If the rose is considered the queen of the garden, then the petunia can deservedly be called the empress of urban flower beds. Even in the extreme conditions of scorching sun, dust, and frequent drought, it manages not just to grow, but to bloom luxuriantly and colorfully. And in a garden with careful care, it delights from spring practically until the first frosts.
Nevertheless, even such an undemanding plant will appreciate attention and care. And if you bring it indoors during the autumn cool-down, it will continue to bloom right up to the New Year. What you need to do for this and how to extend the flowering of petunias in pots - read on.
Table of contents
When and How Long Petunias Bloom
Petunia seeds are very small, microscopic. Sowing them directly into open ground is impractical and difficult in terms of further care. Therefore, this flower is grown through seedlings. Seeds are sown in March, and by early May the seedlings are transplanted into flower beds. Most seedlings already have flowers at this point. Petunias bloom abundantly and luxuriantly, despite heat, wind, or lack of moisture. Flowering continues right up to the frosts and stops only because the plants simply die from the cold.
How to Properly Care for Petunias During Blooming
Even such a hardy plant requires care. The actions are simple, and if performed, there will be many flowers. Let's see what exactly petunias need for healthy and lush flowering.
A Spacious Pot
Petunias have a powerful root system with many small roots, so they should not be overcrowded when planted in a flower bed. With overcrowding, the bushes will suppress each other, and this will inevitably affect flowering - there will be fewer flowers, and they will be smaller. For balcony plants, you need to choose containers where the roots won't be cramped. Typically, this is at least 3 liters, but preferably 5 liters per plant. No more than three plants are planted in large balcony boxes with a volume of 10 liters.
Note. Large cascade and ampelous varieties of petunias require even more space. Such plants are planted one per container with a volume of 10 liters.
Some gardeners believe this is unnecessary and that a 1-2 liter container is sufficient for a petunia. If you have limited space but want to decorate your balcony, you can try this. But in this case, ensure abundant and frequent feeding for the flowers. However, even then, be prepared for less lush flowering.
Quality Soil
Like all cultures of the Solanaceae family, petunias heavily deplete the soil, taking many nutrients from it. Therefore, they need rich and fertile soil. In fertile soil, roots develop quickly and well, the plant forms strong and produces many large and beautiful flowers. Furthermore, the soil must be loose and breathable, not compact from frequent watering, allow excess water to pass through well, and yet remain moist.
The soil mix for petunias is made from garden soil, peat, and humus in a ratio of 3:2:1. A small amount of wood ash is added, which serves as a potassium fertilizer and improves the quality and brightness of flowering.
Proper Watering
Despite its drought tolerance, petunia still needs regular and abundant watering, especially in the heat. With a lack of moisture, the shoots wilt and weaken, flowers fall off, and new ones do not set. Therefore, petunias should be watered daily as the soil dries out. Usually, this is 1-2 times a day. Balcony flowers and those standing under awnings do not receive natural precipitation, unlike those planted in a flower bed, so their condition must be monitored especially carefully and watered abundantly. Use clean, settled water at room temperature.
Overmoistening and water stagnation are even more harmful to petunias than drought. The roots quickly rot, plants start to get sick and may die. Therefore, when planting, it is important to ensure that the containers have large drainage holes and to pour a layer of pebbles, expanded clay, broken bricks, or other drainage material.
Attention! Water petunias only at the root. Unlike most flower crops, overhead sprinkling is not beneficial for either the flowers or the foliage.
Ideal Conditions
Petunias love the sun. This is the first and essential condition for getting beautiful flowers. In partial shade, the plants will be more modest and will not grow to their full potential. The culture is very hardy, so it feels great even in the scorching sun. Don't be afraid to place it on the most illuminated spot on the balcony or plant it in a flower bed that gets direct sunlight from morning till evening - it will only benefit.
Regarding neighbors, petunias are undemanding; they grow well next to many cultures. A wonderful combination is achieved with geraniums, marigolds, snapdragons, ageratum, verbena, coleus, lobelia, stock, calendula, cineraria, and many other flowers. However, it is worth considering the large size of the petunia's root system and not planting it next to cultures with more powerful roots, as they will suppress each other. Also, do not plant petunias next to relatives from the Solanaceae family (e.g., peppers, aubergines, potatoes, tomatoes) - related cultures are affected by the same diseases and pests.
Another mandatory condition is regularity of care. It is important not to be lazy and inspect the plantings daily to water, feed, and shape the bushes on time. Read how to do this in the next section.
How to Extend the Flowering of Petunias in Pots
Every gardener wants not only to cultivate a beautiful garden but also to increase the decorativeness and prolong the flowering of their favorite cultures. To make petunias bloom longer and more beautifully, there are various measures.
Removing Faded Flowers
This is not difficult at all, though perhaps tedious, but very important. When a flower stalk fades, a seed pod begins to form in its place. This process takes a lot of energy from the plant, as it prepares for reproduction. If you want petunias to bloom long and abundantly, you cannot allow seeds to form and ripen. Daily, you need to inspect the bushes and remove wilted flowers. Then the plants will set more and more new buds.
If you need seeds, you can grow them in autumn on the last flower stalks. However, you should know that you won't be able to get them from hybrid varieties in any case.
Fertilizing
Fertilizer application is one of the most mandatory activities, since petunias, like all solanaceous crops, need a large amount of nutrients. Even if you initially create a rich, nutritious soil, you still cannot do without fertilizing later. For plants grown in pots, boxes, and planters, this is especially important, as the volume of soil there is limited and depletes faster than in flower beds.
Fertilizers are applied several times per season:
- first time - two weeks after planting the seedlings;
- second time - during mass formation of flower stalks;
- subsequently - every 10 days.
Petunias are fed with ready-made complex fertilizers for flowering plants. The main elements in them are potassium and phosphorus, which ensure lush and bright flowering. A small share of nitrogen is also necessary so that the bushes are strong and healthy. However, it is important to maintain a balance here, otherwise plants overfed with nitrogen will only grow dense greenery and bloom little.
Petunias also need iron. Its deficiency is fraught with chlorosis - a disease in which chlorophyll formation in the leaves is disrupted. The foliage begins to turn yellow and fall off, the tops of the shoots dry up, and the roots gradually die off. To prevent this, petunias are fed with iron-containing preparations - such as chelated iron - 3-4 times per season.
Attention! A reliable way to enhance petunia flowering is to spray the bushes with monopotassium phosphate.
Spraying with biostimulants, for example, those based on seaweed extracts, is also beneficial for petunias. Such products support the plant's vitality and help it resist adverse natural factors. One foliar treatment per month is enough to keep the plant in good shape.
Any fertilizers are diluted according to the instructions and applied after watering to avoid burning the roots. It is better to do this in the evening - liquid that gets on the foliage under the influence of sunlight can cause burns.
Shaping
This procedure not only gives the bushes an aesthetic appearance but also prolongs and improves flowering. Pruning and pinching are used for this. The first pruning is done at the seedling stage. In the stage of several leaves, the tops are cut off all plants above the 4-5th leaf with sharp, disinfected scissors. This will prevent the shoots from stretching and will be the key to forming a lush bush and abundant flowering in the future.
Pinching the top point serves as a signal for the plant to grow side shoots, on which many more buds are formed than without pinching. The flowers themselves grow larger, brighter, and bloom longer.
Petunia varieties are divided into bush, cascade, and ampelous. Accordingly, they are shaped differently.
It is believed that three pinchings are enough for bush petunias. In practice, however, this is done as needed. This way you can form bushes of the desired shape and size. Hybrid petunias are easier to shape than varietal ones, as hybrids are initially predisposed to a spherical bush shape.
Important! Although pinching and shaping stimulate and improve the formation of new buds, the procedure delays flowering by 1-2 weeks.
Ampelous and cascade varieties are climbing plants with long shoots. They are usually planted in hanging baskets, from which the flowering vines hang and look very decorative. They are not formed into lush bushes. But overly elongated shoots look untidy and bloom worse, so they are pinched from time to time.
Is It Possible to Resume Flowering if the Petunia Has Finished Blooming
Petunia is an annual plant, so by the end of summer it naturally begins to fade. However, there is a way to extend its flowering period. For this, a so-called haircut is used. The shoots are cut by a third, leaving about 4-5 cm, watered, and complex fertilizers for flowering plants are applied. In 1-2 weeks, new greenery will grow, buds will begin to set again, and the bushes will "rejuvenate".
Interesting fact! Experienced gardeners who love to experiment dig up petunias from the flower bed when the cold sets in and bring them indoors. Although the plant's life cycle is limited to one season, it can be slightly extended this way.
Tips from Experienced Gardeners
Attention and conscientious care are the main things petunias need, like any flower. But there are also some nuances that help grow beautiful flowering plants. Experienced gardeners willingly share them:
- Petunia seedlings need acidic soil. For sowing and further growing, you can take special soil for cacti or simply acidify the existing soil mixture. You can add a little pine needle mulch or ericaceous compost.
- When picking seedlings, it's better not to pinch the root to avoid harming the small seedlings. The root system of petunias grows well without this technique.
- Stretching of shoots is a sure sign that the plants lack light. Abundant lighting is necessary for petunias at all stages of development, so with early sowing of seeds (in February), the lack of sun is compensated by supplementary lighting with fluorescent or LED lamps. This is especially relevant when seedlings are placed on north or east-facing windows.
- You cannot grow healthy and strong plants without hardening, especially in cooler European climates. The sprouts are taken out to a cool room with a temperature of about +10°C first for 15 minutes, then adding 5 minutes each day. Hardening strengthens the plants' immunity and prepares them for temperature changes.
- Do not plant petunias densely even at the seedling stage. Even if you pinch the seedlings correctly and on time, they will have little space to grow into lush bushes.
Conclusion
Petunias are great not only for their abundant flowering but also because a lack of attention can be compensated for at any stage of their cultivation. If the plant has wilted, it is enough to resume regular watering, and it will quickly recover. Weak flowering is stimulated by fertilizing and pinching. And if the life cycle of the bush is coming to an end, it can be extended by rejuvenating it with a haircut and changing the flower bed for home conditions.