Petunia Care For Commercial Growers

Are you adding Petunias to your commercial greenhouse growing program? Our Petunia seedlings and rooted cuttings arrive ready to be transplanted into your final containers. Follow the tips in this short guide on Petunia care to successfully finish and sell your starter plants.

You will learn:

• The basics of transplanting, fertilizing, and finishing Petunia liners
• How to time your starter plants
• How to coach customers to succeed in growing their new plants

Your customers will love the easy care, bright colors, and garden benefits of this classic annual flower. We offer several hybrid cultivars in a wide array of colors to best suit the needs of your greenhouse and customers. 

How to Transplant, Fertilize, and Finish Petunias

Each Petunia variety may vary slightly in its fertilizer, pH, and space needs. Check the NC Farms webpage for the variety you’re purchasing for details specific to that Petunia cultivar. Follow these general guidelines for success with any Petunia variety and adjust as needed for hybrid varieties.

Plant one seedling or rooted plug per 1801 cell or 4-inch container or three to four per 10-inch basket. Use well-drained soil and plant each plug centered or evenly spaced in the container. Petunia is a wonderful addition to mixed containers and hanging baskets or to small containers for landscape and garden planting. Space containers for adequate airflow and sunlight penetration around the base and foliage of each plant. Space cellpacks and 4-inch containers 8″ apart and 10-inch baskets 24″ apart.

Petunias generally don’t need to be pinched, but may be pinched once after they’re established in your final container. Some varieties benefit from deadheading, while others are self-cleaning.

Control growth and habit primarily with proper fertilizing, light, and temperatures. Petunia responds to Daminozide before buds emerge or to B-Nine at 2,500-3,500 ppm or Bonzi at 5-15 ppm, depending on the cultivar. 

Maintain daytime temperatures of 68-70℉ and nighttime temperatures of 58-60℉, with daylight extension to 14 hours at 4,000-6,000 fc. Petunia grows best in cool temperatures, high light, and moderately dry soil.

For best results, use 150-200 ppm N fertilizer constant feed and maintain an EC of 1.5-2.0 mS/cm and pH of 5.4-6.0. Alternate potassium-based and calcium-nitrate-based fertilizers and apply additional magnesium sulfate and iron chelate once or twice each.

Watch for signs of Botrytis and Rhizoctonia, especially during short days and under low light or high humidity. Use preventative measures in your commercial greenhouse. Practice good sanitation, water at the base of each plant, allow the soil to dry between waterings, and provide good airflow in your greenhouse. Space containers for adequate circulation and sunlight penetration around the base of each plant. Scout for aphids and thrips as well.

Starter Plant Timing

For 1801s and 4-inch containers up to one-gallon containers, start one plug per container 4-8 weeks before you make them available to customers. Starter timing depends on the cultivar and container size. For 10-inch baskets, grow three or four plugs per container, allowing 6-10 weeks before they’re available to customers. 

Petunias are a classic low-maintenance flower for spring sales programs.

Varieties of Petunia

We offer 16 varieties of Petunia with a wide range of colors and sizes. 

Flowers vary in color from basic white, red, pink, orange, purple, blue, and yellow, to multi-colored and striped varieties. Plants range in size and habit from the short, spreading Easy Wave cultivar to the large, mounded Surfinia XXL, with many options in between.

How Your Customers Can Use Petunias

Customers frequently look for a healthy, colorful selection of Petunias in the spring. They love options for landscaping and hanging baskets to bring long-lasting annual color to the garden, patio, and yard. Petunias attract bees, butterflies, and hummingbirds, and make an excellent addition to vegetable gardens as they repel common pests. 

Bring cheer and whimsy to window boxes, hanging baskets, or combination containers with unique colors and patterns from a wide array of available Petunia cultivars. Try the Celebrity series for superior weather tolerance or the Double Cascade varieties for a unique flower type. 

Create an enticing flower garden by growing Petunia with a mix of Marigold, Verbena, Salvia, Lobelia, Alyssum, Geranium, Nicotiana, Calibrachoa, Aster, Daisy, Snapdragon, and Lantana.

Space plants 10-20″ apart in the ground or containers in a sunny location. Water regularly and deadhead blooms to encourage continuous blooming. 

Petunias bring an easy splash of vibrant color to the greenhouse and garden! With some careful petunia care, you can enjoy the benefits these wonderful plants add to your commercial greenhouse selection!