Why You Shouldn’t Sow Vegetables in Wet Weather (and What to Do Instead)

4th Sep 2025

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It’s September & Autumn has officially arrived and brought a deluge of rain with it! You’ll probably want to be sowing your Winter Vegetables for Spring harvesting, so take note of the tips below to make sure your seeds and/or bulbs get the best start they deserve.

Growing when it’s Wet

There’s a few things to consider before putting seeds or bulbs in the ground when it’s wet.

1.Delay Planting Bulbs

Delay planting your Onion Sets outside when it’s wet due to bulbs rotting in the ground.

Autumn Onion sets / baby bulbs can be planted outside from September to November. However an Onion does not like too much water, it causes rotting to the shallow roots and the rotting spreads to the bottom of the bulb where it sits in the soil.

Alternatives to Planting Onions outside in the rain

It’s always too wet in Autumn & Winter where I live. In Raised Beds, I’ve tried to add drainage to the soil, but it makes no difference. The soil is still waterlogged.

Year 1 – The first year I grew Onions, they rotted in the ground because it rained too much in Autumn & Winter.

Year 2 – I’d read about a method of planting Onion Sets in cell trays first and then planting them outside a month or two later, once they had grown stronger roots.

I tried this method –

Planting sets (onion or shallots) in cell trays first and plant outside

And it worked!

By making the bulb grow roots, the onion bulb is stronger and can survive more stresses that the weather can throw at it. Just take note, if the ground is still waterlogged, delay planting outside until it is dryer.

2. Poor Germination Rates

Sowing seeds in the wet, outside in the soil, could mean no germination.

Seeds need water to activate their seed coat, for the seed to burst out, but not too much water! Seeds can be moved out of the soil, soaked, and could even rot, if they have too much water.

It’s best to wait until it’s dry before sowing seeds outside.

Alternatives to Sowing Seeds Outside in the rain

Sow Winter Veg seeds for spring like Kale, Spring Cabbage, Pak Choi, Chard, Spinach and Winter Lettuce in 9cm diameter pots in a greenhouse or mini greenhouse and plant out in a month or two’s time,
Sow Herbs like coriander, chervil and chives on the windowsill whilst you wait for dryer weather outside.

3. Compacted Soil

Soil is the foundation ration of all growing but when it has consistent rain for a few days, the soil structure is affected.

The soil structure has normal soil particles like sand, clay, chalk, compost, nutrients, air pockets, old roots, stones, bark, coir and an abundance of micro-organisms to move around in the soil and mix it all up ready for plants to grow.

The problem with lots of water is that is compacts the soil, the soil becomes muddy, which falls on the layers below one another and the air pockets are squashed to nothing causing compaction.

Air pockets are important for:

1. Micro-organisms movement through the soil,

2. Oxygen for plants,

3. Plant roots to be able to work their way through the soil.

How to add Air in your soil

Wait for the soil to dry out and add compost,
Add leaf mold, perlite or vermiculite for drainage & air,
Turn the soil with a fork, to add air pockets,
Make sure you have earthworms to turn the soil over.

4. Slugs & Snails Risk

Starting seeds off in the wet also has its pest problems. Slugs and Snails love a rain party!

If your seeds manage to germinate in the wet weather, then you’ve got another problem, hungry slugs. Luckily there are a few things you can do to prevent or divert slugs from your new seedlings.

How to Divert Slugs

Slugs don’t like the smell of = lemon balm, chives, lavender, oregano, rosemary, thyme.
Slugs also don’t like Onions or Garlic including Spring Onions, you could grow these in the same bed,
Slugs tend to avoid = Red Lettuce (but love green), radish, beetroot, celery & tomatoes.
Slugs don’t like: Roses, foxgloves, Holly, conifers.

More Reading – How to Grow Veg & Live with Slugs & Snails