of liquid fertilizer is as a protein shake. Granular is the T-bone steak.

Hot Zones In The Soil Is The Granular Fertilizer Issue

Hot zones are common with granular fertilizer. Due to the manufacturing process salts are common in fertilizer both organic and inorganic. However, with a granular system it tends to be a bit more relevant. This is due to the localized area that granular is applied. As water penetrates the system and the granular fertilizer is broken down. Salt will be released into that general area of the grain. If you have a salt sensitive plant ultimately what happens is the roots will avoid that hot zone.

This evasion of the hot zone is a way for the plant to protect itself from salt burn. that means the nutrients that is not mobile is therefore hard for the plant to obtain without the use of exudates. with a liquid formula we are not out of the hot zone necessarily, but it is dispersed without throughout the entire system. what this means is that if we over fertilize, we tend to get signs of fertilizer burn.

How To Recover From Over Fertilizing

How to recover from over fertilizing

Salts are water soluble meaning we can use the laws of physics and simply drown out the system for lack of a better term. This could only happen with an overapplication of liquid fertilizer. With an overapplication of granular fertilizer we would actually have to remove the plant and all the soil that comes with it. This means starting from scratch. Liquid allows us to back out of our mistakes by simply washing out or flooding out the access levels of salt.

Product Consistency

Consistency in the amount of nutrients in each granule is hard to determine. However, with liquid fertilizer it is almost a guarantee that it is equally dispersed throughout the entire product. It is important to remember that we need to shake a liquid fertilizer in order to ensure equal dispersion in the liquid. If we fail to shake the product, we may end up with more of 1 nutrient than the other as things tend to settle out in the package.

This is especially true with organic fertilizers that do not use agents to help with mixing. The other issue with liquid is that it cannot freeze, and storage is important. If we allow a liquid fertilizer to freeze it is more or less garbage. I personally would not use this on my plants mostly because I would be concerned about potential denaturing of the nutrients.

With granular however storage is much easier. As long as you keep a granular fertilizer moisture free you can let it get as hot as you like or allow it to freeze. Granular is not only cheaper to purchase it lasts longer if you do not use it all within one season. With organic granular it is important that you do allow the product to breathe sometimes. Because organic products are a live and do require some microbial activity to stop it from going completely anaerobic. You will know an organic granular product has gone bad if it smells rancid.

The last factor that may go into determining whether or not you want to use granular versus liquid is the convenience factor. How often are you willing to fertilize once a week or once a season? if the answer is once a season then granular is your choice. But if you’re a helicopter plant parent then something like a liquid may be more beneficial.

I hope you guys enjoyed this post if you did let me know in the comments down below and be sure to share. what is your preferred method for fertilizing liquid or granular?

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