Sweet peas (Lathyrus odoratus) are a favorite among gardeners worldwide, known for their fragrant, delicate flowers and long-lasting cut blooms. Whether you're growing them for their beauty, scent, colour or to add height and charm to your garden, getting the best results starts with strong seedlings and proper care.
In this guide, we’ll cover:
✅ When and where to plant sweet peas
✅ Preparing soil and planting seedlings
✅ Best fertilising practices
✅ Staking and support for longer stems
✅ Watering, pruning & pest management
If you want even longer, stronger stems, we’ll also share insights from Gerard Oldfield, 16-time Most Successful Exhibitor of the Sydney Royal Easter Show, owner of Highland Dahlias, who swears by a simple but effective trick!
When to Plant Sweet Pea Seedlings
Sweet peas thrive in cooler temperatures, so the best time to plant them depends on your climate:
- Temperate Climates (Mild Winters, Cool Springs) → Plant in Late Winter to Early Spring
- Cool & Mediterranean Climates (Mild to Cold Winters) → Plant in Late Autumn to Winter
- Warmer Climates like Australia (Short Winters, Hot Summers) → Plant in Late Autumn for Best Results
- Cold Climates (Harsh Winters, Frost Risk) → Start Indoors in Late Winter & Transplant in Spring
For most regions, autumn to early spring is the ideal time, giving sweet peas enough time to establish before warm weather arrives.
Where to Plant for Best Growth
Sweet peas need full sun (at least 6 hours a day) and well-draining soil. They grow well in:
- Garden beds with a trellis or fence for climbing varieties
- Large containers with bamboo stakes or netting
- Raised beds for better drainage
Avoid planting in areas with strong afternoon sun in hotter regions, as excessive heat can shorten their flowering period.
How to Prepare the Soil & Plant Seedlings
- Improve Soil Structure – Sweet peas prefer rich, well-draining soil with plenty of organic matter. Add compost or aged manure before planting.
- Boost Soil Health with Products Like Humus Powder – Incorporating a product like Super-Charged Humus Powder into the soil enhances microbial activity and improves nutrient retention, setting the stage for healthier, more resilient plants.
- Planting Seedlings – Space seedlings 15-20cm (6-8 inches) apart and plant at the same depth as in their nursery pots. Water them in well after planting.
Fertilising for Stronger Stems & More Blooms
Sweet peas are heavy feeders, meaning they require consistent nutrition to develop long, strong stems and abundant flowers. A balanced fertiliser with essential nutrients is key to achieving vibrant blooms and sturdy growth.
What Makes a Good Fertiliser for Sweet Peas?
- Low to Moderate Nitrogen (N) – Too much nitrogen promotes leafy growth at the expense of flowers.
- High Phosphorus (P) & Potassium (K) – Encourages strong roots, sturdy stems, and prolific blooming.
- Micronutrient-Rich – Elements like magnesium, iron, and boron support healthy flower formation.
Why Choose UGF6in1 for Sweet Peas?
✔️ Balanced Nutrition – UGF6in1 contains a 9-2-6 NPK ratio, delivering the right nutrients to promote strong, healthy growth without excessive foliage.
✔️ Organic-Based & Gentle – Sweet peas can be sensitive to synthetic fertilisers, making UGF an excellent natural alternative.
✔️ Packed with Micronutrients & Biostimulants – Supports plant resilience, improves flowering, and enhances soil microbiology.
When & How to Apply UGF6in1 for Best Results
- Before Planting: Apply UGF6in1 as a soil drench (1:100 dilution) to boost root development and establish strong seedlings.
- Early Growth Stage: Continue soil drenching every 2-3 weeks to build plant strength and support stem elongation.
- Bud Formation & Flowering: Switch to foliar feeding every 7-10 days (1:200 dilution) to maximize nutrient uptake and enhance flower size, colour, and longevity.
💡 Gerard Oldfield’s Expert Tip for Longer Stems:
Renowned grower Gerard Oldfield recommends regular foliar feeding with UGF6in1 to maintain strong stems and healthy leaves throughout the flowering season. This reduces yellowing, improves bloom quality and extends vase life for cut flowers.
👉 While the video below shows Gerard’s results with flower stocks, the same foliar feeding method is part of his routine with sweet peas and other cut flowers too. Here are a few images of Gerard’s sweet peas grown using UGF 6-in-1:
Providing Support for Climbing Sweet Peas
Climbing sweet peas need support to reach their full potential. Options include:
- Trellises & Netting – Ideal for garden beds and raised beds.
- Bamboo Stakes & Strings – Great for small spaces and pots.
- Chicken Wire Fencing – Allows tendrils to attach naturally.
TIP: Tie young vines loosely to their support to encourage upward growth.
Watering, Pruning & Deadheading for More Blooms
✔️ Water deeply 2-3 times a week, ensuring soil is moist but not soggy.
✔️ Pinch out the growing tips once plants reach 15cm (6 inches) tall to promote bushier growth.
✔️ Deadhead regularly – Removing spent flowers encourages more blooms.
Pest & Disease Management
🐛 Aphids & Thrips – Use insecticidal soap or neem oil if infestations occur.
🍂 Powdery Mildew – Foliar feeding with UGF 6-in-1 can help strengthen plant resilience.
🚫 Snails & Slugs – Use organic deterrents like crushed eggshells or beer traps.
Final Thoughts
Sweet peas are one of the most rewarding flowers to grow. By starting with strong seedlings, providing the right support, feeding regularly with a fertiliser like UGF6in1 and following proper care techniques, you can enjoy a season full of vibrant, long-stemmed blooms!
🌸 Ready to grow your best sweet peas yet?
Try UGF6in1 and see the difference for yourself!
💡 We’re always updating our guides to stay helpful and relevant. Have a tip, research update, or something we missed? Let us know — we’re all ears!
💡 Got an idea, special insight, or story worth sharing? We're open to quality blog contribution ideas that can help our community grow. If you'd like to contribute, get in touch — we'd love to hear from you. 😊
