Zamioculcas zamiifolias, better known as ZZ plants, are popular for being tough as nails – they can tolerate both low light conditions and periods of drought better than most houseplants. These hardy plants are also not fussy when it comes to the type of soil they grow in – in most cases, any potting soil mixed with perlite and coarse sand should suffice.
That said, most growers would like their ZZ plants to reach their full growing potential. We all love seeing our plants flourish, and to achieve this, you need an appropriate medium to boost your plant’s growth.
So, let us go over the must-have features you should consider when choosing the best soil for your ZZ plant.
Factors to consider when choosing soil
For proper growth, ZZ plants need nutrition from the soil. Unlike in their natural habitat, houseplants like ZZs are restricted to small containers, so you need to carefully select an appropriate potting mix that includes balanced nutrients for their health and survival.
In general, ZZ plants prefer a nutrient-dense, porous potting soil mix – aeration is important to allow the roots to breathe. Any regular potting mix should be sufficient for a ZZ plant to stay healthy, but if you want your plants to really flourish, there are a number of soil mixes you can choose from to give your plant that extra boost.
But first, you should understand the important factors at play when it comes to choosing a potting mix for ZZ plants. These are as follows:
1. Nutrient-rich soil
Plants get their nutrients from the soil, and the main nutrients needed to foster growth are nitrogen (N), phosphorus (P), and potassium (K). These macro-nutrients are commonly known as NPK. Other micronutrients that ZZ plants need to maintain their vigor are copper, zinc, iron, manganese, boron, molybdenum, and nickel.
Plants, in their natural environment, get these nutrients from the decomposed organic matter in the soil. However, growing them away from their habitat limits their access to these nutrients, so if you want your ZZ plant to thrive, you should consider a medium that contains the same essential nutrients found in its natural habitat. For this reason, growing ZZ plants indoors requires the addition of fertilizer – be it organic or synthetic.
2. Well-draining soil
ZZ plants cannot tolerate compacted or clay-like soil, because it drains poorly. Like most plants, their roots are delicate and prone to rotting when left to sit in soggy, wet soil for extended periods.
Roots naturally breathe oxygen through tiny pores. Oxygen is essential for a plant’s cellular respiration. In other words, just like humans and animals, plants depend on oxygen for survival.
For this reason, the soil must be well-draining to allow the roots to breathe. If the soil is too dense or compact, it will hold excess water around the roots, eventually drowning them. An oxygen-deprived plant will also become vulnerable to root rot and fungal diseases.
3. Good aeration
Aeration reduces soil compaction and allows more oxygen to reach the roots. Hence, aerated soil is another essential for your ZZ plant’s vigorous growth. Do keep in mind, though, that the soil must also hold enough moisture and nutrients to meet the plant’s needs.
What is the best soil mix for ZZ plants?
Fortunately, ZZ plants are not picky when it comes to their growing medium. However, we want our houseplants to grow beautifully and not just survive! Choosing the ideal soil mix, combined with proper care, will ensure that our ZZ plants flourish and grow happily for many years to come.
Here are some tips for choosing the best soil mix for your ZZ plant:
1. Choose a good-quality mix
First off, you need to consider a good quality soil mix that has the basic requirements – good aeration, well-draining, and nutrient-rich. Once you have found the perfect growing medium, stick with it as your plant grows. Be sure to replace the soil as needed, especially when transferring your plant to a new pot.
The following ingredients help create good drainage and aeration in your soil mix, while still holding enough nutrients and moisture for your ZZ plant to flourish:
- Light, well-aerated potting soil
- Coarse horticultural sand
- Pine bark fines
- Sphagnum peat moss
- Coco coir
You can follow this recipe to create the best-quality soil for your plant:
- Two parts all-purpose potting soil
- One part perlite, pink bark fines, or coco coir
- One part horticultural sand
2. Soil and cactus mix
Novice growers might wonder whether it is okay to use a cactus mix for their ZZ plants. The good news is that cactus and succulent mixes actually work well for ZZs and other houseplants. Cactus mix has good aeration and drainage qualities; it is made with limestone, sand, and perlite, making it porous yet moisture and nutrient absorbent.
If you want to use cactus mix for your ZZ plant, here is the recommended recipe:
- Three parts potting soil, such as Miracle Grow
- One part cactus mix
- About a handful of organic material or compost
3. Soil and perlite mix
Perlite is a naturally-occurring siliceous rock with an extremely porous structure. When added to the soil mix, it helps improve the drainage capacity and aeration of the growing medium. Perlite also makes the soil light, yet provides good retention of moisture and nutrients. That is why gardeners find perlite mix a balanced medium that works well for most houseplants.
To create a good perlite mix, follow this recipe:
- One part all-purpose potting soil
- Two parts perlite
- One part sphagnum peat moss
4. Pre-made soil blends
Of course, if you do not want the hassle of making your own soil mix, you can always go for pre-made products. These options offer the most convenience, being ready to use as needed. Some of the best pre-made soil mixes for ZZ plants are FoxFarm Ocean Forest Potting Soil and Espoma Organic Cactus Mix.
Do ZZ plants need cactus soil?
If you are looking for fast-draining soil, you might find cactus soil a great option. The only drawback of using this as your growing medium is that you risk the soil drying out a bit faster than your ZZ likes. Dehydration in ZZ plants causes leaf browning and drooping, both of which are undesirable and unhealthy traits.
To take advantage of its excellent drainage capability without dehydrating your plant, it is recommended to mix the cactus soil with a high-quality potting soil. This way, you can minimize the risk of root rot while ensuring that your ZZ plant receives enough moisture and nutrition.
Do ZZ plants grow well in acidic soil?
ZZ plants prefer a soil with pH range between 6.0 and 7.0, meaning they do better in a slightly acidic environment. However, too much acidity in the soil can be toxic and cause issues with nutrient uptake. As a result, your plant will struggle with slow growth and leaf burn similar to that caused by overfertilization.
When to repot your ZZ plant
While repotting can cause shock in your ZZ plant, this process is sometimes necessary for several reasons. You need to transfer your plant to a new pot and soil if you notice any of these signs:
- Roots starting to grow out of the pot’s drainage holes
- Browning and wilting leaves
- Stunted growth
- Pot starting to break due to expansion of the roots
Remember that you should only repot your ZZ plant during spring and summer. Avoid repotting it during its dormant season, as this can cause irreversible damage to the root system.
To maintain your plant’s vigor, consider repotting it every two to three years.
Choosing the right pots for a ZZ plant
ZZ plants are popular for being low-maintenance and forgiving, so any pot with good drainage should work fine. Some common pot materials include terracotta, clay, concrete, plastic, fiber, metal, and even coir.
While porous pots like terracotta and coir can easily wick moisture from the soil, materials like plastic will retain more moisture inside the pot. Keep this in mind when choosing a pot that best suits your requirements.
Also remember that ZZ plants do not like to be root-bound, so choose a pot that is slightly larger than your plant – the pot wall should be approximately an inch away from the root ball. When the roots have grown significantly larger, you can repot your plant into the next pot size, about two inches larger than the previous one. However, do not choose a pot or container that is overly large, as the extra space inside it will retain extra water, thus increasing the plant’s risk of root rot and fungal issues.
Knowing the right soil conditions for your ZZ plant will encourage faster and healthier growth of its foliage, as well as making your plant less vulnerable to certain pests and plant diseases. With the right care and soil recipe, you can easily keep your ZZ looking its best for years to come!
Image: istockphoto.com / Bilal photos