Does Adding Orchid Bark To Your Soil Make Your Plants More Prone To Mold?

Gardeners often use amendments like orchid bark to improve soil drainage. These DIY potting soil recipes help create a mixture that drains quickly but also maintains an adequate level of moisture. However, orchid bark in particular comes with a major downside. According to Tiffany Selvey, House Digest editor and in-house master gardener, adding orchid bark to your soil can make your plants more prone to mold. As a result, you may want to think twice before using it carelessly. You can, however, reduce the risk of mold growth by pairing orchid bark with other amendments that will absorb excess moisture.

"Almost any organic substance added to soil has the potential to grow mold, and if you're adding orchid bark to a soil mix formulated to retain water (usually a peat-based blend), then it is certainly possible the wood will stay too wet and grow mold," Selvey revealed while speaking exclusively to House Digest. At this point, you may be wondering what orchid bark is composed of. Thankfully, Selvey broke this down, too.

"Orchid bark is simply ground up chunks of wood, usually fir or pine," the master gardener shared. These types of wood are used in high-quality orchid bark because they are particularly good at retaining moisture and releasing it as it's needed, mimicking conditions in nature for epiphytic plants." Keep in mind that orchid bark on its own is not the same as orchid potting mix. According to Selvey, orchid bark potting mix "can contain wood, perlite, charcoal, and possibly peat and fertilizer."

Although adding orchid bark to your soil can lead to mold growth in your houseplants or outdoor garden, you don't necessarily have to avoid it altogether. Tiffany Selvey explained in an exclusive interview with House Digest that she's been able to use the substance successfully. "On its own, orchid bark is unlikely to grow mold," the expert admitted. "I like to add it to some of my soil mixes for plants that need exceptional drainage, like my monsteras, and I've never had a problem with mold growth. That may be because I use other moisture-absorbing substances, like perlite, for my blends, which allows the bark to dry out between waterings."

It seems that the key there is carefully curating your soil mixture. Selvey also stressed the importance of this. "If you are thinking about adding orchid bark to your soil to improve drainage, consider what is in the rest of your potting mix," she shared. Amendments that will absorb extra moisture that could cause mold to grow will help you use orchid bark successfully.

Sometimes, orchid bark leads to mold growth in plant soil when it gets wet inside of soil packaging. When you purchase this soil, there's a chance that you could end up using it for your plants before realizing that mold has already begun growing inside the package. While speaking exclusively to House Digest, Tiffany Selvey shared a tip to help you determine whether the orchid bark in your store-bought soil has been contaminated with mold. 

"If you open a bag and notice a musty smell or the bark is spongy or damp, it's best not to use it to avoid contaminating your soil," she explained. With this information, you now understand how to mitigate the risk of orchid bark molding and harming your plants. There's no need to fear the commonly used soil amendment. You just need to be well-informed before putting it to use. If you've sworn off orchid bark due to a bad experience in the past, consider giving it another try with these tips in mind.