Why Are My Plants Struggling After Heavy Rain? (And What To Do About It)

Sarah reached out recently with a question that I reckon a lot of gardeners are asking right now.

"Wondering if I should be using it (soil amendment) in all this rain that we are having. I really want to but the garden beds are so wet I'm not sure if I should?"

It's a great question. And the answer leads into something really important about what heavy rain actually does to your garden that most people never think about.

Why do plants struggle after heavy rain?

You'd think rain would be good for plants. And in the right amounts it is. But when it doesn't stop, something happens underground that starts working against everything growing above it.

When soil becomes waterlogged, the air pockets between soil particles fill with water. Those air pockets are where oxygen lives. And oxygen is what the beneficial bacteria and fungi in your soil need to survive.

When the oxygen disappears, the good biology either goes dormant or dies off. And something else wakes up in its place.

What happens to soil biology when it gets waterlogged?

Healthy soil is full of aerobic organisms. Aerobic just means they need oxygen to live. Beneficial bacteria, mycorrhizal fungi, Trichoderma. These are the organisms that feed your plants, build soil structure, and keep disease under control.

When oxygen is cut off they can't function. Some go dormant. Some die.

And that's when the anaerobic organisms, the ones that don't need oxygen, start taking over. Some of these are harmless. But some of them are pathogens. Disease causing organisms that were sitting dormant in your soil, waiting for exactly these conditions.

Two of the most common are Pythium and Phytophthora. You might have heard of them. They're the fungi responsible for root rot and damping off. They love waterlogged, low oxygen conditions. And without the aerobic biology present to suppress them, they can establish quickly and start attacking plant roots.

This is why plants often look worse after heavy rain, not better. Wilting, yellowing, stunted growth. It looks like a plant problem. But it's actually a soil biology problem happening underground.

Should I use RootWise Balance when my garden beds are waterlogged?

This is exactly what Sarah was asking. And it's the right instinct to question it.

The short answer is: wait until the water drains.

RootWise Balance contains aerobic organisms. Beneficial bacteria, mycorrhizal fungi, Trichoderma. If you apply them into waterlogged, oxygen-depleted soil they're going into the same conditions that are killing your existing biology. They won't establish properly and you'll be wasting a dose.

Wait until your beds are draining again and the soil is moist rather than saturated. Then apply RootWise Balance. That's when those aerobic organisms can actually establish, get to work suppressing the pathogens that thrived during the wet period, and start rebuilding the biology your plants need.

If your beds are draining reasonably well even during heavy rain, it's fine to continue using it. Good soil structure and drainage is the difference.

What can I do right now if my garden beds are waterlogged?

While you're waiting for things to drain there are a few practical things you can do immediately.

Stop watering. This sounds obvious but a lot of people water out of habit. Let the rain do its work and give the soil a chance to drain naturally.

Get a garden fork into the bed. Push it into the soil gently and rock it back and forth without turning the soil over. Do this across the whole bed. You're creating air channels that help oxygen get back in and water drain down. Don't dig. Just open the soil up gently.

Remove mulch temporarily. Mulch holds moisture. Pull it back from the surface so air can reach the soil directly and it can dry out faster.

Don't add fertiliser. Waterlogged roots can't absorb nutrients properly. Fertilising now just adds salt stress to an already struggling system.

Wait three to seven days after the rain stops and drainage improves before applying any biological amendment including RootWise Balance.

How do I stop this happening again?

The best protection against waterlogging damage is healthy soil structure. And healthy soil structure is built by biology.

When aerobic bacteria and fungi are active they produce compounds that bind soil particles together into aggregates. Those aggregates create the pore spaces that hold both water and air. They allow excess water to drain while retaining just enough moisture for plant roots.

Soil that has lost its biology loses its structure too. It compacts. Water sits on the surface or pools in the bed with nowhere to go.

This is why consistently using RootWise Balance through the drier months builds resilience for the wet ones. The biology builds the structure. The structure handles the rain.

What should I plant in winter after heavy rain in Northern Rivers NSW?

Once your beds drain and you've got the biology re-established, winter in the Northern Rivers is actually a brilliant time to grow. The cooler temperatures suit brassicas perfectly.

Broccoli, cauliflower, cabbage, kale, silverbeet, and leafy greens all thrive in these conditions. These are plants that struggle in the heat of a Northern Rivers summer but come into their own right now.

Get your beds sorted after the rain and you've got a great window to get a productive winter crop in.

The short version

Heavy rain doesn't just water your plants. It can water log your soil, cut off oxygen, shut down your beneficial biology, and wake up disease-causing pathogens like Pythium and Phytophthora.

If your beds are saturated, hold off on RootWise Balance until they drain. Fork the soil gently to get oxygen back in. Then apply RootWise to restore the aerobic biology and suppress the pathogens that took hold during the wet period.

The biology protects the plant. Protect the biology first.

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