About Petchoa ‘Caliburst Yellow’ (Petunia sp. x Calibrachoa sp.)
‘Caliburst Yellow’ is the first petchoa available from seed, combining the vibrant calibrachoa flower colors with the durability and daylength adaptability of petunias. Its mounded, spreading habit makes it exceptional for baskets, patio pots, and mixed planters. Controlled growth, a long bloom window, and cold tolerance make it a standout for early spring through autumn displays.
When to Plant Petchoa Seeds
Gardeners in all USDA Zones can start seeds indoors eight to ten weeks prior to the last expected spring frost. This allows the time needed before transplanting outdoors.
In the warmer zones of 9 and 10, cool season annual petchoa seeds can be sown in late winter for early spring blooms. Those interested in a cool season production can also begin petchoa seeds in late winter in a heated greenhouse.
Flowers initiate forming flower buds with just a nine hour daylength, allowing earlier blooming in spring compared to many calibrachoas.
Plants tolerate cool nights down to 40°F once established.
Where to Plant Petchoa Seeds
Due to the trailing habit of this plant, it is much happier in containers, baskets, and mixed planters. Use a high-quality, well-drained potting mix rich in organic matter. Maintain a pH of 5.5–5.8 to prevent iron deficiency. Ideally, keep it under full sun, but it will tolerate partially shaded locations, especially in hotter climates. Keep in mind that if grown in too much shade, petchoa plants will produce fewer flowers and will have a less compact form.
How to Plant Petchoa Seeds
Lightly moisten the soil mix. Surface-sow by pressing seeds into the medium; seeds require light to germinate. Read here for more about germination light requirements. Germination should occur in only four to eight days if maintained between 72°F and 76°F. Keep the medium evenly moist but not saturated. Do not allow the soil to dry completely.
Once growth occurs, reduce the temperature to 65°F to 70°F and slightly lower the moisture level. Apply a balanced fertilizer at a low rate.
How to Care for Petchoa
Once seedlings are established, they can be transplanted to larger containers or their final garden location. Space plants 10 to 15 inches apart in final containers or beds. Petchoa thrives between temperatures ranging from 55°F and 75°F.
Plant in a sunny location and provide water in the morning, petchoas are heavy drinkers. Pinch back plants if you want a more compact, bushy growth habit. Feed regularly to support blooming, especially in containers.