Organic Mulches

When planting trees, crops or other plants, one important thing to look into is mulches. With so many different options to choose from it can be hard to tell what to use but thankfully, this guide should give you a little insight into what to choose when planting your garden. It is important to understand however, before starting, that what type of mulch you use is highly dependent on where you live, what you are growing and the type of soil you are working with. This is just a general guide and should be used to help determine your own needs.

To start with, if you are a complete novice and don’t even know what organic mulch is, organic mulch is just decomposing plant matter that you mix with the soil to help provide nutrients, stability, insulation and water retention. It can also deter pests and is usually incredibly cheap as it is just refuse that you would have thrown away anyway. The interesting part about it is the amount of variety you can have using different mulches and the different benefits that can be gained that are unique to each mulch type. While this doesn’t cover every type of mulch, it gets the general idea and includes a few ones you wouldn’t really think of.

The first one to look at is bark. Shredded bark comes in many varieties, sizes and is great for trees as it provides stability, holds water really well and returns nutrients back to the soil as it decomposes. This can be in small shreds or larger pieces and is a great way to make trees stand out as it gives them a natural pleasing look. It is important, however, to leave these on top instead of mixing them with the soil as it will lose the insulation and water retention.

Next, municipal tree waste is another great option. It is usually free to everyone and looks really good if you arrange it right around the tree but it does have a few downsides. Because it is fresh mulch and isn’t aged at all, it will consume nitrogen as it decomposes. For plants where nitrogen is a limiting factor for growth, it shouldn’t be used but some plants don’t need this nutrient as much. For this one, it is really important to look at what plant you are planting and what it specifically needs for growth. It is also not going to have any real label of what type of wood it is or if there are additives which can cause bad interactions with your plant but for free mulch, it isn’t the worst option. Usually this is used as decoration as it can look nicer than the aged bark mulch.

Next, we have cocoa bean hulls. While this may not be an option in some places, for others it can be great. It is a byproduct of getting cocoa beans and are usually discarded after roasting the bean out of the shell. Through the roasting process, it sterilizes the shell of any pests so it is usually going to be a safe option. They also can have a nice smell to them and will look nice surrounding your plants. To use, don’t put more them more than 1” deep and water them lightly. Despite this, it can have a few major drawbacks. Because it is roasted, it needs to be reapplied yearly as it decomposes quite fast. It can also be a problem for any pets you have as cocoa is toxic to most household pets so it is important to take into consideration before buying.

Another mulch, that is common to most areas and usually free, is leaves. While it may not look as attractive as commercial mulch, it is incredibly easy to find as long as you live in an area that has seasons. It also is incredibly nutritious for the plants as leaves contain around 80% of the plants nutrients (carbon, potassium and phosphorus). It also feeds earthworms and can lighten heavy soils like clay. The only thing to remember is to shred or compost these as whole leaves will stop rain water from reaching the soil and eucalyptus leaves are not useful in this kind of mulch.

Another free mulch is grass clippings. This can be a great mulch as it decomposes quickly, is free as long as you have a lawn or know someone who does and near the end of the growing season, can help replenish nutrients for the next year. To best use them, it is important to use dry thin layers of grass as wet, thick clippings tend to smell really bad while decaying. This is perfect for vegetable or flower gardens as they are easy to obtain and contain a lot of nitrogen which is used in seed growth. The only thing to watch is if the grass has been treated with chemicals or if they are seeded grass clippings as this will contaminate the soil or start growing grass in your garden.

Often overlooked, newspaper shreddings are also a great way to reuse old newspaper. It is often thought that the ink will be toxic but lead hasn’t been used in newspaper ink in a long time so as long as you use black and white sections of newspaper with no color or slickness to them which contain heavy metals, you will be fine. It is also good to use for keeping plants warm and keeping weeds at bay but can look unattractive to some gardeners. To help this, you can mix newspaper and another mulch type to hide the newspaper.

Another that you may not think of, is straw. It looks good, controls weeds, adds nutrients and can be a good way to regulate soil temperature and direct sunlight on plants as its light color reflects instead of absorbs. It is easy to use as well and can be mixed into the soil to add nutrients before planting. It does have some drawbacks though as straw from meadows can have seeds mixed in and can be a good haven for pests like rodents and small mammals.

Last, compost is a great way to recycle old food and keep nutrients available for the next growing season. Especially if you are an organic gardener, this can be a way to know exactly what is in the mulch which can be an attractive offer to some. Manure is a type of compost but it does tend to smell and can be expensive unless you have livestock as well. The easiest way to compost is to just use any food scraps or yard waste and allow it to rot over the winter then mix into the soil before planting.