How to Properly Store Your Garden Sprays, Potions, and Powders

As any gardener will tell you, trying to keep track of your amendments and sprays is a bit of a guessing game and can be really confusing. Especially after a few years of accumulating things acquired for one specific purpose. Do you store it outside? In the fridge? In the bathroom cupboard under the sink? Sprays, fertilizers, and all the other things we use to make a garden grow are expensive, they take up space, and they all have their own storage conditions. Having this handy list at the ready will not only help you to keep them in the best condition, you’ll also know where to find them when you need them.

There are basically 3 kinds of storage we’re going to talk about. Dry cool storage (root cellar or fridge), room temperature storage, and non-insulated outside storage – like a garden shed. Now I assume that your outside storage conditions fluctuate a lot in terms of temperature and humidity. Plastic bottles will remain unaffected but metal containers can rust, and cardboard tubes and boxes can get damp and swell and eventually come apart. Where we live it’s dry in the summer and cool and damp in the winter. Paying attention to the condition of your bottles and tools will give you a fairly good idea what’s going on. When deciding the best storage place remember to read labels and no matter what the product is, nothing is hurt by keeping it in the dark and generally most things like to be kept dry. So that narrows things down a bit. Sunlight can affect lots of different products making some of them ineffective, so a dark storage place is a must. If you can’t find a good dark storage space, then a dark colored plastic tote with a tight fitting lid will serve this purpose very well. Your tote is easy to label and carry around, makes it harder for children and animals to get into, and provides a dark space. But be cautious not to leave anything in a closed container that could make gas or fumes that are combustible. If you have things like stored oils and fuel they should be stored in approved containers in a well ventilated space like an outdoor garage.

Choosing an outdoor storage area can be as simple as a shelf in the garage or a garden shed. Be sure to keep things in their original containers and if you feel the need to, you can put these inside a tote or other plastic box for safety. Root cellars or fridges are good for storing products that need to be kept alive and stable to help them remain dormant, this would include certain bacteria, insect larvae, and nematodes. Be sure you know what temperature to store them at and that your fridge is kept at that same temperature. Accidentally freezing some products can render them useless. Room temperature storage is probably the most common and also potentially the most hazardous. Improper storage can lead to leaks, fumes and accidental poisoning. I’m not saying that everyone has to go organic and throw out all the chemicals, what I am saying is that finding a secure storage location is key. A heated garage may be ideal, or a basement workshop. You have to look around your home and decide which space will work the best and be the safest for you.

A note about diluted mixes. Many of the things we buy to use in our gardens are sold as a concentrate and we then dilute them down with water. Spinosad, liquid fish fertilizer, etc. The recommendation from all the manufacturers I read was that it’s best to only mix up the amount you’re immediately going to use. Why? Some products can ferment and produce gas, some breakdown, and some separate into oily substances that will gum up your spraying equipment. It’s best to just mix up what you need for your job and then not have to worry about wasted product or storage. On a personal note, yesterday I discovered a 4 liter bottle of diluted fish fertilizer and it’s ready to burst. The kids obviously premixed it, put on the lid, and made it half way to the garden before getting distracted. This isn’t something you’d want to suddenly pop and gush all over the inside of your house.

Thanks to Montana State University Extension for their help compiling my list. I am including a link below so that you can check out their much more comprehensive lists of product storage. We’re organic at our place, so the list of things we use may be different than what you are using. I’ve tried to cover a wide variety of products, but I’d love to have some additions to the list so please comment below. As with anything, please use common sense, read manufacturers labels, and check for expiration dates.

Recommended Storage for Common Garden Items

Garden Items that Can Be Stored Outdoors

Many common garden items can be safely stored outdoors. The storage space you choose should be dry, protected from children and animals, and out of direct sunlight.

Fertilizer (powder or pelleted) – Store in original bag that’s tightly sealed or place the bag inside a 5 gallon bucket with a lid. You really want to keep your fertilizers dry or they will cake up into a hard block. This storage method applies to anything that should stay dry.

Diatomaceous Earth (DE) – Since it’s just ground diatoms this powder will keep fine indoors, outdoors or wherever you like. Be sure to keep it dry and in a sealed container or bag to stop the dust from getting airborne and flying all over the place. A plastic milk jug with a lid or even a thick zipper style storage bag will work.

Soils and Composts – In their natural forms they’re full of soil organisms and beneficial bacteria and fungi. Freezing is not a problem, it’s a natural process after all so leaving bags outside is fine. For easy lifting in the spring, I’d recommend that the bags be raised off the ground a little on a pallet and the bags be covered with a tarp to prevent excess water from entering them over the winter and making them waterlogged and too heavy to move.

Lime (any form) – Whether you’re storing the round pearls of dolomite lime or powdered hydrated lime, the most important thing is that they must stay dry. Store the bags up off the floor to avoid the rising dampness that’s common in some areas in winter. Or better yet, use the lime as needed on your garden in the fall and give it time to work in over the winter – then no storage is necessary.

I should mention that many of these products are applied with sprayers and other equipment. We use one sprayer for oil based products and one for non-oil based. Some people use a different one for each product, and that’s fine too. My advice would be to make sure that at the end of the season you thoroughly clean your equipment and store it in a dry location. I’ve found that indoor storage works best because it stops any minute traces of oil from becoming gummy over the winter. There’s nothing more frustrating than having a beautiful winter’s day on which to spray dormant oil on your trees and then finding your sprayer is gummed up and useless.

Fall is fast approaching, and now is a good time to look at your tool storage. Most of us store our larger tools like tillers and shovels outside in a tool shed. And that’s perfectly fine. Just make sure it’s a dry location and that there’s some ventilation if you’re storing anything that uses fuel. You do not want a build up of fumes to suddenly spark and cause a fire so be sure that things are properly capped and that there aren’t piles of oily rags on the floor or workbench. Ventilation is important. To help keep your tools in good condition there are lots of things you can do now to make your spring gardening easier. Oiling your metal tools is a good way to help preserve them over the Winter, and it gives you an opportunity to examine the handles and make sure everything is in proper working order, ready for the following year. If you need a new handle or a whole new tool, you’ll have all winter to compare options and shop for one. Wheelbarrows can benefit from a good look at the handles to see if they need oiling or painting and maybe the barrow could use a good coat of rust paint – as could tillers and other heavier equipment. And as any mechanic will tell you, it’s very important to drain the fuel out or add stabilizer in all your tools and equipment that won’t be running over the winter. Again, fuel will separate and cause gumming up of the combustion chambers and all the fiddly little tubes in an engine. It’s worth the small price to pay for buying a bottle of stabilizer and adding it to all the fuel tanks and storage containers you have. Be sure to follow the manufacturer’s recommendations.

Happy gardening! I hope things are coming along well for your harvest and that you’re already thinking ahead to next year’s improvements. If you have some favorite amendments or sprays that aren’t included in the list above – use the comments section below to let us know what they are. We’ll update this list sometime after we get your feedback.

Thanks to the Greg Johnson, Pesticide Education Specialist, and Robert Hendrickson, Program Assistant, from the Montana State University Extension Service for the information they share in the MSU Extension Service publication Montguide MT 8706.

You can read/download the full PDF here: Cold Weather Storage and Handling of Liquid Pesticides