If you are preparing your garden beds during the next few weeks, you should consider mulching. Many Haines gardeners mulch with seaweed over the winter, but keeping your beds mulched year-round can bring many benefits, leading to less work for you in the long run while creating healthier soil.
Mulch can be factory made plastic or weed block, but it can also be a range of organic materials, which can be free of cost and will yield more benefits to the microbes in your soil.
Some of the benefits of mulching include increasing water retention in the soil, meaning you can water less frequently, or potentially not at all depending on the weather. Mulching with the right material also helps suppress weeds, which means less time weeding, and more space for your plants’ roots and leaves. Most importantly, healthy veggies and flowers require healthy soil, and mulching is a great way to continually feed organic material to your soil.
One of my teachers described an old growth forest as the pinnacle of healthy soil. And one thing to note about this soil is that it’s almost always covered in organic materials– whether that be fallen leaves in a deciduous forest, dead trees or branches, rotting plants, mushrooms, moss or any other type of ground cover. As this material decomposes, microbes and fungi in the soil feed and breed, which creates more life in the soil, ultimately leading to larger, happier plants.
To model the garden after a forest, we must strategically choose what materials to mulch with, and how much to use. For example, mulching too thick with nitrogen rich materials like grass can lead to mold or anaerobic bacteria, which is not the goal. Thin layers of nitrogen- rich materials (green leaves) and thicker layers of carbon-based materials (brown leaves) is comparable to turning your garden bed into a slower version of a giant compost. This is a simplified way to think of mulching in layers as an effective method. In Haines, we are lucky to have so many organic materials readily available to mulch with. Here are just a few examples:
Seaweed provides a good source of nitrogen, as well as many other trace minerals important for plant growth including magnesium and potassium. Newspapers or brown corrugated cardboard can also be used, which are great weed suppressors and provide a source of carbon. Wood chips (not sawdust) and fall leaves are also a good source of carbon, which will encourage fungal growth. Mushrooms are generally a good indicator of healthy soil. The mycelium portion of the fungus spreads underground and allows nutrients to be exchanged more easily from one plant to another. All of these materials can be put directly on top of your soil (not mixed in) over winter and around the plants throughout the growing season.
There are a few things to be aware of when mulching. If you are seeding directly into the soil, you may want to wait to mulch until after your plants have germinated, as the mulch can inhibit those seeds from growing. Certain mulches combined with certain conditions (especially during very wet years) can lead to more pests like snails or slugs. However, in time, the predators that control these pests should also increase. Using contaminated mulch will result in those contaminants leaching into your soil. Likewise, mulching with materials that contain seeds will spread those seeds throughout your garden, so make sure to choose your materials carefully. Lastly, if harvesting naturally occurring organic material to mulch with, do not take all of it, as it’s usually a habitat for some smaller creatures.
If you want to learn more about mulching, there’s lots of information available online. As with most things in the garden, you can always experiment by mulching some beds and comparing them to beds that are not mulched. If you start seeing an increase in earthworms or mushrooms, you’re doing something right.