Peas – Growing Guide

Overview

• Name: Peas
• Botanical Name: Pisum sativum
• Plant Family: Fabaceae
• Native to: Western Asia and North Africa

Description

Peas are annual herbaceous legumes cultivated for their edible seeds and pods. As annuals, they complete their life cycle within one growing season. Pea plants can have either a bushy or climbing growth habit, typically reaching heights of 30-200 cm (1-6 ft), depending on the variety. Taller varieties have slender, vining stems that use branched tendrils to climb, and therefore, need supports. The plants have compound leaves with one to three pairs of oval leaflets, each 1-6 cm long.

The pea flowers are usually white or pink and form along the vine. They primarily self-pollinate, a process where pollination occurs within the same flower that contains both male and female parts, typically before the flower opens—a phenomenon known as cleistogamy. The pollinated flowers develop into green pods that can be straight or curved, containing 2 to 10 peas per pod. Peas are harvested before they fully mature for the best sweetness.

Interesting Facts

• Peas have been cultivated for thousands of years and were first domesticated around 7,000 BCE in the Near East, including regions such as modern-day Turkey, Syria, and Iraq.
• The green pea is considered one of the first “superfoods” historically, due to its high protein content.
• Peas are a rich source of antioxidants, which help in reducing inflammation and protecting against chronic diseases, and also contain high levels of phytochemical substances, including isoflavones, lectins, and saponins, which help prevent and inhibit cancer.
• Peas played a crucial role in the discovery of genetic principles. Gregor Mendel, the Father of Genetics, conducted experiments with pea plants that led to the identification of dominant and recessive genes, thus establishing the foundation of modern genetics.
• Peas, like other legumes, can improve soil fertility by fixing atmospheric nitrogen through a symbiotic relationship with Rhizobium bacteria in their root nodules. This process converts nitrogen into a usable form, enriching the soil and benefiting subsequent crops..

Types of Edible Peas

There are three main types of edible peas: garden peas, snow peas, and sugar snap peas.

1. Garden Peas (Pisum sativum) – Also known as green peas or English peas, these have sweet, starchy peas inside tough, inedible pods. The peas grow inside green, rounded pods that are typically 7-10 cm (3-4 in) long. The peas need to be shelled before eating, as the pods are not edible.
2. Snow Peas (Pisum sativum var. macrocarpon) – Known for their flat, wide, edible pods that are sweet and crunchy. Snow peas have flat pods with very small peas inside. The entire pod is edible, though the tough “strings” along the edges are often removed. Snow peas can be eaten raw or cooked, and are popular in stir-fry dishes.
3. Sugar Snap Peas (Pisum sativum var. saccharatum) – These are a cross between garden peas and snow peas, with sweet, crunchy, rounded edible pods. Snap peas, also known as sugar snap peas, have thick, rounded pods that can be eaten whole. They combine the sweetness of garden peas with the crunch of snow peas. Introduced in 1979, they are easy to grow and can be enjoyed raw or cooked.

Each type offers a unique flavour and texture, making them versatile additions to various recipes and enjoyable both raw and cooked.

Determinate and Indeterminate Pea Plants

Pea plants can be classified into two types based on their growth habits: determinate (bush or dwarf) and indeterminate (climbing) varieties. Here’s a detailed explanation of their botanical differences and characteristics:

Determinate Pea Plants (Bush or Dwarf Peas)

• Growth Habit: Determinate peas, also known as bush or dwarf peas, have a compact growth form. They grow to a predetermined height, typically ranging from 30 to 100 cm (1 to 3 ft). Once they reach their mature height, they stop growing vertically and focus on producing flowers and pods.
• Botanical Differences:
  • Stem Structure: Bush peas have shorter internodes (the segments between leaf nodes on the stem), which limits their vertical growth.
  • Growth Cycle: They have a concentrated growth and production period, often maturing earlier than climbing varieties.
  • Root System: Their root systems are generally shallower and more spread out, which is suitable for container gardening.
• Support: While some bush pea varieties remain quite low and may not require support, others can grow up to 70-100 cm (2-3 ft) and may benefit from staking or small supports to keep the plants upright.
• Ideal Use: Bush peas are ideal for growing in pots and containers due to their compact size and limited need for vertical space.

Indeterminate Pea Plants (Climbing Peas)

• Growth Habit: Indeterminate peas, also known as climbing peas, have an extended growth pattern. They continue to grow taller throughout the growing season, often reaching heights of up to 2 meters (6.5 ft) or more. Their growth doesn’t stop once they start flowering; they can produce pods over an extended period.
• Botanical Differences:
  • Stem Structure: Climbing peas have longer internodes, which allow for continuous vertical growth. They produce tendrils that help the plants climb.
  • Growth Cycle: These peas have a longer growing and harvesting period, making them suitable for continuous production throughout the season.
  • Root System: Climbing peas typically develop deeper root systems that support their vigorous vertical growth.
• Support: They require structures like trellises, teepees, or other forms of support for optimal growth. Vertical supports help manage their height and make harvesting easier.
• Ideal Use: Climbing peas are perfect for vertical gardening, maximising productivity in small spaces by allowing multiple plants to grow on the same support structure.

Both types offer unique advantages depending on garden space and growing preferences, making them versatile options for gardeners.

Basic Growing Information

• Sun Requirements: Full sun
• Water Requirements: Medium
• Soil Types and Properties: Fertile, well-draining, loamy soil with plenty of organic matter
• Soil pH: 6.0-7.5
• Pot Size for Container Growing: 30 cm diameter

Planting

Peas are a cool-season crop, thriving in temperatures between 13-18°C (55-65°F). They can tolerate frosts down to -6.5°C (20°F). They are typically planted in early spring in regions with cold winters, or in late summer to autumn in areas with mild winters, to avoid the stress of high summer heat.

Seeds should be sown directly into the soil when the soil temperature is at least 5°C (41°F). To improve drainage in compacted soil, mix in some compost, as peas are sensitive to waterlogged conditions, often referred to as “wet feet.”

Sow pea seeds at a depth of approximately three times their diameter. At a soil temperature of 15.5°C (60°F), seedlings will typically emerge in 9-13 days. Peas need well-drained soil or a raised bed to prevent excessive moisture, which they cannot tolerate.

After planting and the first initial watering, it is best to avoid further watering until the seedlings have emerged, as overwatering can cause the seeds to rot in the soil.

• Best Time to Plant
  o Climates with freezing winters: Sow in early spring, as soon as the soil can be worked, and the risk of hard frost has passed.
  o Climates with milder winters: Sow in autumn or winter, allowing the plants to establish during the cool season and mature before the heat of late spring or summer.

Note: Check gardening calendars for the best planting times in your location

• Spacing: 5-8 cm (2-3 in) between plants, 45 cm (18 in) between rows
• Seed Sowing Method: Sow seeds directly into the ground
• Seed Sowing Depth: 2.5 cm (1 in)
• Time to Harvest: 9-11 weeks when planted from seed
• Mature Height/Spread: Up to 2 meters tall, depending on the variety
• Grown From: Seeds

Care and Maintenance

• Watering Tips: Water regularly but avoid waterlogging. As peas are susceptible to powdery mildew, it is best to water them early in the day and to water the soil near their roots, without wetting their leaves.
• Fertilisation: Apply a balanced fertiliser once a month
• Pruning: Not necessary
• Support: Use stakes or trellises for climbing varieties

To support climbing pea varieties, construct sturdy structures such as trellises, teepees, or netting.

• Begin by installing vertical poles or stakes approximately 2 meters (6.5 ft) tall into the ground. For a trellis, stretch mesh or wire horizontally between the poles, creating a grid for the peas to climb.
• Alternatively, create a teepee by arranging several poles in a conical shape, tying them together at the top. Secure netting or twine along the structure to provide additional gripping points for the tendrils.
• Ensure the supports are firmly anchored to withstand the weight of the mature plants. The plants will begin to grow around the structures, using tendrils to grip around the support.

Growing Difficulty

• Easy to Grow

Growing Tips

• Keep the soil consistently moist during the flowering and pod development stages.
• Once the pea plants start producing, pick the pods daily to increase production.

Companion Plants

• Good companion plants include: carrots, corn, cucumbers, radishes, turnips
• Avoid planting near: members of the Allium (onion) family such as onions, shallots and garlic, as their roots exude antibiotic compounds into the soil which inhibit the beneficial symbiotic nitrogen-fixing bacteria that live in the nodules of the roots of leguminous plants.

Common Pests and Diseases

• Pests: Aphids, pea weevils
  • Prevention and control methods: Use insecticidal soaps or grow flowering companion plants nearby to attract natural predators such as ladybirds (ladybugs), lacewings and hoverflies.

• Diseases: Powdery mildew, root rot
  • Prevention and control methods: Ensure good air circulation and avoid overhead watering.

How to Control Powdery Mildew on Peas

Symptoms: Powdery mildew appears as yellow spots on the upper surfaces of leaves, which develop into powdery gray-white patches that can coalesce to cover the entire plant. In severe infections, the plant may appear light blue or gray.

Cause: The fungus Erysiphe pisi, which causes powdery mildew, overwinters on plant debris or alternate hosts. The disease is favored by warm, dry weather combined with cool nights that lead to dew formation.

Management:

• Plant Resistant Varieties: Choose pea varieties that are resistant to powdery mildew, especially if planting later in the season.
• Early Planting: Plant peas as early as possible to reduce the likelihood of infection.
• Irrigation: Use overhead irrigation to help wash the fungus off the leaves and reduce its viability.
• Sulphur Applications: Apply wettable sulphur spray regularly if the infestation is severe, as it can help control the spread of the fungus.
• Clean Debris: Remove and destroy infected plant debris to prevent the fungus from overwintering.

Proper management practices, including choosing the right varieties and maintaining good garden hygiene, can significantly reduce the impact of powdery mildew on pea plants.

Harvesting

• Harvest Time: When pods are swollen but not yet ripe
• Harvesting Tips: Pick regularly to encourage more pods to develop.

Peas are most flavourful and taste best when harvested young. Allowing them to mature for too long can result in the pods developing tough, stringy fibres along the top seam. To remove these fibres, snap off the stem end of the pod and pull the stringy fibre away along the seam.

Propagation

• Produce New Plants From: Seeds

Culinary Uses

Peas are a highly versatile ingredient that can be enjoyed fresh, frozen, or dried, making them a staple in various cuisines around the world. Here’s a deeper dive into their culinary uses:

Fresh Peas

• Young Seeds and Pods: Fresh peas, including the seeds and pods, are tender and sweet, making them ideal for eating raw or lightly cooked. Garden peas (green peas) are often shelled and added to salads, soups, and casseroles, providing a burst of flavor and a bright green color.
• Snow and Snap Peas: Snow peas and sugar snap peas can be consumed whole, including the pods. They are excellent in stir-fries, salads, or simply steamed with a bit of butter and seasoning.

Frozen Peas

• Convenience: Frozen peas retain much of their nutritional value and sweetness, making them a convenient option for cooking. They can be quickly added to a variety of dishes, such as soups, stews, risottos, and pastas, often needing just a brief reheating to be ready to eat.
• Storage: Keeping frozen peas on hand is a practical way to enjoy their flavour and benefits year-round, regardless of their growing season.

Dried Peas

• Storage and Use: Dried peas, like split peas, are commonly used in soups and purees. They are starchy and have a fuller flavour compared to fresh or frozen peas, adding a hearty texture to dishes such as split pea soup or pea porridge.
• Preparation: Dried peas need to be soaked before cooking to rehydrate them and reduce cooking time, making them suitable for long-simmered dishes.

Microgreens

• Pea Shoots: Pea shoots, harvested as microgreens, are the tender young leaves and tendrils of the pea plant. They are packed with flavor and nutrition, offering a delicate, fresh taste reminiscent of young peas.
• Uses: Pea shoots can be used as a garnish or added to salads, sandwiches, and wraps for a crunchy, sweet element. They are also great in stir-fries and as a topping for soups and other dishes, adding both visual appeal and a burst of flavour.
• Growing: Growing pea shoots is simple and can be done indoors or outdoors in a shallow tray. They are ready to harvest in just a couple of weeks, making them a quick and easy way to enjoy fresh greens.

General Tips

• Seasoning: Peas pair well with a variety of seasonings and herbs such as mint, thyme, and dill. They can also be enhanced with butter, lemon, garlic, or onions.
• Combination: They complement many other vegetables, including carrots, potatoes, and corn, and can also be combined with proteins like chicken, ham, or seafood in various recipes.

Note: Peas contain anti-nutrients like phytic acid and lectins, which can interfere with the absorption of certain nutrients, such as iron. However, cooking peas or using preparation methods such as soaking can significantly reduce their anti-nutrient content, making them easier to digest and safer to eat. While most people consume cooked peas, some types, like snap peas, can be eaten raw. Raw peas contain higher levels of anti-nutrients and can be harder to digest, potentially causing digestive discomfort if eaten in large quantities.

In summary, growing peas is rewarding due to their versatility and ease of growing. They offer high nutritional value and can enhance your garden’s fertility, making them a great choice for both new and experienced gardeners. Enjoy the crisp, sweet taste of fresh peas straight from the plant!