Fallen leaves on the lawn: removing & composting leaves

As autumn arrives and the leaves begin to fall, lawns can quickly become a colourful carpet of foliage. To prevent any damage to the grass, any fallen leaves should be swiftly removed. Read on to learn more about composting leaves and the beneficial uses of fallen leaves.

Clearing up the fallen leaves in autumn can seem quite a chore, especially if there are many trees in the garden. If you are wondering if you really need to remove them from any lawn areas or do fallen leaves kill grass, the answer is, unfortunately, yes. However, there are ways to make this task easier and the collected leaves can be surprisingly beneficial to the rest of the garden.

Do leaves kill grass?

Sadly, any fallen leaves left on a lawn, even for a short time, can be detrimental to the health of the grass. Unless the temperatures dip below 5 °C, grass continues to photosynthesise and grow throughout the winter, requiring light and air to do so. If left on the grass, any fallen leaves can prevent the necessary sunlight and oxygen from reaching the grass. This essentially suffocates the grass, leading to bare patches.

In general, fallen leaves can be left on a lawn for a week or so without leading to any serious damage. However, to prevent a mass of leaves from accumulating and the clearing of them from becoming more onerous, it is a good idea to reach for the rake more often.

Ways to remove leaves

Thankfully, the humble rake isn’t the only tool available for clearing leaves from a lawn. You can also use a lawn mower or leaf blower for collecting leaves. Despite being noisier, these can save a lot of time and effort. However, nothing quite beats the aerobic winter task of raking up fallen leaves.

When raking leaves, a specific leaf rake with a wide fan-shaped set of tines is by far the best choice to minimise time and effort. Using a light motion to avoid damaging the grass, rake the leaves into piles when dry, as damp leaves tend to stick to the tines, making the process far more difficult. Although effective for smaller areas, a rake is often unsuitable for greater lawns.

A leaf blower or vacuum, on the other hand, makes light work of larger areas and is easier on the back. Although noisier and requiring petrol or electricity to power them, leaf blowers and vacuums will make blowing leaves into piles to collect or vacuum up a breeze. However, leaf blowers only prove effective when strong winds are absent and should be used with suitable eye and ear protection.

Fallen leaves can also be collected surprisingly well from grass by using a rotary lawn mower with a collecting bag or box. Simply set the cutting height slightly higher and mow the lawn as usual. Leaves can be used for making leaf mould or adding to the compost heap. As with a leaf blower, remember to wear suitable PPE, and remove any sticks and branches from the lawn beforehand. When using this method, it is important to collect the shredded leaves. Do not leave them on the grass, as this defeats the objective.

Ways to dispose of leaves

Once collected, you can dispose of the leaves in several different ways. Although a popular method in the past, burning leaves is now discouraged, as allowing them to decompose or to provide some winter shelter for wildlife is far more environmentally friendly. However, burning leaves is still permissible, as long as the smoke produced does not affect any motorways or prove a nuisance to neighbours.

If garden space is limited and composting leaves on site is not an option, you can take the collected leaves to your council’s green waste bin or to the garden waste section at the tip. Even though the leaves decompose, disposing of any leaves or other garden waste in the countryside is considered fly-tipping and illegal.

Recycling leaves to make leaf mould, compost or mulch

There are a few beneficial ways of recycling fallen leaves around the garden. You can allow leaves to break down slowly on their own by the action of fungi to make leaf mould. Alternatively, you can add leaves to a compost pile or to beds or borders as mulch.

Making leaf mould

Formed by leaves decaying over time, leaf mould is a precious soil conditioner that you can even use as a growing medium. To make leaf mould, store leaves in bin liners or wire mesh cages and leave to rot down. When using a bin bag for leaf mould, slightly wet the leaves first to speed the up process and make air holes in the bag before tying up lightly. After 1 year, you can spread the leaf mould on the soil as a conditioner or mulch. If allowed to fully decompose over 2 years, you can use it as a low-nutrient seed sowing seed medium.

Making compost from leaves

Adding fallen leaves to a home composting system is another way of recycling them, although this may require more thought. You can learn all you need to know and the different methods available in our specialist article on home composting. As collected leaves can form a damp and airtight layer in the compost pile, it is best to chop up or shred any leaves for composting with a lawnmower before adding them. Shredding the leaves and turning the compost regularly will help speed up the decomposing process and help provide the necessary air circulation.

Compost accelerators which contain bacteria, nitrogen or lime, can be added to raise the temperature and speed up the composting process. Once fully decomposed, garden compost is perfect for adding to flower and vegetable beds and refreshing pots and containers.

How to make leaf mulch

You can also apply any collected leaves to beds and borders for winter protection or as a soil conditioning mulch. To protect the soil from the cold, spread whole leaves on the soil in a layer 4 to 6cm thick. Since entire leaves take a long time to rot down, you should remove them in spring to make way for new growth to appear.

Shredded leaves also provide an insulating layer, but are also beneficial as they rot down into organic matter much faster and help fertilise the soil. However, mulching purely with leaves can lead to nutrient deficiencies during the rotting process. You can learn more about mulching and its benefits in our separate article.

What are the best leaves for making compost?

All leaves will eventually break down. However, some leaves decompose far more quickly than others and are better for composting and making leaf mould and mulch. Ash (Fraxinus spp.), beech (Fagus spp.) and hornbeam (Carpinus spp.)leaves are low in lignin fibres and break down quickly without any assistance, typically over a year. Composting laurel (Prunus laurocerasus), magnolia (Magnolia spp.) oak (Quercus spp.) and walnut (Juglans spp.)leaves takes longer and they should be shredded before adding to the compost pile.

The stunning silk tree’s (Albizia julibrissin) fine foliage is easy to compost, but it is only moderately hardy and can only be grown in warmer parts of the UK.