Do you also have the problem that lawn clippings do not decompose properly on your compost pile? Here is what you need to do to make sure it composts optimally.
If you just throw your lawn clippings on the compost after mowing, the cut grass develops into a foul-smelling mass that often hasn’t decomposed properly even after a year. The garden waste underneath often doesn’t decompose properly either, and the uninitiated amateur gardener wonders what exactly went wrong.
Fermentation instead of rotting
The reason for unsuccessful composting is quite simple: Organic waste needs good aeration, i.e. oxygen, so that it can decompose completely. If the bacteria and fungi that are important for decomposition cannot breathe undisturbed, they gradually die off. Various microorganisms that have adapted to life without oxygen then take over. These are, for example, lactic acid bacteria and various yeast fungi, which are also used for alcohol production. However, they are not able to completely decompose the garden waste, but only break down certain sugars and proteins. This produces, among other things, putrefactive gases such as methane and hydrogen sulfide, which smells like rotting eggs.
Composting lawn clippings with shrub cuttings
The trick to good decomposition is to ensure a good oxygen supply, so the lawn clippings should not become too compacted on the compost. Experienced amateur gardeners achieve this by adding lawn clippings to the composter in thin layers, alternating with coarser, airier waste such as shrub trimmings. Another tried-and-true method of composting is to mix the lawn clippings with chopped branches and twigs. Grass and wood clippings are basically good partners in compost because branches and twigs provide good airflow due to their coarse structure, but they don’t contain much nitrogen , another factor that slows down the rotting process. Grass clippings, on the other hand, are rich in nitrogen but low in oxygen. The mixture of the two therefore provides ideal living conditions for the microorganisms.
Store chipped material for mixing
Of course, you don’t have the required amount of chipped shrubbery cuttings on hand every time you mow the lawn to make the perfect waste mix, so it’s smart to take precautions: if you’ve pruned and chipped your fruit trees and ornamental shrubs in the fall or winter, you should first store the chipped material in a separate pile next to the composter and then gradually mix it in with the lawn cuttings that accumulate over the course of the season. In this way you get perfect, nutrient-rich garden compost. It is also largely free of weeds and pests: the rotting temperatures can rise to well over 60 °C / 140 °F when mixed optimally, and at such high temperatures all undesirable components are killed off.