How to Grow Sweet Peas: The Complete Sweet Pea Flower Guide (2024)

No content available.

WARNING: Do NOT plant sweet peas near edible garden peas. All parts of the sweet pea plant are poisonous. If enough of the plant is consumed, it can cause a condition called lathyrism, which is exhibited by paralysis, shallow breathing, andconvulsions.

When to Plant SweetPeas

• In most locations where frosts occur regularly (Zone 7 and colder), sweet peas should be planted in very late winter or very early spring as soon as the soil is dry enough to work. (Do not wait until thelastfrostto sow! It will likely be toolate.)
• If you garden in mild winter climates (Zones 8, 9, or 10), plant sweet peas in the late fall (November) so they can develop and bloom in late winter and early spring.To get the best display, dig a trench and fill it with well-rotted manure or compost 6 weeks before you sow the seeds. Sweet peas are greedy plants and need a good boost of nutrient rich matter tothrive.

Sowing Sweet PeasIndoors

• In the coldest parts of the country, get a jump on the season by starting sweet peas indoors in a seed tray.Sow in seed-starting containers in early spring, about 6 to 7 weeks before the last frost date, then plant out as soon as the soil can be worked; sweet peas can handle lightfrosts.
• Soaking the seeds overnight first softens the outer coating and aids germination. Lightly scoring the outer shell with a nail file can help,too.
• Sow the seeds about half an inch deep in individual cells of a seed tray—2 seeds to a module is fine, but be aware that their long roots have a tendency to tangle and can make separationdifficult.
• Once they are showing their first pea-like leaves, gently scoop them out and put them into a larger pot to harden off. The advice I had from one of the most respected sweet pea growers was “to treat the seedlings how I would my husband: stick them in an unheated greenhouse, ignore them, and they willthrive.”
• As soon as the soil can be worked, plant themoutside.

Sowing Seeds in theGround

• Sweet peas are happiest with their heads in the sun and their roots deep in cool, moist soil. When possible, plant low-growing annuals in front of them to shade theirroots.
• Choose a well-drained site. Alkaline soil is best; sprinkle some powdered lime on the surface if your soil tends to beacidic.
• Prepare a rich soil by mixing in generous amounts of compost or well-rotted manureto a depth of 2 feet. (If you want to learn more about preparing soil for planting.)
• Prior to planting, you’re going to want to dig a nice deep “compost” trench of about 4 inches indepth.
• After you dig the trench, make holes with a pencil, drop in the seeds, and press down on the soil to firm it and shut out anylight.
• Before planting, soak the seeds in water for 24 hours. Then nick the seeds with a nail file before planting to speed sprouting. You do not need to soak seeds in a temperateclimate.

Joins us as we show you how to plant sweet peas in this videodemonstration:

How to Grow SweetPeas

• Once planted, germination can take 7 to 15 days, depending on the soiltemperature.
• As seedlings emerge and grow, gradually fill in the trench. Hoe more soil up tothem.
• Keep soil moist. Summer rain may be ample. If you put your finger into the soil bed to its first joint and the soil is dry, water them at the soil level and do so in the morning; sweet peas can suffer from buddrop.
• If you use plenty of aged manure and compost when planting, you do not need to fertilize. If you do want to add nourishment, use high potash feeds, as nitrogen feeds encourage too much topgrowth.
• When plants become established, mulch well to keep the soil cool and moist. If you mulch, you may not need to water your sweet peas unless the soil getsdry.
• To encourage bushy growth, pinch off the tops when plants are 6 inches tall—not before, or you’ll encourage premature side-shootdevelopment.

ProvideSupports

• Sweet peas prefer cool days and nights and will start to fade when temperatures go above65°F.
• Except for the bush types, sweet peas are real climbers. Give them at least 6 feet of good support. Some varieties may climb to 9 or 10 feet. Other visually pleasing supports are bamboo poles in a tee-pee style, a woven willow obelisk, or a trellis. If you don’t have a fence or trellis, provide chicken wire or bushy, stubbly twigs that they can clingto.
• Tie the first few stems into the support to give the plants a good start, and the rest will follow. When they reach 4-8 inches high, pinch out the middle growing tip with your thumb and forefinger. This will lead to sturdierplants.

PickingFlowers

• Pick the flowers for bouquets often, and the plant will put energy into more blooms instead of going to seed. The more you pick, the more they produce, right until the firstfrosts.
• When the leaves start to lose their color, let a few of the last flowers form seedpods. Dry them on a windowsill and then store them in an envelope in a dry place to sow nextyear.

There are sweet pea varieties for every situation, from 8-foot-plus scramblers to dwarf bedding ones suitable for containers and borders withoutsupport.

• In their native Sicily, these ornamental peas have weak stems and anintense orange-jasmine-honey scent. Modern hybrids are stronger-stalked and have largerblooms.
• At the same time, some of these modern varieties withlarger flowers and contemporary hues lack the fragrance of the earlier sweet peas. Sweet pea ‘Cupani,’ with its bi-colored flowers, maroon upper petals with violet “wings,” is still deservedly popular and is easy togrow.
• The deliciously-scented ‘America’ is an heirloom, dating to 1896. Its petals unfurl to show stunning wavy red and whitestripes.
• Look for heirlooms like the ‘Old Spice’ collection from Sicily. This strain blooms in shades of white, cream, pink, lavender, andpurple.
• ‘April in Paris’ is a fragrant modern variety with large creamy-yellow blossoms and lilacshading.
• While the common sweet pea is an annual, there is also a perennial unscented broad-leaved everlasting pea, Lathyrus latiflolius. These clambering plants can reach up to 6 or 7 feet and are hardy to zone 5; they are low-maintenance plants that flowerregularly year onyear.

Catherine Boeckmann