Sphagnum Moss: What It Is and How to Use It

Sphagnum moss is one way to retain moisture in potted plants, and its stringy, fibrous nature makes it an attractive option for hanging baskets. However, confusion exists as to the difference between sphagnum moss and peat moss (sometimes referred to as sphagnum peat moss). The origin of these two popular soil amendments is similar, but how and why you would use each one may differ. Learn more about sphagnum moss, what separates it from peat moss, and the best uses for each.

What is Sphagnum Moss?

Sphagnum moss, which is a genus of mosses with 380 species, is not a moss plant that you grow in your garden, it is a horticultural product. Most sphagnum moss you would find in your local store is harvested from wetlands or bogs found in the Northern Hemisphere.

Both sphagnum moss and peat moss are dead, dried material from the sphagnum moss plant. Sometimes small bits of other plants, including grass, sticks, and vines may be mixed into the products but this does not affect their quality and performance. They are well-loved by gardeners and artists for both soil amendments and arts and crafts. But which one should you use for potting purposes, and which one is better for amending garden soil?

Sphagnum Moss vs. Peat Moss

Since sphagnum moss and peat moss both come from the larger genus of sphagnum moss, they are technically the same plant. However, it is how they are harvested that distinguishes the two.

Peat moss is harvested by collecting the dead moss debris from the bottom of the bogs and wetlands where the sphagnum moss grows. This means that this dead moss material is also mixed with other decayed plant and insect material, making it extremely rich in organic nutrients. In fact, the peat moss found at the bottom of bogs can be thousands of years old!

Sphagnum moss is collected from still-living moss on the surface of bogs and wetlands. These chunks of living plant material are dried after harvesting, making the final product a pure chunk of the sphagnum moss, not a combination of other dried material.

So, while very similar, sphagnum moss and peat moss have some key differences in terms of their composition.

For general soil amendment, peat moss is the best choice. It can easily be found in larger bags and is less expensive. Besides being more cost-effective, the wide range of decayed matter in peat moss makes it a great soil amender for both potted plants and the garden. Mixing it with sandy soil will help hold onto needed moisture that may otherwise drain away. Mixing it into clay soil will help loosen the soil and allow it to drain better.

In addition, keep in mind that peat moss has a very acidic pH level while sphagnum moss has a neutral pH level. The pH level of your plants and soil will play an important role in determining whether sphagnum moss or peat moss is the better choice for your gardening purposes. Obviously, acid-loving plants will appreciate peat moss being used as a soil amendment, especially when soil is particularly alkaline.

How to Use Sphagnum Moss

Sphagnum moss is useful for a variety of gardening and crafting purposes; however, its higher cost and less diverse organic matter make it a better fit for speciality purposes.

You'll often see it used for creating a Kokedama (which is a moss ball planter), seed starting, as a planting medium for orchids, as a potting soil amendment, for lining baskets, or for other art projects.

It has a neutral pH level and is great for retaining moisture in the soil, even when dried. It is often found in smaller bags in both craft stores and garden centers. In addition, live sphagnum moss is a popular choice for terrariums.

Some of the key reasons for using sphagnum moss are outlined below.

As a Soilless Potting Medium

Sphagnum moss is commonly used when growing succulents or orchids indoors. It is light and holds moisture very well. It doesn't become overly soggy though, so it means your plant is less likely to be bothered by root rot issues.

Depending on the plant, it might be used on its own or mixed with soil or another potting medium. On its own, waterings may need to be more frequent and fertilizers may be required as sphagnum moss does not hold much in the way of nutrients.

As a Liner or Form Builder

The soft, light, pliable form of sphagnum moss makes it a popular choice for lining hanging baskets or for using to create and hold the shape when making up succulent wreaths or other frame-built floral displays.

For Decorative Purposes

When used in container planting, sphagnum moss isn't just practical, it can also be decorative. It can enhance the finished look of a pot, basket, or terrarium, and helps to fill in dead space.

Quality and Sustainability of Sphagnum Moss

Sphagnum moss is considered to be more sustainable and environmentally friendly than peat moss. Peat moss can take centuries or more to develop and be ready to harvest, whereas sphagnum moss is ready to harvest in under a decade. When sourcing your sphagnum moss it is still recommended to look for a reputable and sustainable supplier.

Sphagnum moss can vary significantly in its ability to absorb moisture, the quality and length of the fibers, and its appearance. Take the time to research suppliers with good reputations.

Keep these important points in mind the next time you're perusing the garden center or nursery to avoid becoming bogged down in your moss options.

If you want to add a decorative, yet functional feature to your hanging baskets, reach for sphagnum moss. For the purposes of soil amendment, use peat moss or coco coir as a sustainable alternative.