Cucumber Fertiliser Guide: Best NPK Ratio, Soil Prep & Growth Tips

Want crisp, juicy cucumbers packed with flavour? It all starts with the right fertiliser and NPK balance. Whether you’re growing cucumbers in garden beds, pots, or a hydroponic system, feeding them correctly is essential for rapid growth, flowering, and fruit development. Cucumbers are fast-growing, nutrient-hungry plants that reward proper care with large harvests. In this guide, you’ll learn everything you need to know to grow productive cucumber plants in Australia, including:

• The best fertiliser for cucumbers at each growth stage
• What NPK ratio to use and when
• How to prepare soil for cucumber success
• Signs of nutrient deficiencies in cucumbers

Cucumber plants are heavy feeders because of their rapid growth and high water content. Without a steady supply of essential nutrients, they quickly show signs of stress—small fruit, yellowing leaves, or poor flowering. That’s why applying the right fertiliser at the right time makes all the difference between a poor yield and a bumper crop. Let’s dive in and explore how to give your cucumbers the nutrition they need—whether you’re growing slicing types, pickling varieties, or burpless hybrids.

Popular Cucumber Varieties Grown in Australia

Australia is home to several cucumber varieties, each with unique growth habits, shapes, and flavour profiles. Whether you’re buying from Woolworths or growing them at home, it’s important to understand the differences to choose the right fertiliser and care routine for each type.

Lebanese Cucumbers

One of the most widely consumed varieties in Australia, Lebanese cucumbers are small, thin-skinned, and mild in flavour. They’re popular in supermarkets like Woolworths for their crunchy texture and versatility in salads and wraps.

• Size: 10–15 cm long
• Skin: Smooth, dark green, and nearly seedless
• Growth habit: Compact vines, ideal for small spaces and pots
• Feeding tips: Respond well to balanced NPK early on, followed by a high-potassium booster during flowering

Continental Cucumbers

Also called telegraph cucumbers, these are the long, smooth-skinned types commonly wrapped in plastic at grocery stores. They grow on vigorous vines and require trellising for best shape and airflow.

• Size: 25–35 cm long
• Skin: Glossy, thin, and dark green
• Growth habit: Climbing or sprawling vines that benefit from vertical training
• Feeding tips: Heavy feeders — need consistent fertiliser throughout the season, especially phosphorus and potassium

Pickling Cucumbers (Gherkins)

These smaller, blocky cucumbers are grown primarily for pickling, but they can also be eaten fresh. They mature quickly and are suited to smaller gardens or container growing.

• Size: 8–12 cm, short and stubby
• Skin: Bumpy and thicker than other varieties
• Growth habit: Compact bush types or smaller vines
• Feeding tips: Benefit from fast-acting fertilisers — high phosphorus during flowering and potassium during fruit swelling

Burpless Cucumbers

These hybrid varieties are bred to have fewer bitter compounds and a thinner skin, making them easier to digest. They’re gaining popularity in home gardens and farmers markets.

• Size: Varies by cultivar, usually 20–30 cm
• Skin: Smooth and tender, often lighter green
• Growth habit: Fast-growing vines that benefit from trellising
• Feeding tips: Requires regular fertiliser, especially during flowering and fruit set

Growing Tip:

Regardless of the type, all cucumbers benefit from consistent moisture, mulching, and a feeding schedule that shifts from nitrogen-focused early growth to potassium-heavy fruiting support. Tailoring your approach slightly by variety helps maximise yields and improve fruit quality.

If you’re unsure which variety to grow, Lebanese cucumbers are a great choice for beginners due to their short growth cycle, manageable size, and reliability in both pots and garden beds. They’re also the most likely to match what you’ll find fresh at Woolworths or Coles.