The Grass Doctor

What happens to liquid fertilizer if it froze over the winter?

We left the fertilizer out in the back shed over the winter and we didn't notice that it should not freeze. If I put it on my lawn anyways, what will happen? And also what happens to the fertilizer once it has froze?

Public Comments

1. I would use it anyhow. Just shake it up well. It might have lost some potency, but shouldn't hurt a thing.
2. Lok at the label. If it specifically says "do not freeze" then you should consider replacing it because it may have broken down. You state agriculture office can test it but you might be in a TIME important problem and not get your answer in time. If it does not mention it you should be OK with it.
3. I don't think it will do anything. The water is what freezes. The fertilizer contains nitrogen and hydrogen (NH2 i think). If it has not been contaminated and has been kept sealed it should be close to like it was last year, but fertilizer is mostly alkali and it will try to reach pH level of neutrality and this is an indication of the hydrogen content (again I believe). With this in mind you can go to a farm store and ask how they would test left over fertilizer or if freezing has an effect. And like Larry above potency may be down but it would still be better than 0 Id use it an a hart beat knowing what it costs Id sure not dump it. Might cause a lot of weeds to grow than you have to treat the weeds or spend more time mowing them. I know when Ice freezes quickly it traps air and nitrogen in it and this is what causes the white lines and white clouds in ice cubes and in the chunks you might see on ponds and lakes.