ZZ plants, scientifically known as Zamioculcas zamiifolia, thrive best in a well-draining, porous mix that can retain sufficient moisture to support it. It also prefers slightly acidic soil with low nutrient content.
In this guide, we’ll help you choose the right components for your mix and recommend recipes you can follow to keep your ZZ plant flourishing. But before that, let’s first break down all the things you have to consider when choosing soil for your ZZ plant.
Things to Consider When Choosing Soil for ZZ Plants
Draining Capacity
ZZ plants are native to East Africa and are used to arid conditions, so they do best in warm and dry conditions. This is why well-draining soil is a lot more suitable for them.
They’re very sensitive to overwatering and can easily suffer from root rot if the soil retains a lot of moisture. Choosing a mix with exceptional drainage minimizes the risk of overwatering and allows the roots to access nutrients and oxygen better.
As succulents, they can store water in their stem and tolerate drought. You won’t need to worry about them dying from lack of moisture just because the soil drains quickly.
Aeration
One of the biggest causes of stress to plants is suffocation due to heavy and compacted soil. The roots can’t access oxygen, hindering their metabolic processes and overall growth.
Additionally, roots can’t uptake nutrients from the soil if they’re damaged due to lack of oxygen. This makes it harder for the plant to support every leaf and may sacrifice some to survive.
Aeration comes hand-in-hand with draining capacity. A well-draining mix is likely porous enough to let oxygen reach the roots of your ZZ plant.
Moisture Retention
An ideal potting mix for ZZ plants should be able to retain sufficient moisture for some time to help the plant store enough water in its leaves.
This may sound like it’s contradicting what we said earlier about the soil having exceptional drainage, but it does not. You should choose soil that strikes a balance between moisture retention and drainage.
The soil should be able to hold enough water to help ZZ plants absorb as much water as it can, but it shouldn’t make the soil soggy. Hence, the soil should also be able to let excess water drain away.
Fertility
ZZ plants are adapted to survive in low-nutrient environments since they’re originally from the arid regions of Africa. Hence, the soil mix shouldn’t be highly fertile to avoid shocking the plants.
They’re also naturally slow growers, so there’s no need for nutrient-rich soil to support their growth. They’re more likely to suffer from over-fertilization if you expose them to a highly fertile environment.
pH Level
ZZ plants thrive in a slightly acidic to neutral pH, preferably within the 6.0 to 7.0 range. The roots can absorb nutrients, moisture, and oxygen best around this range.
If needed, you can adjust the soil’s pH by adding some amendments. Sulfur can lower the pH and make it alkaline, while lime can make the soil more acidic and increase its pH level.
That said, a slight deviation from the recommended range won’t cause much harm to your ZZ plant as long as it’s not exposed to it for a long time.
Components of a ZZ Plant Soil
Regular Potting Mix
A regular potting mix will serve as the primary medium and base soil of your ZZ plant. It should be well-draining and porous, have good moisture retention, and have just enough nutrients to support your plant’s growth.
Most indoor potting mixes would work for this since they all typically have good drainage. If you have to choose between a loam-based and clay-based potting mix, choose the loam-based one since it doesn’t compact easily.
Some potting mixes that you can try include Miracle-Gro Indoor Potting Mix, FoxFarm Ocean Forest Potting Soil, and ZZ Plant Premium Potting Mix.
Succulent Soil
Succulent soil is a special potting mix designed to imitate the native growing conditions of succulent plants. It’s typically composed of a mixture of materials that promote good drainage, like sand, pumice, perlite, and vermiculite.
While ZZ plants are considered succulents, this type of potting mix typically drains faster than what they prefer. ZZ plants prefer a slightly more moisturized environment and a bit more nutrients than succulent soil can provide.
Hence, it’s important to modify it with potting mixes or soil amendments with good moisture retention qualities. Some amendments you cause include peat moss and coco coir.
Perlite
Perlite is every gardener’s best friend, especially gardeners growing succulent plants like ZZ plants. It’s a lightweight volcanic glass that improves soil’s structure and makes it more porous and well-draining.
It’s expanded through heating, so it can create bigger gaps in the soil where air and water can pass through. These gaps or air pockets make it easier for the roots to absorb moisture and air, allowing them to develop healthily.
If you don’t have perlite, you can use pumice or coarse sand as an alternative. These two can also improve the soil’s structure, although they’re slightly heavier.
Peat Moss
Peat moss is an organic material commonly found in peat bogs. It’s made of decomposed materials, like sphagnum moss, and can be used as a soil amendment for various plants, including ZZ plants.
It has exceptional water-holding capacity, so it can help your ZZ plant hydrate in between waterings. It also helps improve the soil’s aeration, ensuring the roots receive enough oxygen.
Moreover, peat moss can hold onto nutrients and release them slowly, reducing the risk of nutrient burn on the roots.
Vermiculite
Vermiculite is much like perlite in the sense that they both improve the soil’s drainage capacity and porosity. It’s just slightly heavier and characterized by a shiny, flake-like appearance.
It helps maintain a loose structure in the soil, preventing compaction and root suffocation. It’s also free from pests and diseases that can harm your ZZ plant.
Vermiculites don’t decompose completely like perlite. You can enjoy their benefits for a long time, reducing the need for frequent repotting.
Soil Mix Recipes for ZZ Plants
Recipe 1
- ¼ part potting mix
- ¼ part perlite
- ¼ part peat moss
- ¼ part vermiculite
This recipe is a well-balanced mix that can provide your ZZ plant with a suitable growing medium. The equal parts of potting mix, perlite, and vermiculite create a well-draining mix that can reduce the likelihood of waterlogged soil.
Peat moss, on the other hand, can retain enough moisture for ZZ plants to have continuous access to water in between waterings. It can also hold nutrients added to the soil during fertilization, consistently supplying your plant with nutrients.
Just make sure to mix them well to fully enjoy each component’s benefits.
Recipe 2
- ¾ part potting soil
- ¼ part succulent soil
This is a perfect mix if you already have succulent soil at home. Since succulent soils typically have perlite and sand, you won’t need to have additional amendments.
However, since succulent soil tends to dry out really quickly, mixing it with a ¾ part potting mix can help slow down the draining process and let the soil retain enough moisture to support the plant’s growth.
Additionally, potting soil typically contains sufficient nutrients to support your ZZ plant’s growth. You can also add a balanced, liquid houseplant fertilizer every 6 to 8 weeks to replenish the soil’s nutrient content.
Signs That ZZ Plant Is in the Wrong Soil
Stagnancy
ZZ plants are known as slow growers, so stagnancy can be easy to miss at times. Typically, they grow two to three stems a year and take about three to five years to reach a mature height of two to four feet.
If you don’t notice any new stem growth during its growing season, then you’re probably using the wrong soil. It can be a sign that your soil doesn’t have enough nutrients or the pH is way out of the recommended range.
When the soil is too acidic or alkaline for the ZZ plant, some nutrients become unavailable, and roots find it difficult to absorb the remaining nutrients in the soil. This means the plant doesn’t get enough resources to support new growth.
Yellowing Leaves
One of the biggest causes of yellowing leaves in most plants, including ZZ plants, is overwatering. This can either be caused by excessive watering or poor soil drainage.
When the soil becomes waterlogged because it can’t drain water properly, it becomes an environment where fungi are likely to grow and cause root rot. Once the roots start rotting, the leaves of your ZZ plant will turn yellow, starting from the lower leaves.
Wilting or Drooping
Wilting or drooping stems are another indication of poor drainage and root suffocation. If the soil retains excess moisture for a long time, the roots will likely drown or suffocate, causing the stems to droop.
Even if the soil has good drainage initially, it can get compacted over time. Compacted soil restricts the roots’ access to oxygen and generally has poor drainage, so it needs to be replaced as soon as possible.
