Grow petunias from seed

Windowsill gardening: how to grow your own petunias from seed

Bring a little spring into your life this week. Sow a packet of petunia seeds indoors. By following a few simple steps, you can grow strong, healthy plants that look as good as the ones you buy in May.

Start with sterile soil. This is important because regular garden soil carries fungus spores that thrive in the moist, warm environment. If the spores are not destroyed, you will have a fine crop of mold, but no petunias.

You can buy sterile soil at garden centers or the grocery store. Or you can sterilize your own by baking it in the oven at 200 degrees for 30 minutes. Don’t let the temperature get any higher, and don’t give it an extra few minutes ”just to make sure,” or you’ll kill helpful bacteria that live in the soil as well.

Now that you have the soil ready, find a container. A milk carton cut in half lengthwise is fine, and shallow aluminum pans that baked goods come in work well. Punch a few holes in the bottom so extra water can drain out. Water well and let it soak in.

With tiny seeds such as petunias, I scatter them over the surface by tearing a half-inch hole in the seed packet and tapping gently on the top while moving my hand slowly and evenly across the seedbed. You might like to practice this technique first, using an envelope and one-quarter teaspoon of salt. Do it several times on a dark-colored surface to see if the grains are well scattered.

After planting, set the container in a sunny window. Lightly cover the top with plastic wrap. Check occasionally to make sure the soil is still damp. It should be just moist, not soggy.

Seedlings will emerge in 10 to 14 days. As soon as you see them, take off the plastic wrap. Then keep them moist, but don’t drown them. You can water from the bottom by setting the container in a shallow pan of water until the top appears wet, or you can lightly mist the seedlings with a fine spray. If you choose the second method, be sure you dampen more than just the surface of the soil.

Soon you will have lots of tiny green plants.

Now comes the hard part. You’ve got to get rid of some of them if you want the rest to grow big. If you can’t bear to part with a single one – and I never can – carefully transplant the seedlings into other shallow containers.

Use a stick or sharpened pencil to separate them gently. Water well and put back in a sunny window.

Feed the seedlings once a week with Rapid-Gro or a similar fertilizer. Use two teaspoons per gallon of water, or follow the package directions.

In early May, set the young plants outdoors on a sunny porch or next to the house. If the weather gets too cold, bring them back inside at night. After a week or so of hardening off, you can set them out in the garden.

When buying petunia seeds, you will find hybrid varieties more expensive but well worth the extra price. Cascade, a grandiflora or large-flowered type, comes in a range of colors. The blooms live up to their names, cascading in masses from hanging baskets or window boxes. They are suitable for bedding, too.

Another grandiflora, Pink Magic, and its white or blue cousins, are outstanding for their early blooms. They continue to flower heavily right up to frost time in the fall. For something different, you might like to try orange-hued Tangerine or Sunburst, a yellow.

Multiflora petunias have smaller blooms, but there are lots of them, and they stand up well in unfavorable weather. Commanche, a scarlet red, and Coral Satin, a deep salmon, are both All-America winners. Sugar Plum is an especially sweet little purple variety. White Joy and its variously colored relatives are also good choices.

Finally, there are the double varieties. Most of them are a little slower to bloom and not quite as compact, but still showy for pots on the patio.

Apple, Cherry, Peach, and Snowberry Tarts look as delectable as they sound, but for showing off, you may want to try a few of the new double grandifloras. Circus, a reddish salmon and white bicolor, and Blushing Maid, a soft salmon pink, are both All-America selections of this type.

Once you have tried petunias, you can start ageratum, snapdragons, impatiens, coleus, salvia, and asters, using the same method.

Wave Petunias

Vibrant & Versatile Wave Petunias! Plant breeding excellence with extensive impact! The PanAmerican plant breeders changed the face of ornamental gardening when they introduced Wave petunias. Plant performance across all series is simply outstanding and the popularity of the Waves continues to grow. Purple Wave Classic started the spreading petunia trend more than 20 years ago. Gardeners and garden writers across the country continue to take notice. The Waves have evolved into the most outstanding petunia series ever introduced.
Landscapes of Wave petunias have little competition. Four series and a myriad of colors provide options for any setting, whether it calls for a ground-hugging carpet of color or bountiful, lush mounds of blooms. Able to bounce back quickly from adverse weather, Waves are trusted favorites in America’s parks, gardens, and landscapes. Containers on the deck are as showy as they come when planted with Wave petunias. Prolific blooms cover the spreading plant overspilling its containers, creating a true sight to behold. Hanging baskets of Waves are true show stoppers in hanging baskets, providing superior performance and can’t-look-away color. Consumers are quickly drawn to their proliferation of blooms on uniform spreading plant habits ensuring they will fly out the garden center doors. Window boxes spilling over with Waves far surpass the ordinary! Waves offer generous, color-drenched cascades of color that make simple window boxes into high-impact showpieces.

Good merchandising techniques are an essential part of any successful sales season in the garden center. Highlight your Wave display with several mature decorative planters to show gardeners the potential of these impressive varieties. These color-soaked display pots should add momentum to your Wave petunia sales.

In addition to having finished plant material on display, offer your customers
point-of-purchase sales material from PanAmerican Seed Company, breeders of the popular Wave varieties.

Gardeners seek out Waves in their trademark pink pots, and you can receive them without a royalty from PanAmerican.

Visit and take advantage of their free materials,
including banners, bench cards, plant tags and pack handles. This very attractive point-of-purchase sales support material will boost sales and give your display a professional touch…and it’s free.

Planting petunia’s from seed

Seeds are very tiny. They do not need peat pots – they transplant very well. You could even put them in little yogurt containers if you punch holes in the bottom – or old six-packs if you saved them from annuals you have bought in the past.
Here is what I did last year. I used a plastic container – like a small margarine or cool whip container – punched some holes in it. Then I put in some potting soil – and then I covered that with about 1/2 inch of seed starting mix.
Here is the directions from Stokes seeds – and I pretty much followed them – though I didn’t worry about fungicide. I ended up with containers that looked like chia pets, I had so many germinate!
We use pure Jiffy Mix in our seedling flats, rather than soil mixtures – for better germination. Fill the flat to within 1/4 in/6 mm. from the top and firm (especially the corners), so you don’t get erosion when watering. Soak the seed flat thoroughly before sowing, with luke warm water (70°F/21°C) and a good fungicide to prevent disease. Mark the rows 2 in/5 cm apart, and 1/8 in/3 mm deep, 1/2 in/13 mm wide – with the edge of a label or a marking board. If you are sowing several different colors in the same flat – it might be a good idea to place a piece of cardboard across the flat on both sides of the row that you are sowing – to prevent mixtures. Broadcast the seed as thinly as possible in each row. Press the seed firmly into the surface. We do not usually cover with soil – as some colors are light responsive. If you believe in covering the seed – use coarse vermiculite – it retains moisture and allows enough light for proper germination. To conserve moisture, cover seed flats with plastic, glass or paper. For ideal germination soil temp. must be 80° F/27° C (air temp. of 86°F/30° C days and 65° F/l 8°C nights). The soil temp. must not drop below 70° F/21°C. Use bottom heat if possible. Seed will germinate according to color (pinks, blues and whites first – reds last) in 5 – 1 0 days. Do not use cold water- it lowers the soil temp. and weakens tender seedlings. Uncover your seed bed at the first signs of germination, to prevent tall weak seedlings. Grow seedlings cool at 65°F/l8°C. Transplant 4 to 5 weeks after seeding, 1 – 1 1/2 in./3 – 4 cm. apart, and at the same depth as they were when in the seed flat. Grow at 55 – 60°F/l 3 – 1 6 °C. for stocky plants.

Saving Petunia Seeds

If you live in warmer southern climates, saving Petunia seeds will not be much of an issue for you; however, if you live in a colder climate region, then your Petunias will usually die in the winter and you will need to save Petunia seeds and re-plant the following season.
Saving Petunia Seeds – Why Save
If your Petunias are annuals rather than perennials, you need to save your Petunia seeds each year in order to avoid buying new ones.
A Note about Hybrid Petunias
Before you get started saving your Petunia seeds, you should be aware that seeds from hybrid petunias should not be saved and used for a new planting if you are looking for the same type of Petunia that the seed came from. Hybrid seeds are created by inbreeding different parent plants and can only be re-created by breeding the exact two types of parents again. However, if you’re adventurous and are willing to take a few chances, hybrid seeds can produce something unusual and very interesting.
How to Save Petunia Seeds
Petunia seeds are located in the plant’s seed pod. The seed pod is also referred to as the calyx, and is usually located at the base of the flower. You should wait until a flower dies on its own before trying to remove the seed pod from the flower. Generally speaking, it’s not a good idea to deadhead Petunia plants in order to get seeds.
Once you find a good dead flower for seeds, you’ll find the calyx located inside the sepal of the flower. You’ll recognize the calyx as a bulging part of the stem that is located directly beneath the base of the Petunia flower. After the Petunia flower dies, it will fall to the ground, and the calyx will begin to swell and turn brown. After a period of a couple of days or so, the calyx will split open and the seeds will fall out.
You can pick the calyx off the plant before it opens or tie a piece of pantyhose or other some other very light type of material to catch the calyx so that it does not hit the ground and spill its seeds. If you pick this calyx before it opens, place the paper bag placed the calyx in a paper bag for storage until it splits open.
After you have collected the seeds from the calyx, you should allow them to dry for about a week or so. You’ll be able to tell that the seed is dry if you can’t bite into it or smash it. Once the seeds are dry, store your Petunia seeds in an airtight container such as a small food jar or small Tupperware container. In order to keep the seeds dry, you can also add small packets of silica gel to absorb any moisture that might get into the container.
Once you have placed your seeds in an appropriate, airtight container, keep the seeds stored in a cool, dry place. Temperatures of around 32° to 42°F are usually best for Petunia seeds. Also, make sure to label the container so that you know what type of seeds they are.

The first thing to know before saving any seed is whether or not the parent plant is a hybrid. Most petunia plants sold in garden nurseries are hybrids, so you cannot count on what type of petunia seed they will produce. However, non-hybrid petunia seed can be purchased, such as Balcony Petunia. These are also referred to heirloom or open-pollinated seed, basically meaning the seed from the plant should germinate and grow the same type of plant as the parent plant. Some people try to give special status to “heirloom” seeds, but I figure that anything that is open-pollinated has been around a long time. (click on any photo to enlarge) Be sure to check out my first short tutorial at the end of the blog. 🙂

medium pink balcony petunia blossom

There are some open-pollinated varieties of flowers that naturally have color variations within the seed. Balcony Petunia is one of these. That is, different colors do not in this case mean differences due to hybrid manipulation and unreliable seed production. In fact, you will reliably get the different colors from these petunias.

Petunia seeds are very tiny. If they fall to the ground, they will pretty much disappear from sight. The Balcony Petunias will self-sow, but petunias are one of those flowers that I usually have specific landscaping plans for. They seem to look best in a wide swath across a flower bed. It is easier to grow a couple of flats of petunia seedlings to be able to put exactly where I want them. The volunteers can bring unexpected joy to a few other places.

vibrant petunia to empty, crisp empty seed pod on the far leftLeft to right: freshly picked petunia, still small unripe seed pod, dry pod still surrounded by green sepals, denuded crisp seed pod, empty shell of seed pod.

By the time there are some ripe seed pods on the plants, they are probably nestled lower on the plant, down under the flowers that are blooming all around the outside of the plant. Just a smidge of patience will help you find them. Just follow any stem down a ways, but do it gently so that you don’t accidentally knock seed out of pods that are staying upright or ready to pop if they feel a little bit of pressure. You will find seed pods in various stages of maturing and drying. You want the hard ones that haven’t opened yet. You might be able to find some seed in those that have opened if they haven’t succumbed to gravity. You may be able to see the the seeds sitting there like miniature caviar. (I don’t eat caviar, but that’s what they remind me of!) If they are ready, they will pour out like sand in an hourglass timer.

Here is a close up of the unripe and the freshly ripe pods. You can see how the petunia seeds are already escaping and adhering to the sticky sepals.

Some people recommend putting empty tea bags or home made mini-sacks over flowers to collect certain types of flower seed before it disperses. However, the petunias are an annual that blooms prolifically and constantly enough throughout the summer so that you can probably go out on any given day from midsummer to the first frost and find a few of the right kind of seed pods. There are enough seeds in 2-3 pods to save you a couple of dollars come spring, but you don’t have to limit yourself to that! It’s like shopping for free!

In the center of the photo is the very dry pod that is still full of seeds.And here are the seeds that came out of that pod after I easily cracked it open with my finger tips.

Below is my first ever embedded video in my blog. It is just a 40 second demo of me collecting petunia seeds recently. I’d love to hear what you think of it!

Collecting Flower Seeds: How And When To Harvest Garden Seeds

Collecting flower seeds from your favorite plants is a fun and rewarding pastime. Growing plants from seed is not only easy but also economical. Once you have the method down you will have a cost efficient way of ensuring a garden full of beautiful blooms year after year.

Seed harvesting provides an opportunity to preserve your beautiful garden flowers to replant next year or share with friends and family. Some gardeners also enjoy developing their own seed strains or hybridizing their plants by seed saving.

When to Harvest Garden Seeds

Knowing when to harvest garden seeds is the first step to saving plants for future use. Once flowers begin to fade at the close of the season, most flower seeds are ripe for picking. Seed harvesting should be

done on a dry and sunny day. Once seedpods have changed from green to brown and can be easily split, you can begin collecting flower seeds. Many people choose to gather seeds while deadheading plants in the garden.

How to Collect Flower Seeds

Always harvest seeds from your best performing plants. When you’re ready for seed harvesting, you’ll need to know the best method on how to collect flower seeds. Use clean and sharp garden scissors to cut the pods or seed heads from the plant and place them into a paper collection bag.

Label all of your bags so that you do not forget which seeds are which. It is important to use only paper bags, as seeds can spoil in plastic. Once you have collected your seeds, you can spread them out on a screen or a piece of newspaper and dry them at room temperature for a week.

How to Store Flower Seeds

So now that your seeds have been harvested, it’s time to learn how to store flower seeds to ensure they will be at their optimal best for planting next season. Brown paper bags or envelopes are great to store dry seeds. Label all envelopes accordingly.

Store seeds in a cool and dark spot for the winter. A temperature around 40 F. (5 C.) is best. Do not crush or damage seeds or allow seeds to freeze or overheat while in storage. Keep seeds dry at all times.

How to Harvest Petunia Seeds And Save Them for Future Use

The viability of petunia seeds makes them ideal for propagation purposes. You can harvest these seeds on your own, and use them for next year plantation. This Gardenerdy article provides some tips that you can follow for growing petunia seeds in your garden.

Petunias are popular among hobbyists and flower enthusiasts all over the world. They are well-known for their color diversity and low maintenance levels. You can grow petunia flowers in containers, hanging baskets, regular flower beds, and as borders in the flower garden. In all these growing choices, you will get to enjoy fragile, magnificent blooms in spring or summer season. Petunias are perennials, but mostly maintained as annuals, meaning you need to uproot plants, and replant them every year.

Similar to many other annual flowering plants, petunias produce a large quantity of viable seeds. Hence, if you are interested in harvesting petunia seeds, you can do so for using them in the next planting season. So, for first year plantation, you can purchase these seeds from shops selling garden supplies. In case, you maintain healthy petunia plants, your plants will bear attractive blooms, which mature to seeds. This article highlights on the steps starting from purchasing petunia seeds to sowing, maintaining plants, and harvesting seeds.

How to Grow Petunia Seeds

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Petunia seeds are small and difficult to handle while sowing. Considering this, most nurseries provide small plantlets for propagation. Recently, commercial seed suppliers have created pelleted seeds, that are encased in a special coating. Such pelleted seeds are larger and easy to sow. In case you are planning to collect seeds on your own, the quality of harvested petunia seeds depends largely upon how you maintain the parent plants, harvest, and store them. Mentioned below are tips that you can follow for growing petunia seeds in your garden:

Selecting the Seeds

Petunia flowers are found in a wide array of dazzling colors, both in single and multicolored varieties. A popular variety called wave petunia seed exhibits spreading and trailing growth habit. Check out the color options available in your local nursery center. You can opt for blue and pink petunia seeds to create a color pattern in your garden. Also ask the supplier about the germination rate, plant height, and disease susceptibility of the particular varieties.

Buying the Seeds

Petunia seeds are sold in small packets, each of which contains somewhere about 25 – 65 seeds. As per your preference, you can purchase pure seeds in bulk (uncoated form) or pelleted ones. Since pelleted seeds are treated and packaged, they are more expensive than regular seeds. These pelleted seeds, though costly, are easy to handle. They have a better chance of surviving and thriving under field conditions than the untreated ones.

Growing Petunia Seeds

Sow petunia seeds as soon as favorable climatic conditions arrive, either directly in flower garden or indoors in seed trays. For spring blooming cultivars, sow them indoors, 6 – 8 weeks before the first frost arrives. Cover the seeds with soil (about 1/8 inch layer), and water lightly. You can cover a plastic sheet over the pot or tray to promote quick germination. And keep it in a corner that receives indirect sunlight.

Petunia Seeds Germination

Petunia seeds germinate within 10 days after sowing, while some may take about 3 weeks. Remove the plastic sheet as soon as the seeds start sprouting. Place the seedlings in a bright area, but away from direct sunlight. The ideal temperature range to maintain seedlings is 65° F. during day and 55° F. at nighttime. You can transplant the plantlets, when they bear the true leaves.

Maintaining Petunia Plants

The petunia plantlets are ready for transplantation within 8 – 10 weeks after sowing. Harden them before transplantation by placing outdoors in bright light during day time. After frosting is over, and when the soil temperature measures 60 degrees F, transplant petunia plants in well-drained garden soil. The plants will grow to about 12 – 15 inches tall. Encourage them to bear flowers.

Harvesting the Seeds

As the petunia flowers fade and mature, they produce seeds in a seedpod at the lower portion of the flower. In order to extend flowering period, you can pinch of the flowers. Or else, allow a few of them to dieback naturally for seed harvesting. When the blooms dry out, pinch at the base, and store them in an airtight container. The pods will open and release seeds. This way, you can harvest petunia seeds.

Store these seeds in a cool and dry area, until the return of favorable growth conditions. Follow the same steps mentioned above to sow seeds of petunia, and transplant petunia plantlets. So, this was all about selecting, planting, and harvesting petunia seeds.

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