Snow and Sugar Snap Peas

Start from seed: March-May, August-September

Optimum soil temperature for germination: 10-24°C

Plant seedlings: April-May, September

Plant spacing: 5-10 cm

Days to maturity: 55-90 days

Introduction

Snow peas (Pisum sativum var. macrocarpum), are also called mange-tout which means “eat all” in French, belong to the Fabaceae family. Unlike traditional garden peas, snow peas have edible flat pods that are harvested before the seeds inside fully develop. Sugar snap peas have expanded seeds inside an edible rounded pod. All types of peas are planted in the same way.

Snow peas have been cultivated for centuries, originating in the Mediterranean region and Central Asia. They were first introduced to Europe in the 16th century and later spread worldwide due to their versatility in cooking and nutritional benefits. They are particularly popular in Asian cuisine, especially stir-fries, and can be enjoyed both raw and cooked.

The plants produce delicate white, pink or purple flowers, depending on the variety. Snow peas grow best at temperatures between 15 and 20⁰ C making them well-suited to Canberra’s climate when planted at the appropriate time.

Site and soil

Snow peas grow best in full sun, requiring at least 6 hours of sunlight daily for optimal growth. Plants can can tolerate light frost once established, but flowers and developing pods may be damaged by heavy frost and temperatures above 30⁰ C.

They prefer well-draining soil that’s rich in organic matter with a pH between 5.8 and 6.8. Before planting, prepare the soil by incorporating compost or well-rotted manure and complete organic fertiliser 2-3 weeks prior to planting to improve fertility and structure.

Snow peas, like all legumes, can convert nitrogen from the air into forms of nitrogen used by plants. This is achieved through nodules on their roots that house nitrogen fixing bacteria, therefore they do not require nitrogen-rich soil. They perform well following heavy-feeding crops in your rotation plan.

If growing in pots, use a good quality potting mix enriched with compost. Choose containers at least 20-30 cm deep and wide to accommodate their root system.

For details on preparing the soil and pots, including the use of lime, dolomite, gypsum and fertilizers please refer to the COGS guide to garden bed preparation.

Planting Seeds and Seedlings

In Canberra, snow peas can be sown in two windows. Keep in mind that they grow best between 15-20⁰ C in the day and 7-18⁰C at night. Planting from March to May allows seed to germinate before it gets really cold. Plants will grow slowly then take off in spring and flower, producing pods in spring and early summer before the heat prevents further flowering. Alternatively, plant seeds in August or early September so that they grow quickly and produce before the heat of summer. The optimum soil temperature for germination is 10-24°C.

Sow seeds directly into the garden bed approximately 2-3 cm deep, spaced 5-10 cm apart in rows far enough apart to allow harvesting from both sides of the trellis or supporting structure. Dwarf varieties may need more space between rows as they have a broader growth habit than climbing varieties.

To prevent seed rot, plant into moist soil and avoid watering until germination occurs, which usually takes 7-10 days. Some people find that soaking seed for 24hours prior to planting speeds up germination. In cold weather, germination may be slower. 

Snow peas can be raised as seedlings for transplanting later. However, they prefer direct sowing as they don’t always transplant well due to their delicate root systems. It is far more cost effective to sow pea seed than to purchase seedlings. If starting in pots, sow 2-3 seeds per pot and thin to the strongest seedling once they have their first true leaves. Seedlings can be transplanted when they have 4-5 sets of leaves.

Set up supports for climbing varieties at planting time to avoid disturbing the roots later. For climbing varieties, supports should be 1.5-2 meters tall.

After planting, a light application of seaweed solution will help prevent transplant shock and stimulate growth.

Cultivation

Snow peas are a cool-season crop growing well when day time temperatures are below 30⁰ C Once established, mature plants can tolerate light frosts, though heavy frosts may kill plants, damage flowers and prevent pod formation.

Climbing varieties need sturdy support structures at least 2 meters tall. Traditional options include bamboo teepees, trellises, or netting attached to a sturdy frame. Gridded galvanised sheep panel mesh attached to star pickets works well and will last for many years. Install supports prior to planting to avoid disturbing roots later. Plants may need their tendrils directed towards the supporting structure. Once attached the plants will climb easily. Dwarf varieties generally don’t need support but may benefit from light staking in exposed areas to prevent wind damage. Some gardeners use low brush fencing or twiggy branches to provide light support for dwarf varieties.

Regular watering is essential, particularly during flowering and pod development. Aim to keep the soil consistently moist but not waterlogged. Newly planted seedlings may need watering once or twice a day during warm weather. Insert your finger into the soil to check moisture levels – soil should feel cool and moist, if it feels dry, the plants need water.

A monthly foliar spray with seaweed solution; a mix of worm juice, seaweed and compost tea; or trace elements will help boost growth and resilience to pests and diseases.

Mulching with organic materials like straw, lucerne hay, or sugar cane mulch helps retain soil moisture, feeds soil microbes, suppress weeds, and keep roots cool during warmer weather.

Weed regularly, especially when plants are young, as weeds compete for nutrients, water, and light.

Harvesting

Snow peas should be harvested when pods are flat and tender, typically around 55-90 days after planting, depending on growing conditions and variety. The pods should be picked before the peas inside begin to swell significantly.

For the best flavour and texture, harvest in the morning and when pods are young – about 7-8 cm long for most varieties. Regular harvesting (every 2-3 days) encourages the plant to keep producing flowers and pods, extending the harvest period.

To harvest, hold the vine with one hand and gently snap or cut the pod from the plant with the other hand. Using scissors or garden snips can help avoid damaging the plant.

Snow pea shoots and flowers are also edible and make excellent garnishes and additions to salads.

After the final harvest, cut the plants off at ground level rather than pulling them out. This allows the nitrogen fixing nodules to break down in the soil, releasing nutrients for the next crop.

Problems

The best approach is to have a reliable Australian reference book to identify problems. Garden Pests, Disease and Good Bugs by Denis Crawford is recommended.

A general strategy to follow with any problem is to observe the plant carefully before taking action. Identify the problem then carefully consider the course of action. For example, with pest insects, you often can see a predator nearby. If you watch and wait the predator may deal with the problem for you. Beneficial predatory insects which feed on pest insects can be purchased from suppliers such as Bugs for Bugs. If the problem needs further action the above recommended book has suggestions.

Practicing good garden hygiene, crop rotation, and maintaining plant vigour by providing adequate nutrients are key strategies for prevention.

Several pests and diseases can affect snow peas grown in Canberra’s cool temperate climate:

• Slugs and snails can be particularly problematic for young seedlings. Use physical barriers like eggshells, coffee grounds, or commercially available slug and snail baits (iron EDTA). Checking plants and surrounding habitat in the evening or early morning to collect slugs and snails is a good idea.
• Birds and mice may eat seeds before germination. Protect newly sown seeds with netting or plant extra to compensate for losses.
• Aphids These small sap-sucking insects can cluster on the undersides of leaves, causing distortion and stunting. Control with insecticidal soap, neem oil, pyrethrin or by encouraging beneficial predators like ladybugs and lacewings. Look for aphid mummies which are evidence that the aphid has been parasitised. Eggs can also be parasitised and will appear bronze in colour. Generally speaking, plants that are high in soluble nitrogen (nitrates and ammonia) are prone to attack by sap sucking insects. Ideally avoid using soluble nitrogen fertilisers and ensure plants have adequate trace elements. This can be achieved by using foliar sprays.
• Powdery mildew is the most common disease affecting snow peas, appearing as a white powder on leaves and stems, particularly in warm, humid conditions or when plants are stressed. Good air circulation, avoiding overhead watering, and a spray made from 1 part milk to 9 parts water can help control mild cases. For prevention, choose varieties with resistance to powdery mildew.
• Root rot can occur in poorly drained soils, causing yellowing and wilting of plants. Ensure good drainage and practice crop rotation to avoid this issue.

Practice a 3–4-year rotation for all legumes to prevent the buildup of soil-borne diseases. Avoid planting snow peas after other peas or beans to reduce the risk of pest and disease transfer.

Recommended Varieties

Local nurseries, farmers markets, and specialized seed suppliers are good sources for obtaining varieties suited to Canberra’s growing conditions. Several snow pea varieties perform well in Canberra’s climate:

• Oregon Giant: A popular commercial variety reaching 1-1.3 meters tall with large, flat pods up to 14 cm long. Shows some resistance to powdery mildew.
• Oregon (bush): A more compact variety growing to about 70 cm, good for small gardens or growing in pots.
• Mammoth Melting: A tall variety (up to 2 meters) that produces large, sweet pods and is a heavy cropper.
• Yakumo: Features attractive purple flowers and large, flat pods. Plants can grow 2-2.5 meters tall.
• Golden Sweet: Produces unusual yellow pods and can grow to 2 meters tall. Best picked young before pods develop bitterness.
• Dwarf Grey Sugar: A smaller variety that doesn’t require as much support, making it suitable for containers or small spaces.

References

1. ActiveVista. Oregon Giant Snow Pea Seed [Internet]. 2024. Available from: https://www.activevista.com.au/product/oregon-giant-snow-pea/
2. Bubel, Nancy. The New Seed-Starters Handbook. Rodale Books, 2018.
3. Crawford D. Garden Pests, Disease and Good Bugs. Australia: ABC Books; 2015.
4. Dove, Helena. Botany of the Kitchen Garden, Kew Publishing, Royal Botanic Gardens Kew, UK, 2023. 
5. Fanton, Michel and Jude. The Seed Savers Handbook. The Seed Savers Network, Australia, 1993.
6. Johnny’s Selected Seeds. Growing Peas: Planting, Spacing, Care & Diseases [Internet]. 2025 [cited 2025 May 6]. Available from: https://www.johnnyseeds.com/growers-library/vegetables/peas/peas-key-growing-information.html