Twigs and sticks are an inevitable part of yard waste added to composting feedstock. They make up the browns of compost, and they are a critical ingredient for a healthy compost heap.
It takes 4-6 weeks for twigs and sticks to compost in a hot composting unit and up to several years in a cold composting unit. The decomposition rate of the twigs and sticks depends on the size of the pieces, aeration, moisture, and fungal growth inside the pile.
This article will explain why twigs and sticks take so long to compost and how you can help the process along so your twigs break down faster. I’ll also examine the role that twigs and sticks play in composting so you understand why you should leave them in even if they take more time to decompose, so read on!
Why Browns Take Longer to Compost
Yard waste comprises grass clippings, dried leaves, twigs and sticks, and woodchips. In contrast, the grass clippings and food scraps are rich in nitrogen and make up the greens in your composting feedstock.
Dried leaves, twigs and sticks, and woodchips make up the browns in your composting feedstock. These browns are rich in carbon, which composting microbes use for energy. However, carbon is processed much slower than nitrogen sources.
Additionally, plant materials like wood chips, twigs, and sticks have higher concentrations of carbon compounds, lignin, and cellulose when compared to dried leaves. These compounds, particularly lignin, are difficult to biodegrade, and the presence of lignin in plant material slows the decomposition process significantly.
Often, compounds like lignin and cellulose cannot be decomposed by the bacteria alone. Fungal activity is required to break twigs and sticks down entirely into the uniform humus that makes up a healthy compost.
While the greens in your compost may be fully processed into humus by the time the second stage of composting begins, which is the thermophilic stage, the browns take much longer.
Twigs and sticks start to break down in the initial mesophilic composting stage. The microbes and fungi continue breaking them down throughout the three stages of composting.
This slow degradation is part of why partially decomposed compost is unusable – because the lignin and cellulose are half processed and need a longer cooking time before they integrate with the composted humus.
How Do You Break Down Twigs in Compost?
Generally, carbon sources like dried leaves, twigs and sticks, and woodchips take much longer to decompose than nitrogen sources like kitchen scraps.
To break down twigs in compost, you should break them into smaller pieces to make it easier for the bacteria to eat them. Maintaining the right temperature and moisture in your compost will also help break the twigs down.
You may also want to encourage fungal growth as fungi can break the lignin and cellulose down faster.
It is important to remember that even when you manage your browns correctly, they will need at least a few weeks to break down in a hot composting unit due to the time necessary for lignin to biodegrade.
Break Them Into Smaller Pieces
It’s a good idea to shred your compost scraps, whether you’re storing them in the freezer or adding them directly to your pile, and the same is true for browns like twigs and sticks.
Breaking the organic material down into smaller pieces reduces the overall time needed for decomposition because the smaller size makes it easier for the microbes to use it up. It’s just like chewing up your food!
While you can easily tear kitchen scraps and grass clippings into small pieces, you might want to consider investing in a shredder if you have a lot of twigs and sticks to add to your pile.
Most domestic use shredders can break down twigs and sticks that are slightly over an inch into smaller pieces, which you can add to your compost when layering the browns.
Maintain the Correct Temperature and Moisture Levels
High temperatures and adequate moisture are essential for the decomposition of lignin and cellulose. That is why hot composting is better for breaking twigs and sticks down completely.
To maintain high temperatures in your compost, you need to ensure that the balance of browns to greens is correct and that your greens are rich in nitrogen.
If you find that the pile is still cold, despite maintaining a 3:1 ratio of browns to greens, you might consider adding cow or chicken manure to your compost, as these are rich in nitrogen. Another good source of nitrogen that might be more accessible is coffee grounds.
Covering your compost is an excellent way to insulate your pile, especially if your composting unit is on the smaller end.
Moisture is equally essential in maintaining temperatures. Insufficient moisture will make the pile too hot, killing off the organisms that decompose the organic matter, thus halting the process entirely. Additionally, twigs and sticks absorb water, which helps break down the cellular structure and aids decomposition.
Encourage Fungal Growth
You may see white powder on your compost if you have a lot of twigs and sticks in your pile. This powder is likely fungal growth, as fungi support aerobic bacteria in breaking lignin and cellulose down. Fungi can also break down the browns faster than the bacteria.
Unless the growth is excessive and affects how you can handle the pile, leave it alone, as the fungi will help your twigs compost faster. Still, wear gloves and a mask when handling fungus to protect yourself from falling sick because of the compost.
Role of Browns in Compost
Browns form the carbon in composting, and carbon is a vital energy source. That means that twigs, sticks, and branches are an essential fuel for the bacteria that process the composting feedstock and break it down into compost.
Maintaining the carbon-to-nitrogen ratio is crucial whether you’re composting with or without a bin to ensure a healthy compost that decomposes quickly. Too much nitrogen can result in a hot mixture that burns the composting feedstock.
Apart from being a vital energy source that fuels the microbes during the composting process, twigs, sticks, and other carbon sources have other benefits that keep your compost heap healthy:
The microbes that result in aerobic decomposition in a compost pile need oxygen to survive. While composting is possible with anaerobic bacteria, the process typically takes longer, releases toxic compounds and gasses, and smells pretty terrible while it’s happening.
Anaerobic decomposition is also a cold process, which means that the end product won’t be sterile and easy to handle like the compost made out of aerobic decomposition.
While turning the heap to aerate your compost is an essential activity in introducing fresh oxygen to your compost pile, you can help the process by adding browns like twigs and sticks.
Twigs and sticks are bulkier, more rigid materials that take a long time to break down, making them perfect for breaking up the finer particles of compost and creating air pockets to help the aerobic bacteria thrive.
The lignin in twigs and sticks is also known to be a porosity enhancer, so when the twigs do eventually break down, they improve the overall aeration of the compost pile.
The browns in the compost play many roles, but the most important is maintaining the moisture levels in your compost pile. Your compost shouldn’t be too wet or too dry, as both of these situations impact the decomposition process and slow it down.
The greens in your feedstock are a source of moisture. However, depending on the composition of your feedstock, you may also need to water your compost regularly to keep the microbes hydrated.
The browns in your compost will absorb excess moisture, which helps them decompose. Extra water absorption supports your compost by ensuring that your aerobic bacteria do not drown. It will also ensure that pests and scavengers are not attracted to your compost.
Soggy, wet compost tends to be highly smelly and will attract pests like fruit flies and white worms and scavengers like rats and even bears if you live in bear country.
Bulk and Texture
The ideal ratio of browns to greens in compost is about 3:1 to ensure that the browns fully cover the greens and supply the necessary energy to the microbes processing organic matter. As a result of this ratio, the browns also provide bulk and texture to your compost.
The twigs and sticks in your composting feedstock allow your compost to be crumbly like moist soil rather than the sticky mess it would be if the pile were heavier on nitrogen. Large clumps of nitrogen heat up too fast, killing the bacteria, then turn cold, resulting in a cold congealing mess of decomposing food scraps. The browns give your compost a fluffy texture while adding lightness through aeration.
Twigs and sticks take about 4-6 weeks to compost in a hot composting unit and even longer in a cold composting unit as the lignin and cellulose in the plant cells take a long time to break down. Shredding them and maintaining high heat and moisture levels, and encouraging fungal growth will help you break down twigs in compost.
Despite the extended period, adding twigs and sticks to your pile is crucial as they aerate, maintain moisture levels, and add bulk to your final compost humus.