Monstera Fertiliser & Plant Care Guide: NPK, Feeding Schedule & Soil Tips

Monstera, also known as the Swiss cheese plant, is one of Australia’s most beloved indoor plants—and with the right fertiliser, it can thrive into a lush, tropical statement piece. From its iconic split leaves to its vining growth habit, Monstera deliciosa requires more than just light and water. Feeding it correctly with a balanced NPK fertiliser supports vibrant foliage, larger leaf development, and strong root systems.

This in-depth guide will walk you through how to properly fertilise and care for your Monstera in Australian indoor environments. We’ll cover:

How to choose the right NPK ratio for Monstera growth
Feeding schedules tailored for indoor conditions
Signs your Monstera needs nutrients
Soil mix and pH preferences for healthy roots

Unlike outdoor garden plants, Monsteras grow in confined containers, meaning their access to nutrients is limited. Over time, even premium indoor potting mixes become depleted, and growth slows. By understanding Monstera’s fertilising needs, you can unlock faster growth, fuller foliage, and stronger aerial roots—without overfeeding or burning delicate roots.

Let’s get started with the core of Monstera health: the nutrients that power its jungle-like growth indoors.

Fertilising Monstera: Best NPK Ratio and Feeding Schedule

Monsteras are considered moderate to heavy feeders during their active growing season, which typically runs from early spring to mid-autumn in Australia. The most effective fertiliser plans adapt to the plant’s growth phases and indoor light availability.

What NPK Ratio Does Monstera Need?

The best NPK fertiliser for Monstera is a **balanced or foliage-focused formula**, such as 20-20-20. These deliver steady nitrogen for leaf growth, a touch of phosphorus for root support, and adequate potassium to strengthen stems and resistance to stress.

N (Nitrogen): Encourages leaf size, colour and fenestration (those iconic holes)
P (Phosphorus): Helps build strong roots and supports indoor plant resilience
K (Potassium): Improves drought tolerance, cell strength, and growth consistency

Our recommended product for general Monstera health is CompleteGrow 20-20-20 Liquid Fertiliser, which can be applied monthly during the growing season.

Feeding Schedule

Spring to Autumn: Fertilise every 3–4 weeks with diluted liquid feed
Winter: Pause or feed lightly once every 6–8 weeks if growth continues

Always water your Monstera lightly before applying fertiliser to avoid root burn. Liquid feeds work best because they distribute nutrients evenly throughout the root zone and are absorbed quickly—especially in indoor settings with less microbial activity.

Avoiding Overfeeding

Monsteras are sensitive to salt buildup from overfertilising. If you’re seeing brown leaf edges, slowed growth, or white crust on soil, it may be a sign of excess nutrients. Always flush the pot with clean water every 6–8 weeks to remove any fertiliser residue.

Micronutrients for Monstera

Trace elements like magnesium, iron, and manganese are critical for healthy leaf colour and new growth. CompleteGrow’s liquid blends include a full spectrum of these, but yellowing leaves or chlorosis may still develop under low light. Foliar feeding can help restore vibrancy when used sparingly.

In short, feeding your Monstera consistently—but carefully—supports its signature jungle look. A balanced NPK and regular schedule result in more splits, larger leaves, and a healthier overall plant indoors or on shaded patios.

Monstera Varieties Grown in Australia & Their Fertiliser Needs

While most people think of the large, split-leaf Monstera when they hear the name, there are actually several species and cultivars grown across Australia—each with its own size, leaf shape, and fertiliser requirements. Whether you’re buying from local nurseries, major retailers like Bunnings, or boutique plant shops, it’s helpful to understand which variety you have to tailor your care routine accordingly.

Monstera deliciosa

This is the classic and most widely grown Monstera in Australia. Known for its large, perforated leaves and vining growth habit, Monstera deliciosa is ideal for indoor pots, large planters, or trained up a moss pole.

Size: Can reach over 2 metres indoors with support
Leaf type: Deeply lobed with large natural splits and holes (fenestrations)
Fertiliser needs: High nitrogen in spring and summer to support leaf production; benefit from a balanced 20-20-20 every 3–4 weeks

As this plant matures, its feeding requirements increase. Large, older Monsteras tend to grow more quickly and use nutrients faster, especially in bright rooms. Ensure consistent watering and flush the soil every few months to prevent salt buildup from liquid fertilisers.

Monstera adansonii

Commonly referred to as the “Swiss cheese vine,” Monstera adansonii is a smaller, more delicate species often grown in hanging baskets or on trellises. Its leaves are smaller than deliciosa but packed with holes, making it highly decorative.

Size: Vines up to 1–1.5 metres indoors
Leaf type: Elongated, oval-shaped with many fenestrations
Fertiliser needs: Moderate feeders; thrive with diluted fertiliser every 4–6 weeks; avoid overfeeding

Adansonii tends to grow quickly under bright, indirect light. Because it has thinner stems and more delicate leaves, avoid high-strength fertilisers. Instead, dilute a balanced liquid feed like CompleteGrow 20-20-20 to half-strength.

Monstera ‘Thai Constellation’

A premium, variegated cultivar of deliciosa, the Thai Constellation features cream-to-white marbled patches across its leaves. It’s slower-growing and more sensitive to overfeeding than green varieties.

Size: Similar to deliciosa but slower-growing
Leaf type: Large, split leaves with star-like white variegation
Fertiliser needs: Feed sparingly—every 4–6 weeks; use a low-nitrogen fertiliser to preserve variegation

Too much nitrogen can cause Thai Constellations to revert to green. Use a fertiliser with a lower N value, such as 10-10-20 or apply CompleteGrow 20-20-20 at 25–50% dilution. Always ensure excellent drainage and avoid soggy soil, which this variety is especially prone to reacting badly to.

Monstera siltepecana

A rarer vining species with silver-patterned juvenile leaves that change form as the plant matures. This variety is gaining popularity among collectors and indoor plant enthusiasts across Australia.

Size: Smaller vines suited to terrariums, baskets, or climbing setups
Leaf type: Lance-shaped with metallic silver markings
Fertiliser needs: Light feeders—once every 6 weeks during active growth

Siltepecana prefers high humidity and drier soil conditions between watering. Fertilise only when actively growing and ensure good airflow around the roots.

Choosing the Right Fertiliser by Variety

While all Monstera species benefit from complete NPK fertilisers, their feeding frequency and strength should match their growth rate. Fast-growing types like deliciosa need more frequent feeding, while rarer or variegated varieties benefit from a gentler approach.

If in doubt, start with a diluted dose of CompleteGrow 20-20-20 every 4 weeks during spring and summer. Monitor leaf colour and size to guide future feeding levels.

Knowing your Monstera’s variety not only helps with fertiliser decisions—it also helps you pick the right pot size, light level, and watering routine. Whether you’re caring for a classic deliciosa or a prized Thai Constellation, the right nutrition plan ensures bold, beautiful growth year-round.

Soil Mix, Drainage & Signs Your Monstera Needs Fertiliser

Fertiliser alone won’t create a thriving Monstera—your soil mix, watering practices, and drainage setup are just as important. Monsteras prefer loose, well-draining, nutrient-retentive soil that mimics the tropical forest floor.

Ideal Soil Mix for Indoor Monstera

Base: High-quality indoor potting mix (peat-free if possible)
Drainage: Add 20–30% perlite or pumice to improve airflow
Organic content: Mix in coconut coir or aged bark for structure
pH level: 5.5 to 6.5 for optimal nutrient uptake

Do not use garden soil or heavy composts indoors. These can compact, cause water retention, and suffocate the roots. Monsteras need oxygen around their roots to support those thick aerial root structures and broad leaves.

Signs Your Monstera Needs Fertiliser

Slow or no new leaf growth during spring/summer
Smaller leaves without splits or holes (fenestrations)
Pale or yellowing leaves even with adequate water
Weak or drooping stems despite correct light and humidity

These symptoms often indicate nutrient deficiency—especially nitrogen or magnesium. If your Monstera has stopped producing large, fenestrated leaves, it’s usually a sign that it needs consistent feeding with a balanced NPK and trace elements.

General Monstera Care Tips

Lighting: Bright, indirect light is best. Avoid full sun, which burns leaves.
Watering: Let the top 5–7 cm of soil dry before watering. Never keep it soggy.
Pot selection: Use breathable pots with drainage holes to avoid root rot.
Humidity: Keep at 50% or higher. Mist leaves or use a pebble tray for dry homes.

Re-pot every 1–2 years to refresh soil and give roots more space. During each repot, apply a root-stimulating fertiliser to help the plant adjust and recover.

Healthy Monsteras respond quickly to care improvements—new leaves emerge fast and grow larger when given the right feeding and light. Combined with CompleteGrow fertilisers, your Monstera will reward you with dramatic foliage that transforms any room or covered patio.