Petunia is a genus of herbaceous perennials and semi-shrubs belonging to the Nightshade family that grows naturally in the tropics of Brazil, Argentina, Bolivia, Uruguay and Paraguay. The name of the plant comes from the Brazilian word “petun”, meaning “tobacco”, the relative of which is the petunia. One of the species can even be found in North America. There are about twenty-five species of petunias, sometimes very different from each other. Petunias have been cultivated since the 18th century. Hybrids obtained through breeding more than a century ago are grown as balcony or garden annuals. Its large, vivid blossoms attract florists, which adorn the garden or terrace with their exuberant blossoms throughout the season. They also harmonise remarkably well with other garden flowers such as pelargoniums and begonias. Ampelia petunia is very beautiful in suspended compositions of varieties of different colours. And the main reason of the popularity of this flower is the fact that it is not very difficult to plant and grow it.
What type of flower is a petunia?
The petunias are shrubby, stalked or erect, densely branched, 15 to 70 cm tall, with oval, solid petunia leaves, 5 to 12 cm long, arranged in rows, which are green or dark green. Both stems and leaves are pubescent. Flowers are funnel-shaped, solitary, on short peduncles, axillary or terminal, erect or irregular, simple or fringed, sometimes fringed.
The care of the Petunia
The petunia’s habitat in the wild is the equatorial and subequatorial belts where the countries of Latin America (Brazil, Uruguay, Paraguay, Bolivia, Argentina) are located. This is a region with a warm and humid climate. Temperatures reach 30-33C throughout the year and never drop below +10C. Under such conditions the plant shows itself as a perennial, adding brightness to the lower tropics, but in areas with snowy winters it has to be re-cultivated every season. Taking care of the southern guest is not difficult – you just need to know the basic rules and give the plants what they need.
Petunias prefer light, well-drained soil, a sunny location and plenty watering. If it is not watered sufficiently, it will quickly turn yellow. A typical 80 cm long balcony box will require approximately 4-6 litres of water on hot, sunny days. To avoid chlorosis of the petunias, add a fertiliser containing iron to the hard tap water in addition to the liquid fertiliser. Otherwise, the leaves will turn yellow in the mid-summer. White petunia varieties are particularly susceptible to chlorosis. Remove the blooms regularly and remove the withered blossoms and shoots to encourage the formation of new buds. If you want the ampelous petunias to branch better and form a lush bush, you should regularly shorten the long shoots to the fourth- fifth bud or leaf. This promotes the formation of side branches that can easily fill the gaps.
How often should a petunia flower be watered? The watering should be done under the roots so as not to damage the delicate petunia flowers. The day after watering, remove any weeds and loosen the area so that no crust is formed on the ground. But the most important thing for the beauty and flowering time of the petunias is to fertilise them sufficiently.
Does petunia flower love the sun? Petunias require bright and prolonged light, so it is advisable to choose sites on the south, southwest or southeast side, avoiding shady and cold corners. An open area far from the trees, bushes and fences is best for this plant. However, under the canopy of a veranda or pergola, the petunia will perform just as well as in direct sunlight.
How to prepare petunia flower soil? Petunias need light but moisture-retaining soil. The best soil for Petunia is a deciduous sod soil (60%) with a mixture of sand and peat (20% each). Acidic soils can be balanced by adding a little lime. If the shrub will grow in a pot or cachet, it is advisable to make a five- inch drainage layer and add hydrogel to the soil.
Does petunia flower like moisture? Moisten the soil regularly but keep it moderately moist. Short droughts and brief over- watering during the summer rains can be tolerated well, but stagnant water, especially during cold weather, can have a negative effect on the root system and reduce the decorative quality of the plant. Besides watering, the soil beneath the flower should be periodically loosened to allow air access.
What temperature is good for petunias? On sunny days, the greenhouse will need to be ajar and ventilated and the temperature inside need to be kept under +25°C. If it is too hot, the petunias will be even less tolerant than a short-term frost.
What are petunia flower pests?
Petunias are rarely affected by disease under proper cultivation, but let’s take a look at the most common diseases of these beautiful flowers. Grey and wet rot – Light brown spots appear on the leaves, flowers and stems that are later covered with a grey, fluffy coating. The plant is affected by high humidity and low temperatures (below +14°C), and by too much nitrogen fertiliser. Dense planting, excessive watering and low temperatures should be avoided. Aphids – if the plant has few pests, a strong jet of water will suffice; if the plant is heavily infested, it should be treated with a special agent. Powdery mildew – sudden changes in temperature or humidity cause a white stain to appear on the leaves and flowers. The infested parts should be removed and the plant should be treated with sulphur. Why does the petunia flower wither? >>