Planting plants in pots or containers is convenient, as it allows for easy mobility and control over the quantity, especially in cramped living spaces. However, it’s important to note that if your potted plants are placed outdoors, it’s best not to have them directly on the ground, as experts have pointed out the potential consequences.
According to a report by the UK’s “Daily Express,” Josh Novell, the Deputy Manager and Horticulture Expert of the Polhill Garden Centre, emphasized that placing pots and containers directly on the ground, especially during storms and heavy rains, could lead to destructive outcomes.
Novell explained that while many gardeners believe rainwater is harmless or even beneficial to plants, poor drainage and waterlogging can actually cause severe damage to them.
“If pots are placed on saturated soil, even a brief heavy rain can suffocate the roots. Waterlogged soil in pots can block oxygen and prevent nutrients from reaching the roots, making plants susceptible to diseases like root rot, powdery mildew, and leaf spot,” he said.
He provided a simple solution: elevating the pots by using bricks, pot feet, or gravel to lift them 2 to 3 inches (5.1 to 7.6 centimeters) off the ground allows water to drain freely from the pots, helping to maintain healthy roots.
“Elevation is one of the simplest ways to protect plants, requiring no complicated landscaping. It only takes a few minutes but can be very effective during heavy rains,” he added.
Novell emphasized the importance of ensuring proper drainage holes in pots to prevent waterlogging. Gardeners should also avoid placing pots in low-lying areas where rainwater easily collects, increasing the risk of waterlogging.
However, there are exceptions to this rule. Some plants thrive in moist conditions and do not require elevation to prevent water-related issues.
“Some plants actually thrive in moist environments. Aquatic plants, marsh plants, and certain perennials such as calla lilies or astilbes prefer moist soil, so they do not need elevation or additional aeration,” Novell noted.
He also cautioned against common mistakes people make in rainy or humid conditions, such as covering plants with plastic or impermeable cloth to protect them from rain. While it may seem like a good way to shield plants from rainwater, it often has the opposite effect.
Plastic covers trap moisture, creating favorable conditions for fungal growth that can harm plants. It is recommended to use breathable coverings and avoid covering plants if they are robust enough.
In addition, regular checks on pots to prevent waterlogging and avoiding fertilizing before rainfall – as nutrients may be washed away, causing stress to plants – are important practices. After heavy storms, checking for root damage is crucial. If possible, sensitive potted plants should be moved to a sheltered area to avoid further damage.
Now is also a good time to inspect soil composition, Novell suggests. Soil with high clay content or compaction is challenging for natural drainage. Mixing in coarse sand or organic materials like compost can improve drainage, aiding root systems in accessing essential oxygen. Without these measures, even light rain can cause plants to sit in puddles for days.
The “Gardening Know How” website in the United States notes that in most cases, leaving potted plants out in the rain is not problematic. Natural rainwater itself is not harmful, but excessive water can pose issues. Overwatering can lead to wilting, yellowing leaves, inhibited new growth, mossy soil, and overall poor plant health.
Plants need to breathe, and if they are in a moist and soft environment, the roots cannot absorb oxygen, leading to suffocation, akin to drowning. Therefore, it’s not the type of water but the excess water that causes problems.
In many cases, the simplest way to protect potted plants during rainy days is to move them under an overhang.