Instructions for Growing Sweet Peas

Timing

In mild areas, sow in Autumn and overwinter. In colder areas, sow 6-8 weeks before final frost date.

Temperature

Sweet peas germinate best around 55F and do not require light. Once germinated, sweet peas do their best growing between 35F - 50F. If grown under these conditions, they’ll grow deep roots and strong, stocky stems with branching leaves.

Planting Out

Sweet peas can handle cold down to 25F, so once you’re past that danger, it’s time to put them in the ground. Sweet peas are heavy feeders and dig deep for nutrients, so it’s good to dig a deep hole or trench below them and fill it with compost. Gently remove them from their pot or cell tray and fill in the soil around them pressing down to pack the soil in around the newly planted roots. Water the roots in to eliminate any air pockets that may slow transplant.

Trellising

Sweet peas are vines so they’ll climb or they’ll crawl. In order to get good flower stems, it’s best to give the vine something to climb. A bamboo tripod, or a lattice fence, or a piece of cattle panel or netting strung between two posts. Do this within a few days of transplant

Water & Fertilizer

Sweet peas will take a few weeks to re-establish in their garden bed and while they do, it’s helpful to give them a bit of fertilizer. Before flowers appear, a foliar spray of fish or kelp fertilizer once a week or so will help (although it’s not necessary if they have good soil.) Once flowers appear, if you would like to continue to fertilize, choose one with the highest potassium in the NPK ratio on the container. Water deeply at the root 2 or 3 times a week.

Pest Management

All plants have an immune system that can be assessed by the amount of certain sugars in the leaf cells. A healthy plant will be able to defend itself against pests by not attracting them at all. So setting them up well at the beginning will do an amazing job at prevention. But pests happen. The best way to manage aphids or other sweet pea loving bugs is to attract their predators. Ladybugs (and more) love aphids. Some growers will purchase beneficial insects to help mitigate pests. A strong stream of water is a deterrent as well, but I will always discourage the use of insecticides. The balance of a garden relies on so many insects that will also be damaged and I never think it’s worth it to eliminate an important part of an ecosystem..

Harvest

Harvest the flowers when the majority of blooms on the stem are open. First thing in the morning is the best time of day because it’s when they’re most naturally hyrdrated after a night of using up all that good sunshine they got during the day. Pop them into clean, cool water, and enjoy for 3 - 5 days, keeping them out of direct sunlight and away from fruit to extend vase life. At the end of the season, let a few seed pods develop and when they’re brown and nearly cracking open, collect and label your seeds for future use.