Today we are discussing the Double Begonia or Begonia Semperflorens, the famous annual flower. It is an ideal plant for patio planters, garden beds, and window boxes for flower lovers.
It is similar to the single Begonia, but the showy blossoms for this variety have double sets of petals.
Double Begonia is a low-growing annual with other common names as wax begonia and bedding begonia.
To help your Double Begonia grow well and bloom prolifically, provide warm temperatures, little watering, and well-draining soil. They are easily grown inside or outside with low maintenance.
According to the University of Florida, Begonias have over 1300 species that symbolize individuality and uniqueness. Well known for decorative flowers and leaves, this ornamental plant is named after Michel Begon, who was French governor.
Double Begonia belongs to Begoniaceae, which is one of the largest flowering plant family. This plant with vibrant blooms and lush green foliage looks good in any modern or traditional planting scheme. It will attract wildlife like bees, hummingbirds, and butterflies in your garden.
Double Begonia is a stunning flowering plant that is simple to grow, and we have prepared a complete care guide to help it thrive as a container or garden plant.
Double Begonia Care
Table of Contents
Double Begonia Plant Care Instructions
Soil
Choosing the right potting mixture is the key to successful Begonia growth. Double Begonia requires well-draining potting soil. Use fertile soil with lots of leaf mold or amend the soil by adding organic matter like compost or peat moss.
You can also use an African violet potting mix for Double Begonia. But make sure the potting medium is slightly acidic.
If you want to keep the plant outdoors, first plant it indoors in late winter, so it has enough time to mature before transplanting them outside in warm weather. This will also ensure that your Begonia blooms as soon as you plant it in the garden bed. Hardening off the Double Begonia will be discussed later in this article.
Double begonias are hardy in USDA zones 8-10 and considered annuals in USDA zones 3-7.
Watering
After planting, water the young plant frequently for the first 2 weeks to keep the soil slightly damp. Later on, in the growing season, water the plant only when the soil is dry. Never let the soil get waterlogged or soggy.
Examine the topsoil before water applications; if its dry water the plant, if it’s still wet, you can skip watering. Water the Double Begonia until the soil is soaked and water runs through the drainage holes. I would recommend watering at the base to keep the foliage dry and prevent leaf spot or fungal diseases.
Double Begonia needs regular watering for healthy growth. If you live in a dry climate, supplement your Begonia plant with a fine mist via the sprinkler for 15 minutes in the afternoon and sufficient bottom watering when the soil is dry.
The quickest way to kill any begonia plant is overwatering since it causes root rot. For this reason, I always allow the soil to dry out between watering and water my plants over a sink or bowl to allow the excess water to drain out.
Young Begonia plants are highly susceptible to root rot, so it is important not to let the soil sit in water else water will accumulate in the hollow part of tubers.
This Begonia species is not drought tolerant, but in cooler temperatures or rainy seasons, it can withstand for a longer time without water.
Planting
The best time to plant them is the start of May through August for U.S.D.A. hardiness zone 8. In the U.S.D.A. zone 9, you can plant them any time between April to October. In U.S.D.A. zone 10, you can plant early February.
Tubers: When planting young tubers of Double Begonia, place the hollow side up and keep 1-inch spacing. Place them in a shallow pot in a moist potting mixture. Now place the tray in a dark area and water regularly to keep the mixture moist.
The tubers will sprout in about 4 weeks. Roots will start developing on the bottom, sides, and top of the tuber, whereas stems will begin growing from the top. You can move Double Begonias to a bright location when they are around 1 inch tall.
Replant the tubers in their permanent containers and continue caring for it as a houseplant or transplant it outdoor. But only take it outdoor if there is no threat of frost.
Mostly small tubers produce small begonia plants, and large ones produce large plants. The flower size entirely depends on the number of stems on each tuber.
Seeds: Although this is rarely practiced, you can start your Double Begonia from seeds also. The seeds should be planted in December or January for summer blooms. Fill a pot with a fine-textured potting mixture and place the seeds on the surface. Now cover the seeds with sphagnum moss.
Always moisten the mixture before sowing the seeds. Cover the pot will plastic wrap or glass to lock moisture.
Germination will start in about 10 days. If the temperature is lower than 21 degrees Celsius, it can take up to 3 weeks. You can remove the plastic or glass covering two days after germination. You should thin the seedlings to 1 inch apart, and if they are overcrowded, transplant them to a larger container.
Light
Double Begonia grows well in partial sun and shade. Generally, a location with morning sun and afternoon shade is ideal. Always protect the plant from hot afternoon sun else; the foliage will scorch.
The best location would be the north or east-facing window. If your indoor plant experiences any sunburns, move it slightly away from the window. For outdoors, choose a location beneath a tree or a covered patio to diffuse direct sunlight.
Avoid keeping the plant in a densely shaded spot else this flowering Begonia tends to produce more leaves than blooms. Grow lights are an excellent alternative for natural sunlight for growing the Double Begonia indoors in winter or areas with low light.
Temperature
They really enjoy warm and humid temperatures. The optimum temperature range for the Double Begonia is from 18-22 degrees Celsius (65-72°F). Remember that begonias are highly frost tender, and any temperatures below 10 degrees Celsius (50 oF) can damage or kill the plant.
Double Begonia can often tolerate high temperatures with protection from harsh sunlight.
Humidity
This tropical plant will grow well in medium to high humidity conditions, between 50 – 80%. You can boost the indoor humidity level by setting the pot in a pebble tray or saucer. Fill it with water and make sure the pot is sitting on pebbles, not in water.
Or you can use a humidifier to improve the indoor humidity. Do not place the plant near the radiator or heat sources.
Fertilizer
They are heavy feeders, so you have to fertilize your Double Begonia right after planting. To enjoy abundant blooms, apply 10-10-10 liquid fertilizer diluted at a ratio 1:3 when you first plant or transplant the Double begonia.
Later fertilize your plant once a month or every three weeks during active growth season using a balanced liquid fertilizer.
To fertilize the Double Begonia plant, I would suggest pouring the solution around the base instead of spraying it directly on the plant. You should avoid applying fertilizer to the foliage because the leaves and stems can be damaged by direct contact with strong fertilizers. Over-fertilizing can scorch the leaves leading to fertilizer burns.
Repotting
Potted begonias should be kept slightly root-bound. So repot only when necessary in the spring season before the plant is moved outdoors in active growth. Avoid using a large pot because it will hold extra water and hinder plant growth.
Pruning
Double Begonia is the most famous bedding plant with low pruning requirements. It won’t grow heavily or overgrow its pot frequently.
Prune off the Double Begonia by removing any faded or dead blooms. Trimming the deadheads will save the plant’s energy that will be otherwise wasted in reviving them. Just pinch the stems once a month to remove dead parts and encourage growth. This will result in a busier plant.
If your Double begonia plant is being leggy, i.e., growing towards the light, you can prune and force the plant to grow from a certain part.
Propagation
To expand your Double Begonia garden, you can either buy the tubers from a local plant nursery in late spring or grow them from seeds. But the most reasonable method is to propagate and grow your own collection.
Double Begonia can be propagated through cuttings, division or seeds. But Propagation via root or leaf cuttings are the most successful methods for this species, so we will be discussing them in this article.
Stem cuttings
- Before taking the stem cuttings, prepare the Forsythe pot. Take a 2 or 3 inches unglazed clay pot with a drainage hole. Now fill another 10-inch plastic pot with vermiculite
- Place the clay pot inside the plastic one and push it in the vermiculite.
- Moisten the vermiculite and fill the small clay pot with water. Take 3 inches long stem cuttings and insert them in the vermiculite.
- Put this setup in a plastic bag and seal the top to create a humid environment. For right propagation place the Forsythe pot in bright indirect light with warm temperature
- The clay pot will act as a water reservoir, so you don’t have to water the cuttings just fill this pot with water.
- It would be best if you open the plastic bag every few days to help it accustom to the natural humidity.
- After 2 or 3 weeks, the cuttings will be well-rooted. By the end of September, small tubers would have formed.
- Now you can transplant them or harden them off as described below before taking them outdoors.
Leaf tip cuttings
- Take 3 to 4 inches cuttings from a healthy Double Begonia plant with at least two nodes. Do not include any blooms in the cutting.
- Remove any leaves at the lower part. Pinch the top of the cutting at leaf joint so the cutting will have new leave growth on the top.
- Now place them 2 inches deep in a moist rooting medium in a pot. Place the pot in a warm and semi-shaded area until new growth starts.
- Water the cutting from below by putting water in the pan or saucer and let the water reach the cutting by capillary action.
- Once the cutting has developed roots, you can over winterize it to replant in the garden next summer season.
Blooms
Double Begonia bloom from early spring through the first frost. It takes about 12 to 14 weeks for a Double Begonia to start blooming after its planted.
You have so many colors to choose from since it comes in a variety of colors ranging from pink, yellow, white, and scarlet. You can either grow a single colored Double Begonia or pair your favorite colors together. Some of the varieties are listed below:
Bouton de Rose Double Begonia – This is a beautiful Double Begonia with delicate white and bright pink rose-shaped flowers. The petals are white, edged in shades of bright pink and true red, giving an instant pop of color.
Orange Double Begonia – This one has warm colored orange blooms. The ruffled blooms complement other pink and white flowering plants in your summer garden and can reach about 15 cm in diameter.
Pink Double Begonia – As the name suggests, this variety has pink blooms. The large blooms have a luscious texture and resemble camellia flowers. This is a charming addition to any shady corner in your house or outdoor lawn. The foliage color varies in shades of dark green, dark bronze, and black.
Red Double Begonia– This one has vivid red or scarlet petals that create a magnificent red display in any indoor or outdoor setting. The multi-layered flowers can get 10-20cm in size, and the flower heads sit on a bed of ruffled foliage.
White Double Begonia – This one is a classic, suitable for any location. The pure white flower heads on this variety also resemble camellias. Together the creased white petals and the dark green foliage create a pleasing look.
Yellow double Begonia – It is a camellia-flowered beauty that offers vibrant begonia blooms in lush a buttery yellow shade. These bring a splash of sunshine in any landscape or container garden.
Growth
Double Begonias grow to a height of 40cm, which makes them well-suited for container gardening. They are well known for extra lush foliage and extra-large flower growth. The flowers usually reach a diameter of around 15cm (6 inches) when fully opened.
Hardening off Double Begonia
I would highly suggest hardening off your indoor double Begonia about two weeks before the last frost date. This will help them accustom to outdoor conditions. You have to move the plant outdoors to a shaded area on a warm day.
Bring it indoors before temperatures cool off at night. Repeat this process for the next 2 to 3 days and gradually start placing it in a brighter location.
Once the weather is suitable, the soil is warm, and there is no risk of frost damage, you can transplant the Double Begonia to a hanging basket or outdoor garden. Choose a permanent spot for it on the deck or patio.
Overwintering double begonia
You can overwinter your Begonia as an indoor houseplant during cold months. This is done to guard them against frost damage. Dig the plant from garden soil and pot it in a container. Keep the plant near a window to allow it to have bright filtered sunlight in winter months.
An extra care step is that you have to watch out your indoor plant against fungus problems. This is rarely an issue for outdoor begonias because the natural wind circulates air through the leaves. I recommend spraying the plant with a fungicide when brought indoors. Use the bottom watering method and keep the soil of overwintering begonias damp.
Overwintering will also force blooms on the begonia plant. Tuberous begonias are considered difficult to overwinter because the tubers may rot or die if the temperature is too warm or too cold.
Storing Double Begonia
Double Begonia will enter a dormant period in winter months regardless of how they are grown (in greenhouse or outdoor). During dormancy, the tubers should be stored indoors because outdoors, they will be killed by cold weather or frost. Below are the steps to properly store the tubers:
- Minimize watering and stop fertilizing the plant at the end of August. You can also remove any flower buds to encourage dormancy and save the plant’s energy.
- Remove the plant from the soil right after the first frost or when the leaves start yellowing and apply a garden fungicide.
- Trim the stems to 5 inches and allow the tuber to dry at an indoor temperature in a shaded place out of direct light for 1 week.
- Now pull off any stems or roots from the tubers and remove the soil around it. Do not wash the tuber.
- Place the Begonia tuber in a plastic bag with peat moss or vermiculite. To protect from powdery mildew, dust them with sulfur powder and store each tuber separately in paper bags or wrap in newspaper.
- Store it them at a cool and dry place with temperature ranging from 40 to 50o You can also store in a bare refrigerator with other bulbs or tubers.
- Inspect the tubers frequently for rot or withering. Discard the damaged tubers because they will not have healthy growth in the next season.
Common Problem for Double begonias
Powdery mildew
A fungal infection that spreads fast between Begonia species. The top surface of the leaves will have white, powdery, and thread-like growth. Powdery mildew feeds on the leaf cells leading to poor growth, but it will not kill the plant.
Plant your Double Begonia in a location with good air circulation to avoid this infection. Transfer your plant to an area with stable humidity and high temperature to kill the fungus.
Mealybugs
These pests colonize the Double Begonia stems or leaves to feed on the plant sap. Large infections can slow down the growth rate. The honeydew secreted by the mealybugs blocks the pores and interferes with photosynthesis. Hose the plant with a strong spray of water to wash off the pests and their honeydew.
You can also use chemical controls like spraying the top and bottom of the leaves with insecticidal soap.
Begonia Pythium rot
It’s a fungal disease that represents Begonia stem and root rot. Symptoms include rotting stems above soil level, darkened foliage, and rotting roots. Once infected, the plant cannot be treated; the only option is to dispose of the plant.
You can prevent this disease by sterilizing your potting soil, pots, and tools. Do not sow the seeds very deep and avoid overwatering the plant. Maintain good air circulation around the plant.
Tips for growing Double Begonias
The big, bold blooms make Double begonias an absolute favorite in any summer container garden. You can also enjoy plenty of blooms with the following tips:
- Start the plant indoors in late February for early blooms in summer.
- Do not plant the Double Begonias in containers on hot surfaces such as asphalt or concrete.
- Avoid planting or placing the Double Begonia in areas with strong winds. The weak stems can be damaged by strong winds.
- Soak the tubers in water for few hours prior to planting. This will rehydrate them and help them grow.
Frequently asked questions about Double Begonia
Why are the flower buds dropping before blooming?
Too much or too little watering can cause the Double Begonia to drop the flower buds even before they bloom. Giving the right amount of water is essential for blooming, so check your plant every day for watering.
Does Double Begonia grow back every year?
This begonia species is an annual houseplant. So it won’t grow back each year, you’ll have to replant them in spring.
Does this plant need deadheading?
Double Begonia is a self-cleaning plant, so it does not require deadheading. It will naturally drop off any spent flowers. But if you want to clean your plant faster to produce more flowers, you can deadhead.
Is Double Begonia pet friendly?
No, because begonias are toxic for pets. Although they are non-toxic for humans, they can still cause irritation and allergies.
Conclusion
Double Begonias with their brilliant colors and rose-like blooms are a must-have for flower growers. You can enjoy the vibrant blooms from late spring to fall with proper care. With fluffy blooms, this variety looks beautiful in pots and hanging baskets. It can be grown as an annual, or you can overwinter the tubers indoors.
I suggest you have a look at my favorite Begonia, Begonia maculata next. Begonia maculata care is easy and the plant looks stunning with its white dots on the leaves as well as the red undersides.