Updated at: 21-06-2022 - By: Sienna Lewis

Seed-starting season for much of North America is still a few weeks away, but there is one plant that needs a little more time to mature. Begonias are stunning annuals that thrive in the shade and are resistant to deer. They can be used in practically any landscape because of their versatility. Unlike most annual flowers, begonias can be started from seed in mid- to late January if you’d like to cultivate some of your own.

What Kind of Begonia?

The American Begonia Society, for example, has an extensive selection of unusual begonias; otherwise, you’ll only find seed packets for two types of plants: wax begonias (B. x semperflorens-cultorum) and related varieties like Benary begonias (B. x benariensis) and Dragon Wing begonias, as well as tuberous begonias, particularly B. x tuberosa and B. boliviensis.

Start Begonias From Seed With These Tips & Tricks - Hobby Farms

Wax begonias are the simplest to start from seed of the two. Tuberous begonias can be a bit challenging: they seem to falter if conditions aren’t just right.

The Right Light

Begonia seedlings develop slowly at first, so if you want to plant them in your garden the first year, you’ll need to start them as early as possible. When it comes to the Northern Hemisphere, early February — or better still, January — isn’t too early.

For seedlings that need light to germinate and thrive, it’s not ideal at that time of year when the days are still short and the sun is weak… As a result, seed germination in natural light is unpredictable and, when it does occur, is short-lived. The quality of the light and the length of the day are more easily controlled when growing begonia seedlings under a fluorescent bulb.

Tuberous begonias are considerably more difficult because, when grown in conditions of short days (less than 12 hours), they tend to produce tubers instead of the additional leaves necessary to produce the flowering plant you desire. For both growth and flowering, more than 15 hours of sunlight is ineffective at any point in time. That’s why it’s recommended to set a timer for 14-hour days to limit day duration. As a result, you can expect larger plants and more flowers in the spring and summer.

A 14-hour day is the ideal length for growing wax begonias, but they aren’t as sensitive to day length as tuberous begonias.

How to Sow Begonias

Pelletized seed is now included in the majority of begonia seed packets. Pelletized seeds, on the other hand, are more convenient to handle and distribute, but they also cost more. Pelletized seed is sometimes the sole option when it comes to begonias.

Begonia seeds should be sown in a fine potting mix (a seed blend would be ideal) that has been moistened thoroughly and allowed to drain away any excess water. It’s important that the soil is evenly moist, but it shouldn’t be waterlogged. Get rid of all the peaks and troughs in the ground.

Now, sprinkle the seeds over the top of the mixture in a uniform layer. Do your best to spread them out equally if they aren’t pelleted. Using a block of wood, gently press the seeds into the growing mix, but don’t cover them: they need light to germinate.

For best germination, sprinkle the seed container’s surface with lukewarm water and set it in a clear plastic bag or mini-greenhouse.

Using a fluorescent light, place the container about 6 to 12 inches (15-30 centimeters) below it. Its mild warmth will aid in the germination process and keep the container at a comfortable temperature. Even at night, the temperature should not fall below 70 °F (21 °C).

You should begin to see little green leaves grow between 7 to 14 days, however this may vary somewhat from time to time. When you first glance at the earth, it will appear to be covered in green moss. You’ll need a magnifying lens to see specific features. Take off the covering when the leaves are large enough to see plainly without a magnifying glass.

When the soil begins to dry out, rehydrate it with water to keep it moist at all times. Instead of watering from above with a watering can, you may find it easier to pour lukewarm water into the tray below and allow the soil to “drink” its fill of moisture.

Tuberous Begonias from Seed and Tubers. - YouTube

Move the seedlings into small pots or plug trays when they have two or three leaves. Until they recover from transplant shock, it’s best to keep them covered with a clear plastic dome or bag for a few days at a time.

The seedlings should be kept slightly damp and fed with a dilute soluble fertilizer as they grow.

Seedlings that have taken root.

At around 5 to 6 leaves, the seedlings will begin to grow faster and more vigorously. By now, they’ve become “well established,” which means they can withstand changes in temperature, moisture, and other environmental stressors. The seedlings are strong enough to stand on their own at this point and don’t require as much care.

Maintaining a moderate level of moisture in the soil is essential, even if you don’t have to water it constantly.


As soon as the weather warms up and the evenings are above 50 F (10 C), you may begin to introduce the seedlings to the outside. Some begonias can handle full sun or shade, but most prefer partial shade. If you give them a little TLC, they’ll last all summer.

Why Start Begonias From Seed

If you produce (or sell) a lot of annual flowers, growing them from seed might save you a lot of money. Annual flowers aren’t the most expensive plants in your local greenhouse. The process of starting marigold, cosmos, and salvia plants from seed is straightforward; however, the process of starting begonia plants from seed is more time consuming.

In the same way that buying transplants from a grower limits your ability to choose between varieties, planting begonias from seed means you’ll have a much wider range of options and a higher return on your investment. There are dozens of begonias to choose from when you grow them from seed, but professional producers tend to focus on just a few varieties.

How to Start Begonias From Seed

The seeds of a begonia are quite small. Each seed is about the size of a dust particle. Pelletized seeds make the task of working with such tiny seeds a little bit easier. Because of the lengthy period it takes for begonias to germinate, many home gardeners avoid planting them from seed. While raising begonias from seed is time-consuming, it’s worth it in the end.

Begonias can be started from seed in new seedling trays or flats. New or disinfected seed trays are essential since the plants are susceptible to fungal diseases like damping off and botrytis. Also, you’ll need to purchase new seed-starting potting soil that is sterile.

It’s time to sow your begonia seeds now that your seed trays are filled with sterile potting mix. In order to ensure that the seeds of your begonias germinate, simply scatter them over the top of the potting mix and push them against the soil with your fingertips or a flat piece of cardboard.. Seeds should not be covered. It’s best if they’re placed pretty near, but try to make sure they’re distributed equally throughout the soil. Even though the seedlings will need to be separated, this is not an issue because you’ll have to do it anyhow when they’re grown up.

To ensure that the newly planted seeds don’t float away when I start begonias from seed, I use a mister rather than a hose nozzle to water them in.

With a sheet of clear plastic or a humidity dome on top of the seeding tray, set the tray in a location where it is exposed to light for 14-18 hours a day. To speed up and promote germination, place heat mats under the seed trays. Don’t give up on your begonias even if it looks like it’s taking forever to germinate, since certain kinds might take weeks or even months to sprout. The seed flats should not dry out, so if required, use a mister or spray bottle to keep them moist. As soon as the seeds begin to sprout, remove the plastic or humidity dome. As the plants become bigger, raise the lights.

When to Transplant Begonias Started From Seed

Transplant your begonia seedlings as soon as they have their first genuine leaves. Once the plants have been lifted out of their trays, use your fingers to carefully separate them. Replant the begonia seedlings into new sterile potting soil in nursery 4 packs or small plastic pots.

The pots or nursery packs should be kept well watered and the grow lights should be turned on for 14 to 18 hours every day. Begin bringing your begonias outside for a few hours each day once the threat of frost has passed. Over the course of two to three weeks, gradually increase the amount of time they spend outside until they are outside all the time. Once your begonias are firmly planted outside, you won’t have to worry as much about transplant shock or sunburn because of the hardening off process.

Which Begonias Should You Start From Seed?

Begonias can be grown from seed in a variety of ways. Although some species, such as rex begonias, are simpler to grow from cuttings, the experience of seed starting is a great one. I recommend starting with wax begonias, Dragon wing begonias, Angel wing begonias, cascading begonias, or tuberous begonias if you’re just getting started with begonia seed starting.

Begonia Devil's Delight Mixed F1 Plants From D.T. Brown Flower Plants

How To Grow Begonias From Seed Easily


When the begonia flowers begin to dry, look for seed pods like you would for calibrachoa. A piece of paper is all you need to harvest the pods before they break apart. If you do it this way, you can funnel the seeds into a container by folding the paper into a funnel.

Allow the seeds to dry for a week before separating the chaff from the seeds using two sheets of paper. If you don’t already have plants from which to collect seeds, there are a number of trustworthy online resources you can turn to. If you’re already a member of the American Begonia Society, they encourage using the seed fund.


Seeds are a practical method of acquiring new begonia varieties. However, you should wait until March to begin seeding because the seedlings will focus on tuber production if they start too early. A greenhouse can help you prevent this loss in productivity by ensuring that the climate and light conditions are ideal for their growth.

Remember to use seedling trays that are clean and new when planting begonia seeds. Use sterile seed-starting soil and disinfect the trays prior to planting to avoid fungal illnesses. However, a soilless mix recommended by the University of Vermont can be used for indoor begonia growing.

When you sow the seeds over the medium, don’t cover them with soil and leave some room between each one. The tray should be covered instead with a clear plastic sheet to ensure cleanliness and humidity. Begonias have a slow development rate, thus they might take anywhere from weeks to months to germinate, depending on the type.

The germination time ranged from five days for some gardeners to many months for others.


Using a growing light, such as a fluorescent lamp, will also be simple in the greenhouse. The American Begonia Society emphasizes bright light as a requirement to create healthy seedlings for transplanting and successful maturity. The recommendation for light is to have them on for 14 hours at a distance of 6 inches from the container’s top.

Using a growing light, such as a fluorescent lamp, will also be simple in the greenhouse. The American Begonia Society emphasizes bright light as a requirement to create healthy seedlings for transplanting and successful maturity. The recommendation for light is to have them on for 14 hours at a distance of 6 inches from the container’s top.

It will also be simple to employ a growing light such as fluorescent lamps in the greenhouse to encourage robust growth. In order to produce healthy seedlings for transplantation and successful maturity, the American Begonia Society stresses the importance of bright light. The advice for light is to have them on for 14 hours at a distance of 6 inches from the container’s top.

Begonia Plants - F1 Devils Delight Mixed | Dobies

Common Problems In Growing Begonias From Seed

Growing light, such as fluorescent lamps, can also be used in a greenhouse to encourage healthy growth. The American Begonia Society stresses the importance of strong light in the development of healthy seedlings that may be transplanted and grow into mature plants. 14 hours of continuous lighting at a distance of 6 inches from container’s top is recommended.


Beginner gardeners will benefit greatly from having begonias as part of their landscape. However, if you want to cultivate a variety of begonias, you’ll need to learn how to start begonias from seed. Prior to transplanting, proper preparation, planting, and upkeep can help assure a long and fruitful life for your plants.

A sterile seed-starting tray and seed-starting potting soil should be used to germinate the seeds. You can also grow your begonias in a greenhouse, where you can control the temperature and light levels. After the risk of frost has passed, you can gradually harden your seedlings before planting them in the garden.

There are several typical difficulties that can be avoided if effective management techniques are followed. Keep an eye on your begonias’ conditions and make sure you’re adhering to their ideal growing conditions.