Yes, for a season or two, as long as you control moisture. A container keeps seed dry, dark and out of reach of rodents, which is most of the battle. Temperature is the one thing it will not hold for you, since the box tracks the outside air all year. Viability drops faster in a hot box, so vent it, keep bags off the floor and rotate stock.
Nobody wonders about this idly. It comes up while you are standing in the corner of a barn looking at chewed bags under a roof you have stopped trusting, weighing whether the seed would be better off in a steel box out back. Line the two up against each other and steel takes three of the four counts almost immediately.
It wins on rodents outright. It wins on weather, because there is nothing to leak, rot or blow off. It wins on security, because the doors seal on gaskets and the welded lockbox shields the padlock, and seed is worth real money sitting in an unlocked building.
It loses on one count, and it is the count that decides how long your seed stays good.
Seed is alive. It is respiring slowly the whole time it sits, and heat and humidity are what speed that up. Every degree warmer and every point of humidity higher burns through stored life faster. A rule a lot of growers keep in their head: add the temperature in degrees Fahrenheit to the relative humidity as a percentage, and try to keep the total under 100. Seventy degrees and thirty percent humidity is fine. Ninety and forty is not.
An unshaded steel box in a Virginia July does not sit at seventy degrees. Bare steel takes full sun from mid morning, and the air inside runs hotter than the air outside. That is a fine environment for fencing wire and a poor one for germination percentage a year out.
So be honest about the timeline. Seed going in after harvest and back out at planting, one winter, is a job a container does well, because the cold half of the year is the easy half. Seed you intend to hold two or three summers wants a cooler place than an unconditioned box in an open field, and the way to know for certain is a germination test before you plant, not a guess.
The moisture problem in a sealed steel box is condensation. Warm damp air inside meets cold steel overnight, water forms on the ceiling and the upper walls, and by morning it is dripping. Growers call it container rain. It is not a leak and no amount of checking the roof will find the source, because the source is the air.
Beyond those three, the usual habits still apply. Sealed pails or bins for anything you really care about, a bag of desiccant tucked in with small quantities, and a thermometer with a humidity readout hung inside so you find out what your box actually does rather than assuming.
A mouse gets into a wood seed room because wood gives. It gnaws a corner, follows a gap around a door frame, comes up through a floor board that has softened at the edge. Every one of those routes needs something a container does not have.
The walls are 14-gauge weathering steel. The floor sits in a welded steel frame. The cargo doors close on rubber gaskets built to keep an ocean out of a cargo hold, which is a considerably higher standard than keeping a mouse out of a bag of clover seed. There is no soft edge to start on.
Two honest cautions. First, whatever walks in with you can stay: sweep the box out before it is loaded and do not stack seed against feed that is already infested. Second, if you add vents, use vents with screens. An open hole in the wall is a doorway, and the point of the vent is airflow, not access.
A seed container that works is a seed container you actually walk into. Shelving down one side at working height, pallets on the floor for the bulk bags, older lots in front where you will grab them first, a light so you are not doing this by phone flashlight in February.
Most of that is easier to add before the box leaves the yard than after it lands in your field. That work happens in our own shop instead of getting subcontracted, so screened vents and heavy shelving can be in place the day the box arrives. Say what the box is for when you ask for a quote and we will size the venting to the load.
Delivery and leveling are free inside 75 road miles of Woodlawn, so the whole thing arrives set on blocks and sitting level, which is what keeps the doors sealing for the next few decades. Call (276) 237-6144 and tell us what you are holding and how long, and you will get a straight answer, including if the answer is that your seed wants somewhere cooler than steel.
We will size the venting to the load and set the box level on blocks, or tell you plainly if your seed wants somewhere cooler than steel.
Same-day reply. We'll send a real number, a real delivery window, and any photos we need to confirm fit.
You'll hear back from us today (or first thing tomorrow if it's late). For anything urgent, call (276) 237-6144.