Hybrid

Costa II Mix

Antirrhinum majus

Photo: AnRo0002 · Wikimedia Commons · (CC0)

Harvest

100-110d

Days to harvest

📅

Sun

Full sun to partial shade

☀️

Zones

7–10

USDA hardiness

🗺️

Height

0-3 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 Costa II Mix in USDA Zone 7

All Zone 7 flower →

Zone Map

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Costa II Mix · Zones 7–10

What grows well in Zone 7? →

Growing Details

Difficulty

Easy

Spacing12-18 inches

SoilWell-drained loam, neutral to slightly alkaline

WaterRegular, keep soil consistently moist but not waterlogged

SeasonWarm season annual

ColorRose, Silver, White, Burgundy, and Apricot

Zone-by-Zone Planting Calendar

Zone	Indoor Start	Transplant	Direct Sow	Harvest
Zone 1	May – June	July – August	July – September	—
Zone 2	April – May	June – July	June – August	—
Zone 11	January – January	January – February	January – March	—
Zone 12	January – January	January – February	January – March	—
Zone 13	January – January	January – February	January – March	—
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	—

Succession Planting

Snapdragons perform best in cool weather and slow their bloom production once daytime highs push past 80–85°F — sometimes stopping altogether. Start a first round indoors in February, transplant in April, and you'll get a solid spring flush. For a fall round, start a second batch indoors in late June or early July and transplant out in late August once the heat backs off; Costa II will carry into October or November before frost finishes it.

Don't try to succession-sow every two weeks the way you would with lettuce. The gap between indoor start and first bloom is 100–110 days, so tight intervals just mean a pile of transplants hitting the ground during the hottest part of summer. Two rounds — spring and fall — is the practical cadence for zones 7–10.

Complete Growing Guide

Exceptionally robust stems, high yields, and uniform growth in the field or greenhouse when grown under short days and low temperatures. Considered a Group 2 snapdragon. This mix includes Rose, Silver (very light pink), White, Velvet (burgundy), and Apricot. Colors are subject to change depending upon availability.Edible Flowers: The flowers are a colorful garnish for use in salads, desserts, and drinks. The flavor is floral and slightly bitter, so use sparingly. According to Johnny's Selected Seeds, Costa II Mix is 100 - 110 days to maturity, annual, hybrid (f1). Notable features: Greenhouse Performer, Use for Cut Flowers and Bouquets, Edible Flowers, Fragrant.

Light: Full sun (6 or more hours of direct sunlight a day), Partial Shade (Direct sunlight only part of the day, 2-6 hours). Soil: High Organic Matter. Drainage: Good Drainage. Height: 0 ft. 6 in. - 3 ft. 0 in.. Spread: 0 ft. 6 in. - 0 ft. 10 in.. Spacing: Less than 12 inches. Growth rate: Medium. Maintenance: Medium.

Harvesting

Costa II Mix reaches harvest at 100 - 110 days from sowing per Johnny's Selected Seeds. As an annual, harvest continues until frost ends the season.

A capsule, half hidden by calyx lobes, short-beaked.

Type: Capsule. Length: 1-3 inches.

Storage & Preservation

Costa II Mix snapdragon flowers are best kept fresh on the counter in a cool location (65-70°F) in a vase with fresh water, changing water every 2-3 days for a shelf life of 7-10 days. For refrigerated storage, place stems in water at 35-40°F to extend life to 10-14 days. For preservation: (1) Air dry by hanging bundles upside down in a warm, dry location for 2-3 weeks to create dried flowers for arrangements; (2) Press flowers between parchment paper under heavy weights for 1-2 weeks for crafts and botanical preservation; (3) Freeze in water ice blocks for decorative use in beverages, lasting 3-4 weeks.

History & Origin

Costa II Mix is an F1 hybrid developed through controlled cross-pollination. Listed in the Johnny's Selected Seeds catalog.

Origin: Southwestern Europe

Advantages

+Exceptionally robust stems reduce need for staking or support structures
+High yields make Costa II Mix economically efficient for commercial growers
+Uniform growth simplifies scheduling and harvesting across entire production
+Short-day, low-temperature performance ideal for winter greenhouse production
+Five distinct colors in mix appeal to diverse market preferences

Considerations

-Edible flowers have floral, bitter taste requiring cautious use in cuisine
-Color availability fluctuates, potentially affecting consistency of mix composition
-Group 2 snapdragons typically susceptible to rust and powdery mildew
-Requires cooler temperatures and short days for optimal performance expression

Companion Plants

Marigolds (especially Tagetes patula) are the most practical companion here — their root secretions deter soil nematodes, and their scent does a reasonable job of confusing aphids that would otherwise find your snapdragons. Sweet alyssum is worth planting as a low border: it blooms fast, attracts hoverflies whose larvae eat aphids, and doesn't compete for root space with snapdragons at 12–18 inch spacing. Nasturtiums pull double duty as a trap crop — aphids tend to pile onto them first, which at least gives you a concentrated target rather than a scattered infestation across your whole bed.

The harmful companions are worth taking seriously. Black walnut produces juglone, a compound toxic to a wide range of plants — this is well-documented enough that NC State Extension flags it specifically; don't site snapdragons anywhere near an established walnut's drip line. Fennel suppresses its neighbors through root exudates and should live in its own isolated corner regardless of what else you're growing nearby.

Plant Together

Marigolds

Repel nematodes and aphids while attracting beneficial insects

Nasturtiums

Act as trap crops for aphids and cucumber beetles, plus attract pollinators

Sweet Alyssum

Attracts beneficial insects like lacewings and provides ground cover

Petunias

Repel aphids, tomato hornworms, and other garden pests

Zinnias

Attract butterflies and beneficial insects while providing color contrast

Lavender

Repels moths, fleas, and mosquitoes with its strong fragrance

Catnip

Repels mosquitoes, ants, and rodents more effectively than DEET

Borage

Attracts pollinators and repels tomato hornworms and cabbage worms

Keep Apart

Black Walnut

Releases juglone toxin that inhibits growth of many flowering plants

Fennel

Allelopathic compounds inhibit growth and germination of nearby plants

Eucalyptus

Strong allelopathic properties suppress growth of surrounding vegetation

Troubleshooting Costa II Mix

What you'll see, why it happens, and what to do about it.

Gray fuzzy coating on leaves or spent blooms, especially during cool, damp stretches

Likely Causes

Botrytis cinerea (gray mold) — thrives in humid, still air and loves dead flower tissue as an entry point
Plants spaced too tightly, blocking airflow between stems

What to Do

1.Deadhead spent blooms promptly — don't let them sit on the plant and rot
2.Space transplants at least 12 inches apart and thin any overcrowded stems
3.If the mold is already established, remove and bag the affected growth; don't compost it

Rust-colored powdery pustules on the undersides of leaves, often appearing mid-season

Likely Causes

Antirrhinum rust (Puccinia antirrhini) — a fungal disease specific to snapdragons, spreads via airborne spores
Overhead watering that keeps foliage wet overnight

What to Do

1.Switch to drip irrigation or water at the base in the morning so foliage dries before nightfall
2.Strip and trash (don't compost) infected leaves as soon as you spot pustules
3.Costa II is a hybrid bred with improved rust tolerance, but rotate beds annually regardless — spore load builds up in soil over successive seasons

Spindly, pale seedlings that flop over before they're 3 inches tall

Likely Causes

Damping off (Pythium or Rhizoctonia spp.) — fungal pathogens that thrive in cold, soggy seed-starting mix
Insufficient light during indoor germination — snapdragons need bright light within days of sprouting

What to Do

1.Start seeds in a well-draining, sterile seed-starting mix; keep it consistently moist but not sitting wet during the 7–10 day germination window
2.Place trays under grow lights no more than 2–3 inches above the seedlings for at least 14–16 hours a day
3.If damping off hits, pull affected seedlings immediately — the fungus moves to neighbors fast

Frequently Asked Questions

How long do Costa II Mix snapdragon flowers last in a vase?▼

Costa II Mix snapdragon flowers typically last 7-10 days in a vase at room temperature with fresh water changed every 2-3 days. In the refrigerator at 35-40°F, they can last 10-14 days. This extended vase life makes them excellent for cut flower arrangements and floral designs.

Is Costa II Mix a good snapdragon variety for beginners?▼

Yes, Costa II Mix is excellent for beginners. It's rated as an easy-to-grow hybrid with robust stems and uniform growth. It performs well in both field and greenhouse settings and produces high yields, making it reliable and forgiving for novice growers.

Can you grow Costa II Mix snapdragons in containers?▼

Yes, Costa II Mix can be grown in containers, though they perform optimally in garden beds or greenhouse settings. Use well-draining potting mix and ensure containers are at least 6-8 inches deep. Container-grown plants may require more frequent watering and regular deadheading for best blooms.

What does Costa II Mix snapdragon flowers taste like as an edible flower?▼

The flowers have a floral flavor with a slightly bitter undertone. They should be used sparingly as a colorful garnish in salads, desserts, and drinks rather than as a main flavor component. The visual appeal typically outweighs the taste in culinary applications.

When should I plant Costa II Mix snapdragons for optimal growth?▼

Costa II Mix snapdragons are Group 2 varieties that thrive under short days and low temperatures. Plant in early spring or fall for best results. They typically require 100-110 days to harvest, so time planting accordingly to align with your desired bloom period.

What light conditions does Costa II Mix need?▼

Costa II Mix snapdragons require full sun to partial shade, needing 4-6+ hours of sunlight daily. While they tolerate partial shade, full sun produces more robust stems and uniform flowering, especially in greenhouse or controlled environments.