It is best to mulch after rain because the rain will penetrate through to the soil. If you are not expecting rain for days or weeks you can mulch before it rains. Mulch straight after planting fruit trees like lemons, small plants or seedlings to protect your soil, keep moisture in and support the growth of worms.
What happens when you mulch before rain
When you mulch before rain, it will protect the soil and form a barrier between the rain and the ground. When it does rain, the mulch will absorb the water. Once the mulch is full of water it will release it into the soil.
The key mulching before rain is to lay the mulch 2- 3 inches or 5-7cm thick. This will allow rain to go into the soil and reach the plants roots. If you lay mulch too thick, it can absorb the rain water and it will evaporate before reaching the plant.
The best time to mulch
Here is a guide to the best time to mulch each plant type and the best type of mulch to use.
Plant type | Plant Types | Mulch Type | When to Mulch |
Newly Planted Trees | Citrus, palms, camelias, roses, azaleas, tibouchina, | Bark mulch | Straight after planting and top up each year |
Annual Flowers | Petunias, pansy, violas, dianthus, | Bark mulch or sugar cane mulch | Straight after planting |
Flower seeds | Sweet pea, viola | Bark mulch or sugar cane mulch | When seedlings are 1-2 inches |
Vegetable garden | Strawberries, broccoli, peas, beans. | Sugar cane mulch, straw or lucerne mulch | When plants are 1-2 inches |
Vegetable seeds | Bok choy, lettuce mix, chives | sugar cane mulch, straw or lucerne mulch | When 1-2 inches in size, keep mulch away from stems |
Herbs | Rosemary, Thyme, mint, marjoram, oregano, | Sugar cane mulch or lucerne mulch | When plants are at least 3 inches |

How to lay mulch when it is wet from rain
To lay mulch when it is wet from rain follow these easy tips:
- Try not to step inside your garden beds so you don’t compact the soil.
- Wear old clothes – wet mulch will stick to your clothes and can be harder to clean than dry mulch.
- Use a mulch shovel – Mulch shoves are light which will balance out the weight of the mulch.
- Don’t fill your shovel too full and only lift what you feel comfortable with
Mulch gets heavy when it is wet and if the ground is wet then it can become compacted if you step on it to spread the mulch. If you can, let your mulch dry before spreading it. It will make the job easier.

What to put down before mulching
Before mulching your garden beds prepare the soil with organic matter. After you add mulch to the top of your garden beds, it is more difficult to add goodness like compost and fertilizer so it is best to do this first. I always like to think about caring for the soil as much as the plants so doing this before you mulch is easiest.
Mulching a new garden bed
If you are mulching an area to be planted with new plants first dig the soil over, remove weeds and add aged cow manure, compost and sprinkle some pelletized chicken manure. This is great for vegetable gardens, flowers and trees. This will provide long lasting nutrients as it breaks down in the soil.

Mulching under established trees
If you are mulching under established trees, then sprinkle a handful of pelletized chicken manure, particularly for citrus. Then you can lay the mulch over the top. Be careful not to dig or disturb the soil under the citrus trees as they have shallow roots which can be damaged.
Does rain ruin mulch?
Rain does not ruin mulch but will make it wet, heavy and sticky. This can make it more difficult to move by hand and can cover your clothes in mulch. Mulch make from natural materials like sugar cane, bark mulch, tree mulch or hay will naturally dry over time but it is best to cover it with a tarp or keep it under a shelter until you are ready to lay it on the soil.
Rain does not ruin mulch but does make it heavier. One of the benefits of damp mulch is that it won’t be blow around your yard or make any dust as you spread it. All mulch breaks down over time and rain will speed up this process. Any mulch is great, wet or dry.

Should I water mulch after I put down mulch?
You should water mulch after putting it down will help to hold it in place in heavy winds. This will also give you an opportunity to water your plants and make sur that the mulch fully covers the soil. Watering will settle the mulch into place and give you a chance to rake it flat and even it out.
I always water mulch after laying it to make sure that it is weighed down and won’t blow away. This is important if you are using sugar cane mulch or a light bark mulch as there are small pieces which can be caught by the wind. Adding water to your mulch will start the break down process, attract good microbes and support the worm colonies under your soil.
What types of mulch are best for my garden beds?
The best types of mulch for vegetable garden beds are sugar cane mulch, straw or lucerne. Lucerne will have the most nutrients as it holds the most nitrogen. These types of mulch will break down quickly so will need to be replaced every 3 months. They add lots of carbon to your vegetable garden and can be easily dug in when the growing season is over.

Use a mixed bark mulch for flower beds and trees. It contains both larger bark pieces and smaller leaves and stems from mulching whole branches. These are usually made from tree trimmings by local arborists. They make a great mix of green and brown materials and keep the moisture in your soil well. You can also use sugar cane mulch or lucerne however this will break down quickly and need to be replaced every 2-3 months.
Bark mulch is a perfect mulch to use as a path or next to your garden path. It is great to walk on and will help your soil to keep healthy and stay moist. If you choose to move your path, the soil underneath will be better for having the mulch on top.
Should you remove mulch every year?
Don’t remove mulch from your garden beds every year. Mulch will break down slowly over time so you will need to top it up in your garden beds, under trees and around shrubs. In your vegetable garden, when you use sugar cane or straw mulch, this can be dug into the garden bed at the end of the growing season. Replace this with new mulch when you plant out your seedlings in spring or fall.
Should I mulch my vegetable garden?
You should add a light mulch like sugar cane, straw or lucerne mulch around your vegetables. Seedlings like broccoli, cabbage and strawberries will benefit from mulch which will help to keep the weeds down and the water and rain in.
I would not mulch over vegetable seeds like lettuce seeds, bok choy or pak choy. If you cover the seeds with mulch, it will be more difficult for the seed sprout through the mulch. Once the seeds have grown to 2 inches, you can add some mulch around the seedlings.
Should I mulch citrus trees?
You should mulch around your citrus trees. I like to use a bark mulch but you could use straw or lucerne. You will just need add this mulch more often as straw or lucerne will break down quicker.

Adding a bark mulch under your citrus trees will help to keep in moisture, encourage worms to live near your citrus and improve the soil. Just make sure you don’t put the mulch right up against the trunk as this may encourage rot.
The best places to get mulch
The best place to get mulch is from your local municipality. Check on their website as most will be trimming public trees and shrubs and turning it into mulch for public gardens. Many municipalities will sell this to the public for a very good price.
Another great place to get mulch is from a local landscape supplier. You can ring and get them to deliver this to your house or pick it up yourself. Mulch is reasonably priced, and a good tree much will be quite affordable.
The other option is to buy mulch in bags from your local hardware store or garden center. We only have a tiny backyard so I have been buying mulch in bags. I also have to carry everything up a flight of stairs so this makes it easier to bring in mulch to my yard.
Depending on the area you need to mulch, you can decide whether you need a trailer load, a truck load or even just 1 or 2 bags.
Mulch before or after rain – FAQ
Mulch laid before rain as it will help to disperse the water across the soil. Mulching when you have time may be the best thing to do to protect your soil and complete the job. If rain is forecast within the next 24 hours, wait until it has finished and then lay the mulch on top.
The best time to put down mulch is after heavy rain. This will allow the rain to fully penetrate the soil, water your plants and then keep the mulch dry. Wait until after heavy rain to get your mulch delivered as it can get heavy when it absorbs excess rain water. This makes it more difficult to move and it can stick on your clothes and tools.
Mulch will absorb the rain and slowly release it into your soil. This works well to provide an even amount of water to your plants and reduce evaporation from the soil. Mulch will get heavy until it releases the water back into the soil. Keep the mulch 2-3 inches thick to find the perfect balance of reducing evaporation and letting rain water through to the soil.
You can mulch after heavy rain to keep the water in the soil for longer. This will give your plants more time to absorb the water before it evaporates. Mulching before heavy rain can also be a good approach as it can help to reduce soil run off. Try to keep your mulch dry before you lay it otherwise it will be heavy.
Mulch before or after rain – Summary
Mulching after heavy rain will help to allow the rain to fully penetrate through to the soil and provide your plants with a deep water. This will encourage them to grow a deep, healthy root system. After mulch as been applied, it will help to hold water in the soil, reducing evaporation and saving your water in the long run.
Mulching is one of the most important steps you can take to protect and improve your soil. Use a good quality natural mulch and you will have a fantastic garden. Try two of my favorites including mixed tree mulch and sugar cane which both add goodness to your soil and feed worms.
Happy mulching.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.
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