How to grow petunias from seed

If you’re looking for an easy way to add some color to your garden, consider growing petunias from seed. Petunias are a versatile flower that can be grown in a variety of settings, and they come in a range of colors and sizes. You can buy petunia seeds at most garden stores, or online, and the process of growing them is simple. In this blog post, we’ll outline the steps you need to take to grow petunias from seed. So, if you’re ready to add some vibrant blooms to your landscape, keep reading!

Things You Will Need:

– Seeds

– Containers with drainage holes at the bottom

– Soil mix for seedlings

– Mason jar or plastic bag to hold soil mix while germinating seeds

– Transparent container to place mason jar in while germinating seeds (if you are using a transparent mason jar)

– Hanging basket with peat moss / soil mixture inside of it

– Spray bottle filled will water (See more detailed instructions below)


– When transplanting, always use a larger pot as this will make it easier to give your plant the water and sunlight it needs.

– If you are planning on growing different types of petunia from seed, remember to label them before you plant them! This way you’ll know what color they should grow into.

Germinating Your Petunias:

– Fill your seed starting pot with moist soil. It is important to make sure that the soil is well-draining, as petunias do not like wet feet. You can use a commercially available seed starting mix, or you can make your own by mixing one part garden soil, one part peat moss and one part perlite.

– Plant two petunia seeds about 1/2 inch deep in the center of each pot, spacing them apart evenly. Cover the seeds with more soil.

– Place pots in an area where they will receive bright light (although direct sunlight may be too intense for young plants) and maintain a steady temperature around 20°C (68°F). Seeds should germinate within seven days.

– Once seedlings appear, remove any lower leaves that turn yellow or brown. Petunias do not need these lower leaves to grow, and they should be removed to give the plant more energy to focus on growing upwards and producing flowers.

– Feed young plants with a diluted liquid fertilizer once every two weeks (follow the instructions on the label). If you are using an organic fertilizer, feed your plants about half as much.

Watering Your Seedlings:

– Make sure that soil always stays moist, but do not let it get soggy. You can test if the soil is too dry by performing the ” finger test.” Stick your finger into the dirt up your second knuckle – if it’s dry, add water. If it’s moist, hold off until the soil dries out a bit more.

– Keep pets and kids away from seedlings while they are young, as they can easily damage or uproot them.

Growing Your Petunias:

– Once your petunia seedlings have developed two sets of true leaves (the first pair was just seed leaves), repot them into a larger container filled with potting soil. They should be able to live in this new pot for several months before needing to be repotted again. You may notice that some lower leaves begin to yellow and die at this stage – these also should be removed.

– Allow the surface of the soil to dry between watering, but make sure that the soil is always moist at a depth of about 10 centimeters (four inches). During their active growing season, petunias should be watered at least once per day.

– Petunias are heavy feeders, so they will need frequent fertilizing throughout their growing period. You can use a commercial fertilizer or compost tea to water your plants with every second time you water them. If you are using an organic fertilize r, feed your plants half as much as directed on the label.

Caring For Your Flowers:

– Petunia flowers should appear within six weeks of sowing the seeds. Once they begin blooming, pinch off any flower buds that develop before they open to promote continuous flowering.

-If you are growing petunia plants in hanging baskets, make sure to inspect them at least once a week. Check underneath the leaves for any pests or disease and remove any that you find immediately.

– When the first frost hits your area, provide your petunias with some winter protection. Petunias do not tolerate frost well, so cover them with a sheet if they are outdoors or keep them indoors until the threat of cold weather has passed.

– Since many flower buds are produced during the plant’s first year of growth, it is important to deadhead spent blooms on young plants so that they may produce more flowers. If you allow these spent blooms to remain on your plant, it will divert energy away from producing new blooms, and may keep the plant from flowering at all.

– During the winter, you can recycle your petunia plants by propagating them. Simply separate a few of their roots into individual clumps during the spring or fall and repot each one in its own container filled with potting soil. You should have a handful of new plants for your garden come next summer!

Planting the Hanging Basket:

– Fill a hanging basket with a mixture of 3 parts soil and 1 part peat moss.

– Dig a hole in the center of the pot.

– Placing the petunia seeds from earlier, sideways, into the hole so they are buried at least one centimeter deep. You should have space for about eight seeds around the rim of the pot.

– Once this is done, water your seedlings to help them take root. Keep an eye on watering needs throughout your plant’s growth process, as petunias do not like wet feet!


– If you are using the translucent mason jar method, place your seeds in a cool place (but not in the fridge) for five days before planting them. This should initiate the germination process.

– High heat and bright light can cause petunia seedlings to wilt rapidly. Make sure that young plants get enough water, but that they aren’t sitting in water or getting too much sun while their roots establish themselves!


-Petunias are the perfect summer flowers; versatile, vibrant, and easy to grow. These plants can grow in hanging baskets, window boxes, garden beds or even flowerpots- wherever there is enough room to allow their roots to extend into the soil.

-The most difficult part of growing petunias is getting started! Make sure that you have the right kind of potting mix before planting your seedlings and choose a location with plenty of sunlight for your flowering beauties to prosper.

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