What is mulching and mulch mowing?

List of contents

• What is mulching?
• Mulching material
• Mulching in your vegetable garden
• Mulch mowing: natural lawn care

What is mulching?

In ecological horticulture, mulch refers to organic matter – such as leaves or grass cuttings – that is applied to the soil to protect it and supply it with nutrients. Mulching is the process of doing so by adding a loose layer of shredded plant material on top of the soil. Mulching is a valuable method to use in almost every area of your garden, and for home gardeners it’s also a great way to save time, money and effort.

How does mulching work?

Mulching helps soil retain moisture by shading the earth and acting as a blanket. It means water can be stored more effectively in the ground, so the soil remains loose and will not dry out too quickly. Mulching also helps plants to grow by forming a protective layer against heavy rain and cold temperatures. Over time, plant matter used for mulching is broken down by earthworms and soil-dwelling organisms into valuable natural fertilisers and nutrients for plants.

Mulching material

A huge range of natural substances is suitable to use as mulching material, from chipped bark to sawdust – and you might not even need to go to your local garden centre. You may find that your usual garden waste offers everything you need to start mulching yourself. Take a look at our suggested materials and uses.

Shredded wood matter

• Suitable for use under rooted hedges and trees.
• Ideal as a path covering.
• Can accelerate plant growth due to the high nitrogen content released during degradation.

Grass cuttings

• Can be used in all areas.
• Use a layer approximately 2 to 3 cm thick on flowerbeds and plants.
• Don’t apply as a thicker layer because cuttings can clump together and smother the soil.
• Never use diseased grass or grass cuttings that include seeds.

Leaves

• Leaves from birch, maple, beech and all fruit trees can be used freely.
• Leaves from nut, chestnut and oak trees should be used in small quantities and must be mixed with other leaves for mulching.
• This is because they are high in tannic acid, which is very hard to degrade and has a negative impact on the nutritional balance in the soil.

Chipped bark

• Suppresses thistles and other weeds.
• Only suitable for paths and under flowers, fruit trees and bushes, as it can lead to high levels of tannic acid in the soil.
• Not suitable for vegetables and shrubs.
• You should use a layer at least 10 cm thick to benefit from its full effectiveness.

Gravel, chippings and stones

• Inexpensive.
• For use around perennial herbs and shrubs.
• Recommendation: use light-coloured variants in sunny spots as they will not heat up as quickly. Dark variants store heat for longer.
• Water-permeable and breathable.
• Not suitable for dense soil due to its weight.

Mulching your vegetable garden

For your vegetable beds, it’s best to use a mulching mixture that you can apply regularly. Use it sparingly: mulching can attract snails and rodents, so little and often is key. You can mulch with a range of materials and methods that will support the soil and the growth of your plants. Make sure that the grass and plant cuttings have dried out slightly before you sprinkle them over the bed.

Mulching mixture for your vegetable beds

• A “green mulch” uses living plants to cover the soil and bring benefits to your vegetable bed. Look up catch crops and companion plants that suit what you are growing.
• Leaves
• Straw
• Compost
• Grass clippings
• Ideal for: radishes, herbs, cress

Mulching for your lawn – achieve a lush green lawn, naturally

Your lawn can also benefit from an organic mulching technique. In fact, not only does mulch mowing return natural nutrients to the grass, it also saves you time and effort. That’s because you no longer have to collect cuttings in the grass collection basket, as a mulching mower finely chops these clippings and scatters them over the grass. In doing so it combines the three key steps of any lawn care regime – mowing, disposing of the cuttings and fertilising – in a single step. It’s easy on the environment and your wallet.

Advantages of mulch mowing

A long-term experiment at the University of Natural Resources and Life Sciences in Vienna has demonstrated that mulch mowing brings significant advantages and stimulates lawn growth. Over the course of four years, a 1,000-square-metre lawn was mowed with a standard lawn mower and the cuttings disposed of; the lawn was also fertilised with a mineral fertiliser. At the same time, a separate area of the same size was cultivated using a mulching mower, with the cuttings left on the ground. The results speak for themselves:

• The grass was consistently denser and more luscious after being mulched 21 times per year over the entire vegetation period.
• Mulch mowing proved to be more effective than four applications of a mineral fertiliser to the reference area.
• In terms of quantity and ratio, the nutrients that were returned to the soil corresponded exactly to the requirements of the living grass.

Why is mulch mowing growing in popularity?

1. Mulching as you mow means less matting and thatch because the grass itself can grow better. A well-nourished lawn has no room for weeds and moss, so it stays looking perfect.
2. If you have a lawn that grows healthily, you can expect around 1.5 to 2 kg of cuttings from each square metre per year – if you have a 1,000 m² lawn, that’s 1.5 to 2 tonnes! Disposal of green waste is another aspect to consider, and another benefit that mulching offers.

Mulching mowers – simplify gardening, improve lawn health

Less is more – that’s certainly true of mulching your lawn. When you use a STIHL mulching mower, you won’t have to empty the collection box or dispose of clippings, and there’ll be less need to fertilise the lawn too. Mulching resupplies your cut grass’s nutrients back to the soil, which means you have more time to spend elsewhere in your garden while knowing your lawn is getting exactly what it needs.

RM 4 RV
The STIHL RM 4 RV petrol lawn mower is a real mulching expert. The specially shaped mulching blade progressively cuts the grass into small particles, which are distributed as mulch on the lawn, thereby supplying vital nutrients.

Other recommended products:

• RM 4 RV
• RM 650 V
• RMA 448 TC with mulching kit

Mulch mowing tips

To achieve the very best results when mulching your lawn, it’s important that the grass cuttings stay on the surface of the lawn. Make sure there are not too many cuttings and that they are finely chopped and evenly distributed. The nitrogen they contain will be quickly mineralised and made available to the grass plants. Follow our tips to get the most out of mulching your lawn:

• If you mulch mow your lawn, cut the grass more often.
• Make the job easy with a special STIHL mulching mower. It finely chops up the cuttings so they are mineralised quickly, and it scatters them evenly. Alternatively, you can buy a STIHL mulching kit that makes it possible to convert most standard lawn mowers into garden mulchers.
• When mowing, you should cut the grass by around a third of its height – less if the weather is very dry.
• Mow when the grass is dry if possible. If you have to mow when it’s damp, move a little slower and set a higher cutting height.
• Always use the highest speed setting (full power) and make sure the blades are nice and sharp.
• Check the mower housing on a regular basis and clean off any grass residue.
• Make sure you overlap the lines as you mow, so you don’t miss any strips.
• Mow very long grass in stages over multiple days.
• Vary your mowing direction. This will mean that the grass is collected more effectively and the mulch clippings will be distributed more evenly.

Garden shredders for mulching waste

STIHL garden shredders make it easy to quickly bring order to your garden. They have powerful cutting systems that transform woody and soft garden waste into valuable mulch or compostable material in no time.
Recommended products: GHE 250, GHE 355 and GHE 140 L

Summary: what is mulching?

• Mulching is the process of applying shredded plant matter or other material as a loose layer on top of the soil
• Mulch protects the soil and returns nutrients to it as it breaks down
• Create your own mulch using normal garden waste
• Make sure you use the right mulching material for the different areas of your garden
• Mulch mowing cuts grass, finely chops the cuttings and scatters the particles directly onto the ground
• Studies have shown that mulch mowing saves time and money and is good for the environment