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How to Plant, Grow, and Harvest Sweet Peas

growing sweet peas

Sweet peas, scientifically known as Lathyrus odoratus, are popular flowering plants appreciated for their colorful, fragrant blooms. These climbing plants originated from the Mediterranean region, but they're now grown worldwide, enhancing gardens with their charming flowers that span a wide array of colors.

Sweet peas come in a variety of types, but some of the most popular include 'Spencer' types known for their large, frilly blooms, and 'Bijou' types, which are more suited to container gardening due to their compact size. 'Multiflora' types that produce an abundance of smaller flowers are favored for cut flower arrangements.

In addition to their aesthetic appeal, sweet peas are also loved by gardeners for their sweet, enchanting scent. Each color and variety brings with it a slightly different fragrance, making a mix of sweet peas a true delight for the senses.

Growing sweet peas in your own garden can be a gratifying pursuit. Not only will you be rewarded with an ongoing supply of beautiful, fragrant flowers throughout the growing season, but the sight of these climbing plants covered in blooms can truly be a centerpiece in any garden space.

In the upcoming sections, we'll delve into how you can plant, grow, and harvest sweet peas in your own garden, ensuring that you're never short of these delightful flowers, whether they're gracing your garden or brightening up your home as cut flowers.

Optimal growing conditions for sweet peas - Climate, sunlight, and soil requirements Optimal

Sweet peas thrive best when given the right conditions. This section will guide you through the optimal climate, sunlight, and soil conditions for growing robust and vibrant sweet peas.


Sweet peas prefer a cool and temperate climate. They can tolerate frost and in fact, cooler weather intensifies their fragrant scent. For most varieties, it's best to sow sweet pea seeds in the early spring once the danger of frost has passed.


Sweet peas require plenty of sunlight to flourish. A location with full sun or partial shade is ideal. Aim for at least six hours of direct sunlight daily for best results.


Sweet peas prefer fertile, well-drained soil. They appreciate a slightly alkaline pH level, between 7.0 and 7.5. Adding organic compost or well-rotted manure can improve soil fertility and structure. The soil should be deep, as sweet peas develop a strong root system.


While sweet peas are reasonably drought-tolerant once established, they will do best with regular watering. The soil should be kept moist but not waterlogged.


Given that sweet peas are climbing plants, they will need some form of support to grow optimally. This could be a trellis, fence, or stakes with netting.

Step-by-step Guide to Planting Sweet Peas

growing sweet peas

When to Plant – Best time of the year for planting sweet peas

Identifying the right time to plant your sweet peas can greatly impact their growth and flowering success. This section will guide you on the optimal planting time for these charming blooms.

Sweet peas are usually planted from seed and, being cool-season plants, they prefer to start growing in cooler weather. Here are some general guidelines:

1. Cooler Climates: In regions with cooler climates, sweet pea seeds can be sown outdoors as soon as the soil can be worked in the early spring, usually between February and April.

2. Warmer Climates: For areas with warmer winters, sweet peas can be planted in the late fall to allow them to establish over the winter and bloom early in spring.

3. Indoor Start: If you want a head start on the growing season, or if your spring weather is unpredictable, you can start sweet peas indoors 6-8 weeks before the last expected frost date. They can then be transplanted outdoors once the weather stabilizes.

Remember, sweet peas are relatively hardy and can tolerate light frosts, but young plants can be susceptible to heavy frosts. It's always a good idea to have some form of frost protection available, like a horticultural fleece, if an unexpected late frost is forecast.

Seed Selection – Choosing the right seeds for your garden

Selecting the right sweet pea seeds for your garden is crucial in achieving a successful harvest. This section will guide you through the process of choosing the most suitable variety for your specific needs.

Sweet pea seeds come in a wide range of varieties, each with its unique color, flower form, and fragrance. Here are some factors to consider when choosing your seeds:

1. Garden Space: If you have ample space and can provide tall supports, consider vining varieties that can grow up to six feet tall, such as 'Spencer' types. If you're working with a smaller area or containers, consider bush or dwarf varieties like 'Cupid' that stay under three feet.

2. Color and Fragrance: Sweet peas come in a spectrum of colors, from white and pastels to deep blues and purples. Choose colors that complement your garden's design. Additionally, not all sweet peas have the same fragrance. If scent is important to you, look for varieties known for their strong fragrance, such as 'High Scent' or 'April in Paris'.

3. Purpose: If you intend to use your sweet peas for cut flowers, opt for varieties that have long stems and good vase life. 'Spencer' and 'Multiflora' types are often favored by florists.

4. Local Climate: Some varieties of sweet peas are more tolerant to heat or cold than others. Select a variety that is suitable for your local climate conditions.

5. Disease Resistance: Look for varieties that are resistant to common sweet pea diseases, such as powdery mildew and fusarium wilt.

Remember to buy your seeds from reputable seed companies to ensure high-quality seeds that will germinate well and grow into healthy plants.

Site Preparation – How to prepare the garden bed or pot for planting

growing sweet peas

Proper site preparation is essential to create an ideal growing environment for your sweet peas. This section will guide you through the process of preparing your garden bed or pot for planting.

Garden Bed Preparation

1. Select a Suitable Site: Sweet peas require a sunny or partially shaded location with good air circulation. Ensure the site gets at least six hours of sunlight each day.

2. Prepare the Soil: Sweet peas prefer deep, rich, and well-draining soil with a slightly alkaline pH. If the soil in your garden is heavy clay or sandy, improve its texture and fertility by adding plenty of well-rotted compost or manure. This should be done a few weeks before planting to allow the organic matter to break down.

3. Check Soil pH: The ideal pH for sweet peas is between 7.0 and 7.5. If your soil is too acidic, you can add lime to raise the pH.

4. Set Up Supports: Since sweet peas are climbing plants, you'll need to set up supports before planting. This could be a trellis, netting, or pea sticks.

Pot Preparation

If you're growing sweet peas in pots, choose a deep container to accommodate their extensive root system. The pot should have good drainage to prevent waterlogging.

1. Choose the Right Pot: Containers should be at least 12 inches deep.

2. Potting Mix: Fill the pot with a high-quality potting mix, which often has better drainage than garden soil. You can add some slow-release granular fertilizer to the mix.

3. Supports: Even in pots, sweet peas will need some form of support. A small trellis or bamboo stakes can work well in a pot.

By preparing your site properly, you set the stage for your sweet peas to thrive.

Planting Process - Detailed Steps on How to Plant Seeds or Seedlings

Planting your sweet peas correctly is a crucial step in ensuring a successful growth and blooming process. In this section, we'll outline the detailed steps on how to plant sweet pea seeds or seedlings.

Planting from Seeds

1. Soak the Seeds: To speed up germination, soak sweet pea seeds in water for 24 hours prior to planting.

2. Sow the Seeds: Plant the seeds about 1 inch deep and 3 inches apart in the prepared soil. If you're planting in rows, make sure to leave about 2 feet between the rows to allow for growth and air circulation.

3. Watering: Water the seeds thoroughly after planting. Keep the soil evenly moist until the seeds germinate.

Planting Seedlings

If you're starting with sweet pea seedlings, whether you've started them indoors or purchased them, here are the steps:

1. Hardening Off: If your seedlings were started indoors, gradually expose them to outdoor conditions over a week to acclimate them before transplanting into the garden.

2. Transplanting: Dig holes that are deep and wide enough to accommodate the root ball of your seedlings. Space the holes about 6 inches apart. Gently place the seedlings in the holes, fill in with soil, and firm gently around the base of the seedlings.

3. Watering: Water the seedlings thoroughly after planting, and keep the soil consistently moist.

Remember, whether you're planting seeds or seedlings, ensure that the supports are already in place to avoid damaging the roots later on.

Care for Growing Sweet Peas

growing sweet peas

Watering – How often and how much to water the plants

Watering your sweet peas appropriately is key to their growth and bloom. This section provides guidelines on the frequency and quantity of watering necessary for healthy sweet peas.

Frequency of Watering

Sweet peas prefer consistently moist soil, especially when they are young and establishing. They should be watered thoroughly at least once a week, and possibly more frequently during dry or hot periods.

Quantity of Water

When watering, ensure that the water reaches deep into the soil to encourage the development of a robust root system. The soil should be moist but not waterlogged, as overwatering can cause root rot.

Watering Tips

1. Morning Watering: Watering in the morning allows the plants to take up the water before the midday sun can cause evaporation.

2. Mulching: Mulching around the base of the plants can help to conserve moisture, regulate soil temperature, and prevent the growth of weeds.

3. Avoid Wetting Leaves: Whenever possible, water at the base of the plants to avoid wetting the foliage, which can promote disease.

Remember, while consistent watering is crucial, overwatering can be as harmful as underwatering. Always check the soil moisture levels before watering and adjust your watering schedule based on weather conditions and soil type.

Fertilizing – The type of fertilizer needed and how to apply it

Proper fertilization is a crucial part of sweet pea care. This section will guide you on choosing the right type of fertilizer and its application process.

Sweet peas are moderately heavy feeders and benefit from regular feeding. Here are the guidelines for fertilizing sweet peas:

1. Type of Fertilizer: Use a balanced, all-purpose garden fertilizer with a ratio like 10-10-10 (Nitrogen-Phosphorus-Potassium). For organic options, well-rotted compost or manure can work well.

2. When to Fertilize: Start feeding when the sweet peas have developed their second set of true leaves and then every 4 weeks throughout the growing season.

3. How to Apply: Follow the instructions on the fertilizer package for the correct amount. Always water the soil before applying granular fertilizer to prevent root burn. Spread the fertilizer around the base of the plants, avoiding direct contact with the stems or leaves.

4. Additional Feeding: Sweet peas also benefit from a high potash feed (like tomato feed) once the first buds appear, to encourage abundant, healthy blooms.

Remember, while fertilizing is important, over-fertilization can be harmful, leading to excessive foliage growth at the expense of flowers, or even damage to the plants. Always follow the recommended application rates and consider the nutrients already present in your soil.

Disease and Pest Control – Common diseases and pests that can affect sweet peas, and how to manage them

Sweet peas, like any other plants, can be affected by a range of diseases and pests. This section provides an overview of common problems and offers tips on how to manage and prevent them.


1. Powdery Mildew: This fungal disease causes a white powdery growth on the leaves and stems. To prevent it, provide good air circulation and avoid wetting the foliage when watering. Fungicides can also be used if the problem persists.

2. Root Rot: This typically occurs in waterlogged soils. Ensure good drainage and avoid overwatering to prevent this disease.

3. Mosaic Virus: Symptoms include mottled leaves and stunted growth. There's no cure for this disease, so affected plants should be removed and destroyed. Avoid planting in the same area the following year.


1. Aphids: These small insects suck sap from the plants, causing deformed leaves and reduced growth. They can be controlled with insecticidal soap or by encouraging beneficial insects like ladybugs that prey on aphids.

2. Slugs and Snails: These pests love young sweet pea shoots. Use organic slug pellets, barriers, or traps to control them.

3. Birds: Birds can be a nuisance as they like to peck at the sweet pea flowers. Netting or scare devices can be used to keep them away.

Remember, a healthy plant is the best defense against diseases and pests. Regularly check your plants for signs of trouble, and take action as soon as possible to prevent the problem from spreading.

Harvesting Sweet Peas

growing sweet peas

When to Harvest – Identifying signs that the sweet peas is ready for harvesting

Harvesting sweet peas at the right time is crucial for the best fragrance and flower quality. This section will guide you on identifying the signs that your sweet peas are ready for harvesting.

Sweet peas are usually ready to be harvested about 12 to 16 weeks after planting, depending on the variety and the growing conditions. Here are some signs that your sweet peas are ready to be picked:

1. Flower Appearance: Harvest the flowers when they are fully opened but before they start to show signs of wilting or discoloration.

2. Petal Texture: The petals of the sweet pea flowers should feel firm and crisp to the touch. If they feel soft or limp, the flowers are past their prime.

3. Number of Petals Open: Sweet pea flowers usually have three 'standard' petals at the top of the flower. When all these are open and laying flat, this indicates the flower is ready for picking.

Remember, sweet peas benefit from regular harvesting. The more you pick, the more flowers the plant will produce. If you allow the flowers to form seed pods, the plant will stop producing new flowers.

How to Harvest – Techniques for harvesting sweet peas to prevent damage to the plant and fruit

Harvesting sweet peas correctly will not only ensure the longevity and quality of your cut flowers but also encourage the plant to produce more blooms. Here's how to go about it:

1. Use Sharp Tools: Use sharp, clean secateurs or scissors to cut the flower stems. This will create a clean cut that heals quickly and is less likely to invite disease.

2. Cut Long Stems: Try to cut long stems (about 6-8 inches) when harvesting sweet peas. Cut the stem just above a leaf joint, as this is where new blooms will form.

3. Handle with Care: Be gentle when picking sweet peas. Rough handling can bruise the blooms and diminish their quality.

4. Harvest Regularly: Harvest sweet peas regularly, ideally every 2-3 days. This encourages more flowering and prevents seed formation which can reduce bloom production.

5. Best Time of Day: The best time to pick sweet peas is in the morning or late evening when temperatures are cooler. The flowers will last longer if harvested when they're not stressed by heat.

Remember, the more you pick, the more your sweet peas will bloom. Regularly removing spent flowers also helps to keep the plants looking tidy and encourages more flower production.

Post-Harvest Care and Storage – How to store and preserve sweet peas for maximum freshness and longevity

Once you've harvested your sweet peas, the next step is to ensure they remain fresh for as long as possible. This section will guide you on the post-harvest care and storage of sweet peas.

1. Immediate Care: As soon as you've cut your sweet peas, place them in a bucket of room-temperature water. This will prevent wilting and help the flowers retain their vibrant colors.

2. Remove Lower Leaves: Strip all leaves that will be below the water level in the vase. This prevents the water from becoming contaminated, which could shorten the life of your flowers.

3. Water Change: Change the water in the vase daily. This helps to keep the sweet peas fresh and extends their vase life.

4. Keep Cool: Keep the vase in a cool location, out of direct sunlight and away from ripening fruit, which can emit ethylene gas that shortens the life of cut flowers.

5. Refresh Cut Ends: Every few days, re-cut the stems under water to ensure they can take up water effectively.

Remember, the key to keeping cut flowers like sweet peas fresh is hydration. By following these steps, you can enjoy your beautiful, fragrant sweet pea flowers for a week or longer.

Frequently Asked Questions (FAQ)

How long does it take for sweet peas to grow?

Sweet peas typically take around 60 to 70 days to go from planting to bloom, depending on the variety and the growing conditions. This time frame includes about 10 to 14 days for germination, and then another 50 to 60 days until the plant is mature enough to start producing flowers.

However, it's essential to note that this can vary based on factors like the specific variety of sweet pea, the climate, the quality of the soil, and the amount of sunlight and water the plant receives.

Recap and Final Thoughts: Time to Start Planting, Growing, and Harvesting Sweet peas

You've now reached the end of our comprehensive guide on how to plant, grow, and harvest sweet peas. It's been a wonderful journey, and we hope you feel confident in your ability to cultivate these charming blooms.

1. The optimal growing conditions for sweet peas, including climate, sunlight, and soil requirements.

2. When to plant sweet peas to ensure the best yield.

3. How to select the right seeds for your garden and how to prepare your site for planting.

4. Detailed steps on the planting process and the proper way to water and fertilize your sweet peas.

5. The common diseases and pests that can affect sweet peas and how to manage them.

6. The signs that indicate when your sweet peas are ready to be harvested.

7. The proper techniques for harvesting sweet peas to prevent damage to the plant and the blooms.

8. The care and storage of your harvested sweet peas to ensure maximum freshness and longevity.

Cultivating sweet peas can be a delightful and rewarding experience. These flowers will not only add color and fragrance to your garden but can also be a source of pride as you watch the fruits of your labor grow and blossom.

Remember, gardening is a journey filled with learning and growth, much like the sweet peas you'll be cultivating. So don't hesitate to get your hands a little dirty and your heart a little excited. Your garden, brimming with sweet peas, awaits you!

In your gardening endeavors, always remember this quote by Audrey Hepburn: "To plant a garden is to believe in tomorrow." So, believe in your tomorrow, start planting your sweet peas today, and relish the joy and satisfaction that comes with watching them grow and flourish. Happy gardening!