The Best Soil for Orchids: A Complete Guide

Orchids are the epitome of elegance and exotic beauty, with their delicate blossoms and vibrant colors. However, to ensure their healthy growth and longevity, it’s crucial to choose the right soil for these tropical plants. Ordinary potting soil is too dense and compact for orchids, hindering their development. In this article, we will explore what to look for when selecting soil for orchids and highlight the top soil blends that promote optimal growth.

What to Consider When Buying the Best Soil for Orchids

Orchids dislike being constantly wet, so the ideal orchid potting soil should facilitate rapid drainage. Before choosing the right soil, it’s essential to understand these plants and their care requirements. Most orchids found in stores today are epiphytes, which means they naturally grow on other objects, like tree trunks and rocky cliffs, where their roots can take hold. Consequently, these orchids struggle in boggy soil because their roots require air access.

Orchid Types

Orchids are generally classified into two types: phalaenopsis and dendrobium. Both types have been hybridized to produce stunning blossoms that can last for weeks, but they differ in some key aspects.

  • Phalaenopsis: Also known as “moth orchids,” phalaenopsis is the most common hybridized orchid. They have a single stem from which all foliage and blossoms grow, with only one root system. Phalaenopsis stems can grow quite tall and require stabilization.

  • Dendrobium: Dendrobium orchids have multiple root systems and produce numerous blossom-bearing spikes. These orchids maintain a lush base of foliage at the soil level.

Organic Orchid Potting Mix Ingredients

Many eco-conscious consumers prefer organic orchid mix as it is free from chemicals. True organic mixes contain only natural and untreated ingredients. To qualify as organic, all components of the potting mix must be organic, certified by the Organic Materials Review Institute (OMRI), a branch of the United States Department of Agriculture (USDA). Common organic ingredients include:

  • Bark: Lightweight and chunky, bark options like fir bark, cedar bark, or pine bark chips encourage drainage.

  • Sphagnum peat moss: This allows for drainage while retaining some moisture. After blooming, repot the orchid in an orchid-growing mix.

  • Coconut coir: This fibrous husk between the coconut shell and the fruit allows water to drain while retaining moisture on its surface.

  • Charcoal: Charcoal absorbs salts and bacteria and is often added to orchid mixes. It’s considered organic if derived from burnt organic materials such as untreated wood or peat.

  • Perlite: A byproduct of volcanic glass, perlite can be organic if it hasn’t come into contact with chemicals during processing.

Inorganic Orchid Potting Mix Ingredients

Inorganic mixes contain natural ingredients like bark or coconut coir but also include other components that prevent them from being certified as organic. They may also contain synthetic fertilizers to enhance plant growth. Common inorganic ingredients include:

  • Leca: Lightweight, expanded clay aggregates that absorb and release water slowly. Excessive amounts can cause the soil to retain too much water.

  • Seramis: Another clay product that absorbs and releases water slowly.

  • Charcoal: When derived from non-organic materials, charcoal is considered inorganic. It can still be beneficial in orchid soil mixes.

  • Lava rock: This porous rock prevents soil compaction and absorbs excess water, providing a structural base for moth orchids’ roots.

  • Fertilizer: Synthetic or chemical fertilizers may be present in certain orchid mixes to enhance plant health.


While low-growing orchids don’t require support, popular phalaenopsis varieties cannot stand upright without some form of stabilization. Typically, moth orchids come with supports like bamboo straws, wood dowels, or plastic spikes already in place. When repotting, insert supports in the new soil to stabilize the stem. For a more artistic look, natural branches can also be used. Gently tie or attach the orchid stem to the support to ensure stability.


Orchid roots thrive when allowed to slightly dry out between waterings. In their natural habitat, orchids grow on tree trunks in tropical forests, with roots partially exposed. To mimic this damp/dry cycle, orchid soil mixes often contain perlite, vermiculite, lava rocks, and other chunky materials. The best potting soil for orchids should remain light and loose over time, providing an airy environment for root growth.


In addition to well-draining soil, it’s essential to plant orchids in pots that encourage proper drainage. Orchid pots have holes not only at the bottom but also along the sides to facilitate quick water drainage. Unfortunately, commercial orchids are often not planted in the correct pots or soil. After a new orchid has finished blooming, repot it in a suitable container using one of the recommended orchid soils to ensure its longevity.


One common mistake made by new orchid growers is overwatering their plants. Orchids require different watering frequencies depending on the season. During the slow-growth period (fall and winter), water orchids once a week, and then increase watering to twice a week in spring and summer. Properly potted and soil-drained orchids can tolerate varying amounts of water, as it quickly drains away. However, overwatering can become an issue if the orchid is in sphagnum peat moss without drainage holes. In such cases, it’s best to err on the side of caution and provide only minimal amounts of water during regular watering. Some growers recommend using one ice cube per every 2 inches of pot diameter to prevent overwatering. For instance, three ice cubes placed at the edge of the pot in contact with the soil of a 6-inch pot provide sufficient water.

Our Top Picks

To ensure healthy and beautiful orchids, it’s crucial to select soil mixes specifically designed for their growth. The following orchid soil mixes have been thoroughly researched and carefully chosen for their ability to drain well, contain quality ingredients, and retain their structure over time.

Our Verdict

While all the orchid soil mixes in our lineup are suitable for growing healthy orchids, our top pick for overall performance is Perfect Plants’ Organic Orchid Potting Mix. Its organic composition and excellent drainage make it ideal for tropical orchids. For budget-conscious individuals seeking a mix with added nutrients, Miracle-Gro Orchid Coarse Mix is a great choice. It offers aeration, affordability, and a touch of fertilizer.

How We Chose the Best Soil for Orchids

In compiling this guide, we extensively researched numerous orchid-specific growing mixes from well-known garden-product companies and smaller operations. The critical factor in selecting these mixes was their ability to drain rapidly, as slow-draining and compact soil is detrimental to orchids. While we also evaluated all-purpose indoor mixes, they did not make the final cut due to their tendency to retain excess moisture.

For phalaenopsis orchids, we focused on soil mixes that provided structural stability, such as those containing lava rocks. This helps prevent lanky stems from dislodging the roots. Although we gave special attention to certified organic mixes, we also considered high-quality soils made from natural ingredients, even if they were not 100 percent organic.


Orchids have a reputation for being challenging to grow indoors, but with proper care and drainage, they can thrive in most indoor conditions. If you have questions about the suitable soil for orchids, read on for answers to some frequently asked questions.

Q. Can you use all-purpose soil for orchids?

No, all-purpose potting soil or garden soil is unsuitable for orchids as it is too dense and retains water, hindering proper drainage.

Q. Can you use any bark for orchids?

Commercial bark options are generally acceptable as long as they are sterilized. Avoid using bark from trees, as it may contain bacteria, diseases, or insects that can harm orchids.

Q. Can you plant an orchid in dirt?

No, regular garden soil is too dense for orchids and may contain bacteria or insects that could be harmful to the plants.

Q. Are used coffee grounds good for orchids?

No, coffee grounds are too acidic for orchids. They can also contribute to soil density and reduce drainage.

Q. Is bark or moss better for orchids?

Bark is more important than moss. Sphagnum peat moss is used when potting orchids before they are sold, but it retains too much moisture on its own. After the blooming period, repot the orchid in a soil mix with a higher bark-to-moss ratio.

Q. How do you repot an orchid?

Wait until the orchid has finished blooming, and then repot it in an orchid pot with holes or slits on the sides to ensure proper drainage. Use a soil mix specifically designed for orchids.

Q. How often should you water an orchid in bark?

Water orchids potted in bark once a week during the slow growth season (fall and winter), and increase watering to twice per week in spring and summer.

Choosing the right soil for your orchids is essential for their health and longevity. With the recommended soil blends and proper care, you can enjoy flourishing and beautiful orchids in your home.