Sweet peas are one of the most rewarding cut flower a home gardener can grow. The nostalgic scent of sweet peas is enough reason to try sowing a few plants in your own garden, not to mention the multitude of varieties that fill seed catalouges. From frilly bold blossoms to tiny bonnet shaped blooms, its easy to get carried away and end up with more seeds then sense!
Sweet peas require a little planning to get the most bang for your buck, but the early effort will promise you bloom after bloom of scented flowers from early June up until at least the autumn equinox.
Last year on the farm we tried two methods of sowing, single seedling and double sown seeds. We found that the double sown seeds in 7cm pots grew just as fast and produced as many flowers than single sown plants in smaller pots. Early pinching is key for maximum blooms as it encourages side branching and more vigorus flowering. It seems a little daunting at first to take the heads off your little seedlings but dont worry. You’ll be amazed with your plants come early summer!
Sweet peas can be grown by the no dig method if you are a good planner! Spread a good layer (8cm deep) of manure and compost where you’d like your trelisses in late autumn, cover with mulch and leave until spring. Follow the steps below then you can plant straight into prepared rows when the time comes.
Another trick is to soak and presprout your seeds. This is to ensure every seed sprouts. Not every variety germinates well so presprouting means every seed you have sown is gauranteed to grow into a healthy vine. Otherwise, you might end up with only half your seeds growing and needing to resow another batch.
We sow our sweet peas in January-February and bring them on indoors or under a cold frame outdoors. Sweet pea plants are very hardy and will withstand snow and a moderate freeze. Sowing early insures a good root system to produce vigorous growth come summer time
Growing Sweet Peas
What you need:
- Sweet pea seeds
- Bowl for soaking
- Paper towels
- Plastic bags
- 7cm wide pots
- Tray for holding pots
- Seeding compost
- Capilliary matting (optional)
- Manure and good compost
- Trellis stakes at least 2 meters tall
- Twine, heavy wire or chicken wire for supporting plants up trellis
Soaking and Presprouting:
Soak each variety of seed in a small bowl of cold water over night. Try soaking 30-50% more seeds than you need
Once seeds have soaked, lay them in a wet paper towel and fold over the seeds so they are completely covered. Place in a loosely sealed plastic bag. Find a warm spot in you house, we used our hot press, and leave for 2 days. After 2 days check your seeds daily for sprouting and make sure paper towel stays damp.
Sowing seeds: Once you see sprouts from your seeds you are ready to sow into pots. Sweet peas have a large root system so try to find the deepest pot possible (around 10cm deep). Fill each pot with seeding compost and compact firmly to 2 cm below top of pot. (Dont under fill your pots to save compost, this restricts nutrients to your plants. They need as much as they can get)
Place two seeds per pot on opposite sides of pot then spread a thin layer of compost and press in gently. Cut your capilliary matting to over hang the tray on one end, place matting into your tray and arrange you pots. Label and date each variety!
Capilliary matting (above) is optional but ensures your seeds stay watered if you leave them for a few days. Just top up the water container before leaving.
Leave your tray on a window sill in a sunny room. In one weeks time the seeds should all be pushing through the soil.
This is the hardest part of growing seedlings. It feels counterintuitive to chop each seedling down, but this step is crucial to growing strong plants with side branches that produce more flowers.
Once your plants are about 10cm tall pinch each groing tip back to around 6cm. In about two weeks the plants will start sending side shoots and become bushier.
Dont let your seedlings dry out and keep sheltered in a coldframe or windowsill until your are ready to start hardening off. During this time mice will find sweet pea seedlings irresistable, if keeping outdoors protect you sweet peas with a fine wire mesh or grow indoors. If mice do get to your sweet peas, you may be surprised to see your plants bounce back rather quickly if not too much has been eaten! (It happened to our seedlings last year and we still had bucket loads of blooms)
It’s a good idea to harden off your plants before transplanting. About two weeks prior to planting out, get your plants used to being outside for a few hours in a sheltered spot. Increase the amount of time each day until you have them out overnight.
Preparing trench for planting:
Once you’ve started hardening off it’s a good idea to dig and prepare your trench for growing.
Dig a 30cm deep trench about 2 meters long. Place a few trowels full of manure and top up with good compost.
Drive in your trellis stakes about 30cm deep, on both ends of your trench. Attach your twine or wire runnif across the two trellis stakes about every 30cm up your stakes. You can also staple gun chicken wire across the stakes (preferable for more support).
Healthy root devlopement ⬆️
The day has come around early May after most frosts have passed! You can plants your hardened off plants about 20cm apart down the trellis. Dig a small hole and plant the whole pot with both plants together in the same hole. You should have some impressive root growth at this point! Firm the plants in well and water daily. Sweet peas love water!
Growing, feeding and harvesting:
Apply organic slug pellets or coffee grounds to ward off slugs. You might have to do a nightly inspection until plants take off with strong growth.
Feed your plants weekly with a good organic plant feed, you can also use nettle and seaweed fertilizer. We will be posting a how to make your own later this Spring!
Once plants start growing strong tie your plants to the trellis every 30 cm. They can grow that fast each week!
Our plants in early July
Once blooming begins around mid June cut every bloom before seed pods form. This will keep your plants blooming until late october weather permitting!
One days harvest from 50 plants
Homemade garlic spray or neem oil will ward off green fly. Coffee grounds help with slugs when spread thickly around young plants.