The Petunia is one of the most popular flowering annuals for a good reason. Petunias fragrance the air throughout the spring and into the fall with their bright colors and lively blooms. The best thing about Petunias is that they are incredibly easy to grow in the garden and greenhouse containers. Petunias come in hundreds of varieties. Depending on the size of the flower and how it grows, they can be categorized.
- Grandiflora Petunias: Among the most common types of Petunias, these are the easiest to grow. A typical size for this species is between 7.5 and 10 cm. It is common for blooms to grow upright, but they may spill over the sides of the container.
- Multiflora Petunias: Their flowers are smaller and more abundant.
- Milliflora Petunias: They are compact, reblooming miniature versions of growing Petunias.
- Spreading Petunias: Their 15 cm height allows them to cover a particular area rapidly as a blooming ground cover.
The best Petunias for growing in containers are, while others are better for massing in the garden. There really is something for everyone regarding Petunias, whether you like the old-fashioned or fancier, newer varieties.
How to Grow Petunias in a Greenhouse
Soil Requirement for Growing Petunias in the Greenhouse
Light, fertile soil with good drainage and a slight acidity are ideal for their growth. The pH should be between 6 and 6.5. Add compost or organic matter to heavy clay soils before planting. Use a free-draining soilless potting mix fortified with slow-release fertilizer when planting in containers.
Temperature and Humidity Requirement for Growing Petunias in the Greenhouse
Temperatures between 15-24°C during the day and 12-15°C at night are ideal for Petunias. Frost and freezing temperatures will damage and ultimately kill them, but they can tolerate temperatures down to about 5°C. These flowers should have low to moderate levels of humidity.
Sunlight Requirement for Growing Petunias in the Greenhouse
Petunias prefer full sun, but they can also grow in partial sun. The blooms of Petunias will likely fade more rapidly if they are grown partly shaded. Light shade during the hottest period of the day can be helpful for container-grown Petunias, especially as summer wears on and daily watering isn’t enough.
How to Grow Petunias From Seed
Most Petunia plants are purchased from nurseries as young plants. The challenge of growing Petunias from seed can be worth it, especially if you are looking for a particular variety. You should start your Petunia seeds 10 to 12 weeks before the last frost. Moreover, this process takes a long time, so make sure you have enough time. Planting Petunias from seed involves the following steps:
- If you plan to keep the Petunias in these containers beyond the growing season, prepare a shallow container of pre-moistened seed-starting mix or several small pots. There should be drainage holes in each unit and a tray to catch excess water.
- Seeds will be pressed into the mix, spaced about an inch apart, and 1/8 inch of seed starting mix will be sprinkled on top.
- The containers should be thoroughly watered and allowed to drain, discarding any excess water. After that, cover the top of the container with plastic wrap and place it in the sun.
- When sprouts appear, remove the plastic and place the seedlings under a strong grow light or in a sunny spot as soon as possible.
- Once the seedlings have grown a set of true leaves, transplant them into their own small containers with good drainage if you have used a shallow tray. Seedlings should be thinned according to the spacing recommended on the seed packet.
- Keep them moist until you are ready to plant them separately but do not let the soil waterlog. A temperature of 24°C is ideal for indoor care.
Spacing Requirements for Transplanting Petunias
Petunia spacing depends greatly on their growth habits, ultimate size, and where they are grown. You can quickly create a spectacular show by massing plants in pots and containers. In other areas, compact and upright varieties can be planted 15-20 cm apart, bushy varieties with a lax, mounding habit need a wider spacing of around 30 cm, and trailing varieties should be planted 40 cm apart.
In case you missed it: How to Grow Gerberas in Greenhouse: A Step-By-Step Guide for Seed to Harvest
Water Requirement for Growing Petunias in the Greenhouse
You should water your Petunias regularly if you want them to bloom multiple times. They are heat-tolerant, so weekly watering should be sufficient unless there is a prolonged drought in your area. In general, you should water in a way that soaks the soil about 6 to 8 inches deep. A Petunia with a spreading habit needs to be watered more frequently. Depending on their size and the soil they contain, hanging basket flowers require more frequent watering, sometimes as often as daily.
Fertilizer Requirement for Growing Petunias in the Greenhouse
Growing Petunias requires rich, organic soil that drains well. Slow-release fertilizers can also give these plants a much-needed boost to start the growing season. During the growing season, apply a fertilizer with a 10-10-10 ratio or a balanced liquid fertilizer such as Miracle Grow. Throughout the growing season, feed your plants to ensure consistent growth and lots of flowers. Fertilizing Petunias every other week will benefit them on the ground. Once a week, you can feed Petunias in pots and on the ground that are spreading.
Pruning and Deadheading in Petunia Plants
Depending on the variety you are growing, pruning may be required. Keeping grandifloras from going to seed requires the most work and frequent deadheading. Self-cleaning and spreading varieties do not require pruning or pinching. The occasional deadheading of plants will boost flower production and make the plants more full. It will encourage new growth and more branching if you cut back your plants when they get leggy and have fewer blooms.
Pest & Disease Control for Petunia Plants
Control pests and diseases with a preventive spray program. Three insect problems can affect your plants: whiteflies, leaf miners, and aphids. Botrytis, Pythium, and crown rot are among the diseases to watch out for. There can be serious consequences associated with viral diseases. Therefore, virus-free material is essential to start with. Don’t plant liners too deep in the soil. Make sure the foliage is not overly wet.
Harvesting Petunias
They range in size from 2 to 4 inches across and come in every color except brown and black. Cut-flower arrangements require proper cutting and display techniques to ensure Petunias remain attractive for as long as possible. When harvested correctly, most cut Petunias remain in bloom for six days after harvesting.
- The petals of a Petunia flower should be just beginning to spread out when you choose it. After the morning dew has dried, cut the flowers before the afternoon.
- Stems should be cut 1/4 inch above a set of leaves. The cut Petunia should be placed in a water container as soon as it is cut so it doesn’t wilt.
- Fill a vase with water that is 110 degrees Fahrenheit. Add a cut flower preservative to the water and dissolve it.
- Trim off the bottom half-inch of each Petunia stem while holding it underwater at a 45-degree angle. Place the Petunias in the prepared vase and arrange them as desired.
In case you missed it: How to Grow Gardenias/white Peony in Greenhouse: A Step-By-Step Guide for Seed to Harvest
Conclusion
Adding Petunias to your garden for a splash of color during winter is a great idea, but frost can kill seedlings when they emerge. Until the seedlings are ready for planting, you can nurture them indoors. The easiest way to provide warmth, shelter, and moisture is to use a greenhouse. Petunias can be grown in a cooler greenhouse using root-zone heating to save money and produce a quality crop.
- Ultimate Guide to Ossabaw Island Hog: Breeding, Raising, Diet, and Care
- Ultimate Guide to Juliana Pig: Raising Facts, Size, Diet, Care, and Lifespan
- Raising Lleyn Sheep: Disadvantages, Price, Uses, Characteristics, and Care
- Ultimate Guide to Meishan Pig: Breed Facts, Breeding, Raising, and Care
- Ultimate Guide to Teacup Pigs: Raising, Diet, Lifespan, Cost, and Care
- Guide to Raising Poll Dorset Sheep: Facts, Profile, Characteristics, Uses, and Care
- Ultimate Guide to Bighorn Sheep: Characteristics, Diet, Lifespan, Breeding, and Lifecycle
- Ultimate Guide to Raising Katahdin Sheep: Farming Facts, Breed Profile, Uses, and Care
- Ultimate Guide to Raising Oreo Cows: Belted Galloways Farming Facts, Profile, Uses, and Care