Salts/solids can separate from liquids at below freezing.

I don't know about this one, but a lot of liquid fertilizers freeze between 0C and -5C.

That said, a lot can survive this separation as long as the container doesn't expand so much it breaks or gasses out beyond the seal.

If you do leave it to get below freezing, warm well and shake very well before using it again.

I store urine outside in plastic bottles and the solids separate as NC says.

If it's concentrated it will take colder temps to freeze, but it may well freeze up. Whether it's concentrated in its original packaging or diluted in gallon jugs or whatever, you'll need to leave at least 10% empty space at the top of the container for expansion.

Liquid fert. should be very soluble salts and even if it does precipitate out, it should redissolve with a good shake in the spring. Watch for sediment as some of the ingredients may be less soluble than others. Shake well before using so you don't end up with less P in the top and more in the bottom (for example).

Your plastic containers will most likely crack during winter. It happened to me. In the end, I had nothing left (neither liquid nor container).

What does it say on the container? Most everything I have in liquid (pesticides etc.) have storage requirements right on the label.

Lloyd

The 2-liter soda bottles have not cracked on me yet. If the bottle is too full the cap pops off, sometimes. After using bottles many times over, if the label is still intact I can still run them through the recycling machine and get my money back for the ultimate in use and re-use.

It will probably freeze solid at those low temps. As nc-crn noted, that may lead to some crystallization and precipitation of what's now in solution. If it all goes back into solution when thawed, it should be about the same as when you stored it. Because the container, probably PVC, may become brittle and fracture, it should be kept in a secondary container (e.g. suitable bucket) so that if freezes and breaks the container when it thaws you won't have a loss of the contents.

Wonderful. Thanks everyone for your response.
The city here had issued (at cost) green containers on wheel for kitchen waste collection that I never us (I compost it). I will store the fertiiizer containers in that container which can accommodate.
Now I will tell you how I got these fertlizer containers. Not a happy story. A friend had rented his house to someone and was so much happy with the clients. He once told me that the people were so regular in rental payment and they always bring the cheque to his house. Then two years later he received a call telling him in a hurry that the house keys are in the mail box and to take care of the house & they were gone in a rush. He got fits when he saw indoor gardening in the house, mold and damage etc.
He had to tear apart the house and rebuilt over the foundations. It is good to learn from others experience (client bringing cheques to your house !).

My guess is they weren't growing tomatoes.

What does the label say about storing this product. Three different Grotek products I looked at do not say to not keep from freezing, just "Do not store with incompatible products".
Perhaps a query to the manufacturer would be best.

I'd bury it. But, then, I'm a redneck.

Well, at least they weren't cooking meth with babies in the house...

Methinks their product was a leafy one, not meth...Geez what a mess though! What is wrong with some people?!

Call the company and ask. If their number isn't on the label then google it.

Storing liquid fertilizer for whole winter is a task which needs effort. They need to be properly isolated and stored in a climate controlled atmosphere free from dust. Packing needs to be perfect so as to avoid any spillage. If you can arrange some kind of storage units which includes all the safe storage features apart from just casual storage it is well and good. We stored some useful stuff in a nearby storage unit in Toronto as we moved on from our house for a while.