| Common Name | Petunia Grandiflora |
| Genus | Petunia |
| Species | P. atkinsiana or P. hybrida |
| Family | Solanaceae |
| Life Cycle | Tender Annual |
| Tray Size | 8 |
| Plug Care | Harden off and transplant or bump up into larger cells/pots soon after receiving plugs - do not allow to become rootbound. |
| Netting / Staking | One to two layers of netting is recommended to keep stems straight, otherwise they can take on a sprawling habit. |
| Temperature Range | Ideal temperature for growing is 55F to 76F. Cooler temperatures promote longer stems. They are quite hardy and can survive in the intense heat of summer if provided adequate irrigation. Can handle cooler nights in spring, but protect from any frost. |
| Spacing | 6-8"; crowded cultivation promotes longer stem length. |
| Soil Preference | Loose, well draining, fertile soil of neutral pH. Petunias can be heavy feeders and should be fertilized regularly during the growing season. An NPK ratio of 17-5-17 or 20-10-20 is recommended, and additional treatments with ammonium nitrate also promote longer stems, but are not absolutely necessary. |
| Day Length | Long day plants - long days and high light promotes flowering. Days must be longer than 13 hours to induce flowering. Plant in full sun. |
| Pinching | Pinch when plants are small to promote vigorous side branching. The more you cut, the more stems you will get. Do not allow plants to set seed or it will shorten their lifespan. |
| When to Plant | Plant in the spring, after all threat of frost has passed. Can be planted in a hoop house or in the field. They can tolerate cooler temperatures and once established are quite heat tolerant as well. |
| Harvesting | Harvest when 1-2 flowers on the stem are open and additional buds will open in the vase. Expect to see the first flowers approximately 60-70 days after transplanting into the field, however this is highly dependent on weather conditions and temperature. |
| Post Harvest Care | Cut stems should immediately be placed into cool water. Expect a vase life of over a week–foliage stays green even after flowers fade. The use of a floral preservative will increase vase life. |
| Diseases / Insects | Botrytis and rhizoctonia are the most common diseases to affect this crop. Watch closely for thrips–they will get into unopened buds and new growth tips, causing malformed flowers and damage on both flowers and foliage. |
| Bailey's Notes | "Is anyone else old enough to remember when petunias grew upright and were tall, well before 'Purple Wave' or the 'Supertunia' era? Back when you had to pinch your petunias all day long to keep their growth in check? Well these remind me of the good old days, but frillier and more double than before. Petunias WANT to be tall, we've just bred them into these little dwarf muffin shaped bedding plants, or sprawling ground covers that fill every whiskey barrel and Home Depot parking lot in America. And that's why these are so fun! Entirely unexpected." |
| Resources | NA |