Propagating petunias from seeds or cuttings - Plantura (2024)

No summer garden should be without flowering petunias. You can find out all about propagating petunias yourself from seed or by cuttings here.

Petunias (botanical name Petunia) are annual plants of South American origin, which unfortunately do not withstand our frosty temperatures in winter. Therefore, every year you need to restock your balcony with fresh plants. However, these do not necessarily have to be expensive or overwintered with great effort. You can save a lot of money by simply propagating petunias yourself. This works via cuttings, which you can easily cut from the most beautiful plants in your possession, or via seeds. When propagating by seed, new colour variations can even occur when petunia varieties are mixed together.

Propagating petunias: sowing seeds

Propagation by sowing is very successful and uncomplicated. The seeds can be bought in specialist shops. The varieties available here is usually enormous. If you already have petunias at home, you can harvest the seeds yourself. For example, salmon-coloured variety “Salmon Wave” is particularly easy to grow from seed and even rain-resistant.

Harvesting seeds

You can easily harvest the seeds of petunias yourself. To do this, proceed as follows:

• Do not remove withered flowerheads any more
• Harvest seed pod when they are light brown and closed
• Dry the capsules in a warm, airy place until they burst
• Collect the small, black seeds and store in a cool, dark place (e.g. screw jar)

The formation of the seed pods begins all by itself, as soon as you stop deadheading. The bursting of the dried seed pods begins after a few days.

Sowing petunia seeds

The seeds are sown from February onwards. If you follow a few points, you will almost certainly soon be able to enjoy small petunia seedlings.

• Fill sowing tray with germ-free sowing soil
• Mix seeds with dry quartz sand and spread evenly on the soil with sufficient spacing
• Cover seeds with a thin, permeable layer of soil at most (light germinators)
• Germination temperature: min. 20 °C
• Keep soil evenly slightly moist with water sprayer (water sprayer)
• Cover sowing tray with foil hood (from germination ventilate 1x daily)
• Bright location without direct sunlight
• From the formation of the 2nd pair of leaves: prick out or transplant individually into small pots
• Acclimatisation of the plantlets before planting outside
• Planting outdoors from mid-May (no more danger of frost)

Mixing with quartz sand is optional, but considerably simplifies the process of sowing mini seeds. A thin layer of soil over the seeds reduces the risk of mould. The foil hood provides the necessary humidity. The plantlets are acclimatised by placing them outside during the day on sunny days. You can find out which location is best for petunias from May onwards in our article on cultivating petunias.

Tip: Although petunias theoretically bloom from June until the first frost, many plants are completely exhausted by their own pace in terms of flowering and growth before then and fade prematurely. To avoid a flowerless period, some of the seeds can be sown later (April/May).

Propagating petunias by cuttings

Hanging petunia varieties are particularly suitable for propagation via cuttings, as they produce very long, strong shoots with the right care. If you proceed as follows, it will not take long for your cuttings to grow their first roots.

• The cuttings are best cut in the summer
• Use 10 cm long (preferably flowerless) shoots
• Remove all leaves and flowers (except the top pair of leaves)
• Place in a glass with lime-free water until roots have formed and then put in pots with soaked growing soil OR plant directly in the pots
• Propagation was successful when the cuttings sprout at the top
• Repot into larger planters and continue to cultivate like adult petunias
• Acclimatisation of cuttings before planting in mid-May

It may take two to three weeks for the cuttings to form sufficient roots in the glass with water. When planting directly in pots, the cuttings are simply inserted a few centimetres deep into the soil, which is then pressed down well. You can read all about the subsequent care of your own handiwork here.

Petunia varieties: a small selection

There is a huge selction of of petunia varieties available. Just as diverse are the colours in which they bloom. The flower shapes also vary. From single to double flowers, there is something for everyone. The different varieties are traditionally divided into four groups of varieties.

• Miliflora with flowers two to three centimetres in size
• Multiflora with flowers about five centimetres in size, resistant to rain
• Floribunda with flowers about eight centimetres in size
• Grandiflora with trumpet-like, rain-sensitive, very large flowers

Below is a list of particularly beautiful varieties of petunias.

• Night Sky: The large flowers of this hanging petunia are reminiscent of a purple night sky, filled with white stars. No one flower resembles the other.
• Chocolina: This variety, with its rather small, chocolate-coloured flowers, looks good enough to eat (but please, do not snack on them). It has a bushy, only slightly pendulous growth.
• Pirouette Red: Piroutte Red is a representative with double flowers and a drooping habit. The red eye is framed by a beautiful white.
• Amore® Queen of Hearts: Here the name says it all: with red hearts on a yellow background, each individual flower of the standing variety proclaims a message of love.
• Mirage Red Morn: This standing petunia will make any border shine with its red edged flowers with white eye.

Note: The most robust and easy to care for are the simple blue or purple petunias, for example, the variety Big Time Blue. These cope quite well even with wind and rain. White-flowered varieties are prone to chlorosis. Very compact and even weather-resistant are the varieties ‘Yellow Apple Bee’ and ‘Purple Balls’.

Everything you need to know about petunias – from cultivation to care to overwintering – can be found in this article.