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Sweet Pea Royal Mix

Lathyrus odoratus 'Royal Mix'

The epitome of old-fashioned garden romance, these climbing beauties produce intensely fragrant ruffled flowers that perfume the entire garden on cool mornings. Their sweet scent and pastel colors make them irresistible for cutting gardens and cottage garden schemes.

Harvest

65-75d

Days to harvest

📅

Sun

Full sun

☀️

Zones

2–11

USDA hardiness

🗺️

Height

3-8 feet

📏

Planting Timeline

Zone:

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Start Indoors

Transplant

Direct Sow

Start Indoors

Transplant

Direct Sow

Showing dates for Sweet Pea Royal Mix in USDA Zone 7

All Zone 7 flower →

Zone Map

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Sweet Pea Royal Mix · Zones 2–11

What grows well in Zone 7? →

Growing Details

Difficulty

Moderate

Spacing4-6 inches

SoilRich, well-drained, alkaline preferred

pH7.0-7.5

WaterConsistent moisture, 1-2 inches per week

SeasonCool season annual

FlavorNot edible - contains toxic compounds

ColorMix of pink, purple, white, lavender, and salmon

Size1-2 inches across

Zone-by-Zone Planting Calendar

Zone	Indoor Start	Transplant	Direct Sow	Harvest
Zone 3	April – May	June – July	June – August	—
Zone 4	March – April	June – June	June – July	—
Zone 5	March – April	May – June	May – July	—
Zone 6	March – April	May – June	May – July	—
Zone 7	February – March	April – May	April – June	—
Zone 8	February – March	April – May	April – June	—
Zone 9	January – February	March – April	March – May	—
Zone 10	January – January	February – March	February – April	—

Complete Growing Guide

Light: Full sun (6 or more hours of direct sunlight a day). Soil: High Organic Matter. Drainage: Good Drainage, Moist. Height: 3 ft. 0 in. - 8 ft. 0 in.. Spread: 2 ft. 0 in. - 3 ft. 0 in.. Spacing: 3 feet-6 feet. Growth rate: Rapid. Maintenance: Medium. Propagation: Seed. Regions: Coastal, Mountains, Piedmont.

Harvesting

Type: Legume.

Bloom time: Spring, Summer

Edibility: Sweet pea fruits are inedible and poisonous to humans.

Storage & Preservation

Sweet Pea Royal Mix flowers are grown purely for their ornamental beauty and intoxicating fragrance—never consume any part of these plants as they contain toxic alkaloids. Fresh cut flowers should be placed immediately in cool water and stored in a cool location away from direct sunlight.

For longest vase life, recut stems under running water and change vase water every 2-3 days. Flowers typically last 5-7 days when properly cared for. To preserve their incredible fragrance, harvest flowers at peak bloom and dry them quickly using silica gel or by hanging small bundles in a warm, dry, dark location. Dried sweet pea flowers retain much of their scent for 6-8 months when stored in airtight containers, making them excellent for potpourri and sachets. The papery seed pods that follow can be saved for next year's planting if allowed to fully mature on the vine.

History & Origin

Origin: Southern Italy, Sicily, Crete

Advantages

+Attracts: Butterflies
+Edible: Sweet pea fruits are inedible and poisonous to humans.
+Fast-growing

Considerations

-Toxic (Seeds): Low severity

Companion Plants

Plant Together

Marigolds

Repel aphids, whiteflies, and other pests that commonly attack sweet peas

Nasturtiums

Act as trap crops for aphids and cucumber beetles, drawing pests away from sweet peas

Alyssum

Attracts beneficial insects like hoverflies and parasitic wasps that control sweet pea pests

Lavender

Repels moths and other flying insects while attracting pollinators

Cornflowers

Attract beneficial insects and provide complementary blue colors to sweet pea blooms

Beans

Fix nitrogen in soil which sweet peas can utilize, both being legumes with similar growing habits

Calendula

Attract beneficial insects and may help deter aphids and other soft-bodied pests

Cosmos

Attract beneficial insects and provide structural diversity without competing for resources

Keep Apart

Black Walnut

Releases juglone toxin which inhibits growth and can kill sweet peas

Sunflowers

Compete heavily for nutrients and water, and may release allelopathic compounds

Eucalyptus

Releases allelopathic compounds that inhibit germination and growth of sweet peas

Nutrition Facts

Calories

15kcal(1%)

Protein

1.03g(2%)

Carbs

3.28g(1%)

Fat

0.07g(0%)

Vitamin C

28mg(31%)

Vitamin A

97mcg(11%)

Iron

0.7mg(4%)

Calcium

39mg(3%)

Potassium

173mg(4%)

Per 100g serving. % Daily Value based on 2,000 calorie diet. Source: USDA FoodData Central (FDC #169270)

Pests & Disease Resistance

Resistance

Susceptible to powdery mildew and root rot in hot, humid conditions

Common Pests

Aphids, spider mites, slugs

Diseases

Powdery mildew, root rot, fusarium wilt

Frequently Asked Questions

How long do Sweet Pea Royal Mix take to bloom from seed?▼

Sweet Pea Royal Mix typically begins flowering 65-75 days from germination when grown in cool spring conditions. In zones 3-6, expect blooms from late May through July when planted in early spring. Warmer zones 7-9 should plant in fall for winter/early spring blooming before heat stops flower production.

Can you grow Sweet Pea Royal Mix in containers?▼

Yes, but use large containers at least 18 inches deep and 12 inches wide to accommodate their extensive root system. Provide sturdy support structures as they climb 6-8 feet. Container growing works best in cool climates and requires consistent watering since potted plants dry out faster than garden plantings.

Are Sweet Pea Royal Mix flowers poisonous?▼

Yes, all parts of sweet pea plants contain toxic alkaloids and should never be consumed. They're grown solely for ornamental purposes and cutting gardens. Keep away from children and pets who might be tempted to eat the colorful flowers. This is different from edible pea flowers from vegetable pea plants.

When should I plant Sweet Pea Royal Mix seeds?▼

Plant 4-6 weeks before your last frost date when soil temperatures are 45-55°F. In northern zones (3-6), plant in early spring for summer blooms. Southern gardeners (zones 7-9) should plant in fall for winter/early spring flowering, as sweet peas stop blooming when temperatures exceed 80°F consistently.

Why won't my Sweet Pea Royal Mix germinate?▼

Poor germination usually results from soil being too warm (above 60°F), failure to soak hard seeds overnight before planting, or planting too late in the season. Sweet peas require cool, moist conditions and their hard seed coats need pre-soaking. Plant earlier in the season when soil is naturally cool from winter.

How do you keep Sweet Pea Royal Mix blooming longer?▼

Harvest flowers daily to prevent seed formation, provide afternoon shade in hot climates, maintain consistent soil moisture with mulch, and feed monthly with low-nitrogen fertilizer. Most importantly, keep roots cool with thick mulch—once soil heats up consistently above 70°F, blooming typically stops regardless of other care.