Can peat moss be mixed with soil? The simple answer is yes it can, and it can help bolster the soil to create an effective environment for plants to grow.
This article explores the benefits of mixing peat moss with soil, how to mix peat moss with soil, and alternatives to using peat moss in soil.
First of all, it’s worth exploring the basics: what is peat moss?
What is peat moss?
Peat moss is composed of multiple layers of decomposed plant remains, including sedges, reeds, mosses, and grasses. It can take thousands of years to form, and usually occurs in boggy wetlands in the northern hemisphere. The reason it thrives in these areas is that they are a water-heavy environment and oxygen is often limited, which affects the natural processes of decay.
Sphagnum moss can commonly be found on top of peat moss, however this growing plant should not be mistaken for peat moss. Dried, bright green versions of peat moss are commonly used for the base within a hanging basket.
Why mix peat moss with soil?
Peat moss carries some significant benefits compared to compost, one of which is that it is extremely resilient when it comes to breaking down, which means you won’t have to apply it to your garden every year. Here are some other key benefits of using peat moss in your garden.
It can take thousands of years to form, and usually occurs in boggy wetlands
Peat moss is resilient
Peat moss takes a significant time to break down, so you don't have to apply it every single year. What’s more, it avoids the scenario of having other plants grow from the soil, as it doesn’t consist of the seeds of other plants. Some compost mixes or fertilisers don’t always break down the seeds of plants, which isn’t the case with peat moss.
Peat moss retains nutrients effectively
Certain soils allow water to pass through quite freely, which will often happen when they get watered or succumb to rainfall. When the water passes through them, so too do the vital nutrients needed to sustain plant growth. Peat moss helps fertilizer remain more compact and thus retain the nutrients that would otherwise wash away.
Peat moss aids water management
Peat moss is adept at retaining water, which prevents soil from becoming waterlogged as the peat moss releases the water slowly instead. The flow of water therefore becomes natural, and isn’t so slow that you run the risk of drying out your garden. It also avoids potential damage waterlogged soil can cause to plant roots.
Peat moss improves soil ventilation
Soil that is treated with better aeration avoids risk of compaction and impeding root growth. Soil with good ventilation also has a better flow of oxygen and air particles needed by plants in order to produce energy and survive. This means peat moss can be a great addition to a potting mix as it keeps the soil bed sufficiently ventilated, hydrated and stocked with plenty of nutrients. Best of all, you only need to add a relatively small mixture to your potting mix in order for its positive effects to take place.
This leads us nicely onto our next section: how to mix peat moss with soil.
How to mix peat moss with soil
As an example of a good mixture, I would recommend mixing one third peat sphagnum moss with one third compost and one third vermiculite.
When you come to pour the peat moss over the soil, aim for one inch or more depending on your till depth. It’s also important to remember to rotate and turn the soil so it thoroughly combines the peat moss with the dirt.
For plants with deep roots, such as shrubs, you should aim for a deeper tilling, mixing 10 to 12 inches of soil with the peat moss. Then for annual plants and those with shorter roots, aim for a shallow tilling.
This mix of peat moss and soil will create an effective bed of aeration for the soil and help nutrients pass through it effectively.
Alternatives to peat moss
Using peat moss to cultivate gardens has generally only been popular in the last two decades or so. In fact, some gardeners such as myself now find it a necessity. But it’s worth considering the alternatives and methods that existed before the popularity of peat moss - especially since the peat itself takes so long to form from its natural habitat of boggy wetlands.
Compost can take a fair amount of time to produce organically, plus it’s susceptible to more compaction than peat. However, it can still be an effective option for maintaining soil density and drainage.
If you do have the time and perseverance to make your own compost, I recommend using coffee grounds, fruit and vegetable leftovers, and crushed eggshells. For those who own an allotment that houses herbivores, you could even use their manure and combine it with straw to create a compost that rivals peat moss. The manure helps to create a light and aerated compost by breaking down the straw’s fibres.
Perlite is available from many gardening suppliers and online stores. It’s often cheap to buy and, although non-renewable, helps keep soil aerated,retains water and controls nutrient flow.
The product itself is actually derived from volcanic rock. It looks like miniscule foam balls, and has particles which have small cavities on their surface. These cavities have air passages which help achieve all the benefits just listed.
Similar to perlite, vermiculite is an effective product that helps soil retain water and minerals thanks to what it’s produced from: super-heated aluminum iron magnesium silicates. The heating process causes vermiculite to expand, which in turns increases its ability to absorb water.
Leaves, mulch and sand
Dried leaves and even wood from a chipper can help increase soil aeration. What’s good about these is that they’re natural, with no added chemicals which may damage the soil.
Sand can even help with soil drainage - just pour a very fine layer on the topsoil. Sand tends to work well for vine fruits and vegetables, and particularly watermelons if you’re an exotic grower.
An eco-friendly alternative to using peat moss in soil, coconut coir is effective at absorbing water and aiding drainage since it helps to lighten the soil. Once considered a waste product, coconut coir is made from the fibers of coconut shells, making it a sustainable option.