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NEW Advanced Formula – Boost Flowering & Fruiting – NPK 4-18-38 + Calcium & Magnesium
$39.90 – $387.00
Complete 3-part nutrient system for flowering & fruiting plants
✅ High-phosphorus NPK 4-18-38 for powerful blooms and heavy fruit set.
✅ With Calcium & Magnesium for firmer, tastier, more colourful fruit.
✅ Balanced for hydroponics & soil — steady feeding at every stage.
✅ Boosts yield, flavour & bloom density across all fruiting plants.
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Boost Plant Growth
NPK 4-18-38 + Calcium and Magnesium
A complete, high-performance nutrient system for vegetables, herbs, and leafy greens. This three-part formula provides all essential macro and micronutrients required throughout every stage of plant growth — from seedling to harvest.
Suitable for both hydroponic and soil-based growing.
This Complete Nutrient Set Includes:
- NPK 4-18-38: High phosphorus and potassium to support & promote flowering and fruiting
- Calcium Nitrate: Promotes strong cell structure and calcium uptake
- Magnesium Sulphate: Supports chlorophyll production and nutrient transport
Guaranteed Analysis:
| Nutrient | Percentage (%) |
|---|---|
| Total Nitrogen (N) | 4% |
| Phosphate (P₂O₅) | 18% |
| Potash (K₂O) | 38% |
Each component is designed to work together for healthy, productive plants.
Feeding instructions and mixing ratios are clearly listed on the package.
Fruiting & Flowering Plant Fertiliser – High Phosphorus + Potassium
✅ High-potassium ratio strengthens fruit size, colour, and taste quality.
✅ Includes Calcium & Magnesium for firm fruit, nutrient transport, and plant strength.
✅ Ideal NPK fertiliser for fruit trees & citrus — hydroponic or soil applications.
🇦🇺 Australian-made trusted by growers for consistent, high-yield results.
NPK Ratio
- N 4
- P 18
- K 38
What NPK 4-18-38 Means
Higher P and K to drive budding, flowering and fruit quality while keeping foliage compact.
- Fruiting & flowering: Tomatoes, peppers, berries, cucurbits, roses, citrus.
- Compact growth: Low N helps prevent stretch; pushes blooms & fruit load.
- Already with Cal-Mag: Calcium (19%) strengthens cell walls; Magnesium (9.6%) powers photosynthesis and nutrient movement.
Read More
The 4-18-38 profile prioritises phosphorus and potassium. Phosphorus supports stronger roots and abundant flower initiation, while potassium drives colour, flavour and overall resilience. The modest nitrogen helps prevent stretch, directing energy into blossoms and fruit load. With added Calcium Nitrate and Magnesium Sulphate, plants also receive structural strength, resistance to tip burn, and improved chlorophyll activity.
- Seedling mix and Grow & Bloom recipes included for every stage.
- Gentle on roots; ideal for frequent feeding schedules.
- Works with soil, hydroponics and foliar applications.
Best For These Plants
Perfect for Fruiting Vegetables & Herbs
NPK Fertilizer for Root-to-Bloom Growth
How it Works
Mix all 3 parts
Feed Your Plants
Watch Them Thrive
Reviews From Our Gardener's
Lucas M
Verified Buyer
Sarah L
Verified Buyer
FAQ
You get three essential components that deliver complete nutrition for flowering and fruiting plants:
✔️ NPK 4-18-38 — High phosphorus and potassium for strong flowering, fruit set, and colour.
✔️ Calcium Nitrate — Builds firm fruit, prevents blossom end rot, and supports growth.
✔️ Magnesium Sulphate — Boosts chlorophyll, nutrient uptake, and overall plant health.
Fertilisers with a higher K value in the NPK ratio are considered high in potassium. Examples include NPK 4-18-38, 13-13-36, or 0-0-50, which deliver concentrated potassium to enhance fruiting, colour, and flavour.
At CompleteGrow, our NPK 4-18-38 + Calcium & Magnesium is a professional-grade high-potassium fertiliser designed for fruiting and flowering plants. It improves sweetness, firmness, and resilience across a wide range of crops — including tomatoes, peppers, citrus, and berries.
Which fertiliser is high in both phosphorus and potassium?
High-phosphorus and high-potassium fertilisers like NPK 4-18-38 combine the two most important bloom nutrients — phosphorus (P) for root and flower formation, and potassium (K) for fruit size, quality, and colour.
This balanced blend provides full bloom support, making it ideal for plants that need energy for flowering and fruit set, such as tomatoes, strawberries, capsicums, and citrus trees.
What is the best high-potassium fertiliser in Australia?
For Australian growers, CompleteGrow NPK 4-18-38 + Calcium & Magnesium is one of the best high-potassium fertilisers available. It’s crafted for consistent results in hydroponic and soil-based systems, ensuring improved fruit yield, colour development, and disease resistance across all major crops.
High-phosphorus fertilisers have a larger middle number in their NPK ratio — such as NPK 4-18-38, 10-52-10, or 10-30-20.
These blends encourage root growth, early flowering, and strong bud formation, making them ideal for fruiting and flowering plants.
For Australian growers, CompleteGrow NPK 4-18-38 + Calcium & Magnesium is a professional-grade fertiliser high in phosphorus and potassium, delivering powerful bloom and fruit performance.
Fruit trees require a fertiliser rich in phosphorus (P) and potassium (K) to support flowering, fruit set, and sweetness.
A formula such as NPK 4-18-38 provides the ideal nutrient balance for strong root systems and heavy fruit production, while helping prevent leaf drop and poor fruit colour.
When enhanced with Calcium & Magnesium, this blend offers professional-grade performance for citrus, mango, avocado, and stone-fruit trees — suitable for both hydroponic and soil-based growing systems.
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