How to Grow Petunias at Home - Care of Petunias

Wikifarmer

Editorial team

5 min read
How to Grow Petunias at Home - Care of Petunias

If you are planning to grow petunias at home, here are some easy steps you can follow.

Start Petunias from Seeds

One method is to start petunias from seeds. If you plan to follow this method, keep in mind that it is important to buy certified seeds and flower soil mix from a legitimate seller.  You may plant your petunias seeds late in winter or early spring when extremely low temperatures and frosts have passed.

Before you plant them in a pot or a hanging basket, make sure the pots have holes at the bottom. This step is crucial to protect seeds or young plants from rotting due to improper drainage.  A common technique is to place some pumice, pearlite or gravel at the bottom of the pot and above them put the soil for better drainage and aeration.

Straight on top of gravel comes the soil and then it's time for the seeds. You may sow two or more seeds in each pot, depending on your preferences and of course the petunia type. Generally, keep in mind that grandifloras need extra space to expand. We can just leave the petunia seeds at the surface, without digging them into the soil.

During the first stages of plant growth,  the soil needs to be constantly wet but not soggy, so that the seeds can sprout. Be careful though, not to over- irrigate, in order to avoid rotting.

Petunia seeds need light in order to germinate, so you can search for a sunny place. About 2-3 weeks after sowing, some baby plants will show up.

Start petunias from cuttings

The most commonly used method is to start your petunias from cuttings. In fact, this method is the quickest and the most affordable. You can effortlessly grow petunias from cuttings by following some simple steps.

First and foremost, we may choose a beautiful healthy petunia to be our mother plant. We can cut a healthy young ( not woody) sprout with a length of 4 inches (10 centimeters). Then, we can remove any leaves at the bottom ⅔ of the cutting.

Before you plant the cutting in soil, you have to help it root. To do so, a commonly used technique is to place the cutting first in a glass of water up to the plants half. Some days later, roots will normally appear. To boost rooting, you may consider the use of rooting hormones such as IAA, which of course is not essential. The next step is to plant the rooted cutting in a pot with flower soil mix and perlite or gravel for proper aeration.

Many producers claim that sunlight is what makes petunias produce bright- colored flowers. This is why they place the cuttings in sunny areas. Furthermore, in order to help your plants produce beautiful flowers, a commonly used technique is to remove old flowers (deadheading). This way the plant has more nutrients to deliver to new ones.

Buy a petunia plant

Finally, If you do not consider starting petunias from seeds or cuttings, but you still want to enjoy their amazing flowers, you may buy a petunia plant (almost 8 weeks old) from your local garden shop. At this stage, petunia plants are ready for transplanting.

A common technique is to put some pumice, perlite or gravel at the bottom of the pot or hanging basket, for proper aeration followed by the soil. Again, it is crucial to be sure your pot has holes at the bottom.

You can put soil up to ¾ of the pot, and plant the petunia without removing the existing soil from the pot you bought it in. You can fill with soil up to the top of the pot and gently press it. Irrigation needs range from 1 to 5 irrigation sessions per week, depending on the variety and the weather conditions. In general, the soil has to be constantly moist but not over irrigated.

Grow Petunias

How to take care of Petunias

Petunia Climate Requirements

Petunia has high needs in daily sun exposure in order to develop properly (6-8 hours daily). Shadow is generally causing plants to bloom less. The flowers that manage to grow under sun scarcity are of lower quality.  In most cases, the plant prefers warm and moderate dry climates and sunny summers. Rain can harm petunias delicate flowers. The plant prefers average temperatures of 65-75 °F  (17-23 °C). Petunia originated from South America where the average temperatures are 59-86 °F (15-30 °C) during the summer and rarely falls below 32 °F (0°C) in winter. The plant can, however, tolerate temperatures up to 95 °F ( 35 °C) and close to 32 °F (0 °C).

Petunia Soil Requirements

In general, soil type is not a restriction factor when growing petunias. The plants can develop well in the average soil. They prefer light, well-drained soil, slightly acid (6-7)  pH levels. Some professional growers claim that they grow petunias in soil pH 5,5 to 6 so that the plants can have intense bright flowers.

Petunias Water Requirements - Irrigation Of Petunias

Similar to other plants, petunias do not like either dry or extra wet soil. Instead, they prefer slightly moist soil at all times.  A wise technique to understand whether petunias need irrigation  is to simply touch the soil. You may try to form a ‘soil ball’ with your hand. If the soil can not be formed and crumbs, then it is time to irrigate.

Generally, most growers irrigate their petunias 1 to 3 times per week. However, keep in mind that if you consider to start your petunias from seeds, you may need to provide extra water, in order to help the seeds sprout.

Petunia Fertilizer Requirements

Most growers help their garden petunias grow faster by adding balanced liquid fertilizer of Nitrogen- Phosphorus- Potassium (10-10-10  12-12-12 or 15-15-15) once a month. Some growers, however, prefer slow-release (4 months) granular fertilizers especially designed for petunias.

Deadheading.

A common technique that many petunia gardeners use in order to enjoy petunia flowers at all times is called deadheading. With deadheading, we simply refer to the pruning of the mature flowers or the green pots containing seeds during the petunia growing period. If we don’t deadhead those mature flowers or the green pots that are often located behind the flowers, the plant will start dedicating most of its energy in order to produce seeds, and hence it will stop flowering.

This simple technique will expand the petunias blooming period, while -at the same time -will lead to bigger and brighter flowers.

Petunia Pest 

Common Petunia Problems

  • Caterpillars

Caterpillars are easily observed with the naked eye. They can live from 2 up to 6 weeks and start to attack petunias in early spring. They can damage foliage by chewing it.

  • Mites

Mites are tiny pests that look like microscopic spiders.  In spring, adults mites visit petunia leaves and suck chlorophyll from their shells. Symptoms of mites infection include unthrifty plants with curled and discolored foliage. Some producers use oils as prevention and repression measures. You may consult your local licensed agronomist.