Everything You Need to Know About Fertilizing ZZ Plants Grown Indoors
ZZ plants are well known as one of the most forgiving indoor plants around and also offer a host of additional benefits. With their tolerance for low light, dry soil, and a range of growing conditions, it’s easy to see why so many love these attractive, low-maintenance plants. But just because ZZ plants are easy to care for doesn’t mean that they don’t have a few basic requirements, including the right fertilizer at the right time. Read on to learn how and when to fertilize your ZZ plants.
Fertilizing ZZ Plants – The Essentials
Fertilize your ZZ plant twice during the growing season (spring and summer), with two months between feedings. Don’t fertilize during the rest of the year. Use a 4-5-4 or 5-5-5 liquid fertilizer diluted to half-strength, or a 10-10-10 fertilizer diluted to quarter strength.
The Role of Fertilizer in Plant Health and Growth
ZZ Plants need several components to grow and thrive: suitable temperature and humidity, light, water, carbon dioxide, and nutrients. When growing outdoors, plants receive what they need from their environment:
- Light from the sun
- CO2 from the air
- Moisture from rain
- Nutrients from decomposing organic matter and minerals in the soil
When grown as houseplants, indoor gardeners must ensure ZZ plants have the correct type of soil mix, light exposure, and water. They also must provide nutrients in the form of fertilizer. But what is in fertilizer, and why are there so many different types?
Most types of fertilizers contain three components: nitrogen, phosphorous, and potassium. Together, these elements are known as primary macronutrients. Each plays a different role in plant health:
- Nitrogen or “N” is essential to foliage growth and plays an important role in photosynthesis. It’s why your ZZ plant’s leaves are dark green.
- Phosphorous or “P” is key to effective photosynthesis and supports flowering and fruiting.
- Potassium or “K” also aids in photosynthesis and helps plants move water and other nutrients throughout their structure.
When you look at the labeling on fertilizer, the amounts of each macronutrient are indicated by the percentage by volume of each in an “NPK” format. An NPK of 10-10-10 means the fertilizer contains 10 percent nitrogen, 10 percent phosphorous and 10 percent potassium. This can also be indicated as a 1:1:1 or balanced ratio. Or, for example, a 24-8-16 NPK would mean 24 percent nitrogen, 8 percent phosphorus and 16 percent potassium, or a 3:1:2 ratio.
Secondary Macronutrients and Micronutrients
Plants also need a smaller amount of elements known as secondary macronutrients. These include sulfur (S), calcium (Ca), and magnesium (M).
Finally, plants also use (much) smaller amounts of so-called micronutrients, like boron (B), chlorine (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), Nickel (Ni), and zinc (Zn).
Plants need different amounts of these macro-and micronutrients to survive. To help your plants thrive, choose a fertilizer that contains the right mix of nutrients. A good quality fertilizer will list the NPK ratio, as well as the amount of secondary macronutrients and other trace micronutrients on the packaging, making it easy to find the right blend.
Types of Fertilizer
Once you’ve figured out the correct ratio for your ZZ plant, consider the different ways fertilizer can deliver those nutrients. Fertilizer comes in two overall categories:
- Organic fertilizers are made from naturally occurring plant, mineral or animal remains. They both last longer in the soil and take longer to improve plant health.
- Synthetic fertilizers are made from chemical compounds. They deliver benefits to plants faster but don’t last as long, so you’ll have to reapply more frequently.
Fertilizer also comes in a range of forms. Water-soluble fertilizers must be dissolved or diluted in water before adding to the soil. Dry fertilizers are granules that are sprinkled on the soil, then break down quickly when moisture is applied. Slow-release fertilizers, which come in the form of spikes or pellets, break down slowly over time and are water-insoluble.
Signs Your ZZ Plant Needs Feeding
ZZ plants are slow growers and tolerate a range of environmental conditions, so you probably won’t be surprised to learn that they don’t require much in the way of fertilization. That said, if your ZZ plant starts to show the following signs, it may be time for a feeding:
- Extremely slow or poor growth
- Thin foliage
- Drooping leaves
However, before treating any of these symptoms by fertilizing, check for other culprits. For instance, overwatering and too much light exposure are more common causes of any ZZ plant issues than under-fertilization. In addition, keep an eye out for common ZZ plant pests and diseases.
When and How Often Should You Fertilize a ZZ Plant?
Fertilize your ZZ plant twice during the growing season, which is spring and summer (this is also the best time for pruning and repotting). Wait two months in between feedings. Don’t fertilize at all during the rest of the year and avoid fertilizing recently propagated ZZ plants.
The Best Fertilizer for ZZ Plants
As a slow grower who doesn’t need extra feeding, choose a balanced 5-5-5 or 4-5-4 liquid fertilizer and dilute it to half-strength. You may also choose a balanced 10-10-10 and dilute even farther, to one-quarter strength. Never apply undiluted fertilizer to your ZZ plant.
Non-water soluble or slow-release fertilizers aren’t recommended for ZZ plants, as it’s harder to control how much the plant receives. Instead, choose a liquid formula and dilute it, with more dilution necessary for more concentrated formulas. Higher NPK numbers require more dilution.
Good choices of store-bought fertilizers include:
You may create your own feed at home, but ZZ plants need so little fertilization that it can be easy to apply too much. The danger lies in over-, not under-fertilizing, so it’s often easier to simply buy an easy-to-measure, pre-made liquid fertilizer, dilute it, and apply it twice during the growing season.
How to Apply Fertilizer
Fertilize your ZZ plant only twice per year, during the spring and summer months. That’s the plant’s growing season. Take a two-month break between feeding.
It’s never a good idea to fertilize a dry plant. The day before you want to fertilize, water your ZZ plant thoroughly. The next day, when the soil is still moist, dilute 4-5-4- or 5-5-5 liquid fertilizer to half strength. Alternately, dilute a balanced 10-10-10 fertilizer to one-quarter strength.
When diluting fertilizer, follow the directions on the container. Just be sure to dilute the fertilizer down to a lower concentration, so it’s not too strong for your plant. ZZ plants aren’t picky about the type of water you use, so tap water is fine.
Slowly pour the diluted fertilizer over the soil in your ZZ plant’s container. Keep pouring until excess flows from the drainage hole. This will help ensure the fertilizer reaches the plant’s roots.
Key Considerations When Fertilizing ZZ Plants
ZZ plants don’t require much feeding, and it’s easy to over-fertilize. If you do apply too much fertilizer, you may notice signs of burn. Yellow spots on foliage, leaf scorch, and root damage are all signs of over-fertilization.
These symptoms may appear quickly after fertilizing or start to appear after a few days or more. If you notice signs of leaf burn, flush water through the soil until it flows through the container’s drainage holes.
Fertilizing ZZ Plants FAQs:
Do ZZ Plants need fertilizer?
ZZ Plants don’t need much fertilizer and should go without for most of the year. Fertilize once or twice, several months apart, only in spring and summer, the plant’s growing period.
When should I fertilize my ZZ Plant?
You should only fertilize your ZZ plant during its growing period, which is during the spring and summer. Wait two months in between feeding, and only fertilize twice per growing season. Do not fertilize in winter.
What is the best fertilizer for ZZ Plants?
You can use a 4-5-4 or 5-5-5 liquid fertilizer diluted to half strength. You may also use a balanced 10-10-10 fertilizer, diluted to one-quarter strength.
Is Miracle Grow good for ZZ Plants?
You can use Miracle Grow on ZZ plants. Just be sure to dilute it first, as you should never use full-strength fertilizer on ZZ plants.
Are used coffee grounds good for ZZ Plants?
ZZ plants don’t need much water. Coffee grounds can increase moisture retention, leading to root rot or mold growth. Don’t use coffee grounds on your ZZ plants.
ZZ plants add a lush tropical look to any room and have the added benefit of requiring little maintenance. That includes fertilization, which only needs to be done twice per year. These easy-care plants only need a bit of feeding, always with diluted fertilizer, during their growing period to grow healthy and strong.
If you’re looking for your next ZZ plant, see our in-depth guide to the best plant shops delivering ZZ plants nationwide.