What should you never store in a greenhouse?
A greenhouse quickly turns into a storage room: tools, seeds, old cans of paint, and everything that didn’t fit in the shed end up here. But there’s a downside to this approach: greenhouses are hot, humid, and full of pests, and temperature and humidity are hard to maintain at a consistent level without climate control. Under these conditions, some things don’t just deteriorate — they also create problems for plants and people. Here’s what you should remove from your greenhouse right now.
Why a Greenhouse Is a Poor Place to Store Things
Most home greenhouses are not equipped with climate control. During the day, the air inside heats up significantly; at night, it cools down; and after watering, humidity spikes sharply. Plants are better adapted to these fluctuations than paint, paper, seeds, and metal tools.
The main problem with a greenhouse is unstable conditions. Unlike a dry shed or pantry, items here regularly encounter condensation from temperature swings, heat, and cold.
Damage isn’t always immediately noticeable. A can of paint may look fine until the next renovation, and garden seeds may seem okay until you try to germinate them.
Diseased Plants and Pesticides Are Dangerous for the Entire Greenhouse
It’s tempting to place a sick plant in a warm spot so it recovers faster. But in the warm and humid greenhouse, infection or pests easily spread to neighboring plants. If a contaminated specimen ends up next to healthy ones, diseases and pests can quickly spread throughout the entire greenhouse.
Diseased plants need to be isolated, and outdoor specimens should be inspected and treated for pests before being moved into the greenhouse. Otherwise, insects, mites, or disease pathogens could enter along with a new pot.
Pesticides should also not be left among plants. They are recommended to be stored at temperatures of approximately 4 to 32 degrees Celsius. Some pesticides can catch fire when overheated, so they require a cool, dry, and well-ventilated location.
Seeds, Paper, and Cardboard Deteriorate from Moisture
An airtight container protects seeds from moisture and rodents
A greenhouse is not suitable for long-term storage of seeds and bird feed. Moisture can spoil the contents of packets, especially if the roof leaks or water is accidentally spilled nearby. Additionally, many seeds need to be kept in a cool place to maintain good germination rates.
Another problem is rodents. If seeds are temporarily left in the greenhouse, they should be placed in an airtight container.
Cardboard boxes, paper bags, and plant trays should also be moved elsewhere. In humid air, they begin to soak through, develop mold, and break down. Even neatly stacked cardboard will eventually become damp and unusable.
Paint and Regular Tools Can’t Withstand Temperature Fluctuations
Leftover paint from renovations often gets placed wherever it won’t be in the way. However, in winter, the temperature in a greenhouse can drop below freezing, and in summer, cans heat up significantly. Temperature fluctuations ruin paint — it can thicken, separate, or lose its properties.
You also shouldn’t store good metal tools here, especially older or collectible ones. Humidity accelerates rust formation, and constant shifts between heat and cold can damage wooden handles: they dry out and crack.
You can leave a few hand tools made of stainless steel or plastic in the greenhouse. But don’t store other tools there: humidity will cause metal to rust, and unstable conditions can lead to wood cracking.
It’s acceptable to leave a few tools made of stainless steel or plastic in the greenhouse. Regular metal pruners, trowels, and other valuable accessories are better kept in a dry room.
What You Can Safely Store in a Greenhouse
You can leave items in the greenhouse that are not affected by moisture and temperature fluctuations and that are needed for growing plants indoors.
It’s convenient to keep:
- potting soil;
- empty plastic pots;
- tools made of plastic or stainless steel;
- supplies that are constantly used during transplanting.
The rule is simple: a greenhouse is primarily meant for plants, not for items that need dry and stable temperatures. If an item is sensitive to moisture, frost, heat, or rodents, it’s safer to find another place for it right away.
