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Begonias

Begonias do better in warm climates.

The Temperature Range for Growing Begonias

Begonia, a genus of tropical and subtropical plants, grow as perennials in warm climates and annuals elsewhere. Some species, such as Begonia grandis, or "hardy" begonia, grow in USDA zones 6 through 9. Begonias are best suited to USDA zones 9 (with protection) through 11, where minimum average temperatures range from 25 degrees F to 40 degrees F and above.

Begonia, a genus of tropical and subtropical plants, grow as perennials in warm climates and annuals elsewhere. Some species, such as Begonia grandis, or “hardy” begonia, grow in USDA zones 6 through 9. Begonias are best suited to USDA zones 9 (with protection) through 11, where minimum average temperatures range from 25 degrees F to 40 degrees F and above.

Care of a Beefsteak Begonia

Grow the beefsteak begonia in a potting mix consisting of equal parts of potting soil, vermiculite and peat moss.

Keep the beefsteak begonia in an area that receives indirect sunlight or bright shade and remains above 55 degrees Fahrenheit.

Water the begonia at the soil with room-temperature water. Give it enough water so that it drains from the bottom of the pot. Allow the soil to dry out almost completely before watering again. If the foliage begins to wilt, water the plant. Beefsteak is susceptible to root rot so it is important not to overwater.

Fertilize the beefsteak begonia with regular houseplant fertilizer. Dilute the fertilizer to one-fourth the strength listed on the label and apply it once a month, March to October.

How to Grow Rieger Begonia

Plant your begonia in an area that receives filtered sunlight or part shade. If grown inside, place your begonia in an east window. If the foliage turns copper, the plant is receiving too much light.

Water once a week when the top of the soil is dry. Water your plant at the soil line to avoid wetting the foliage, which can lead to powdery mildew. Rieger begonias can put up with less water than normal, but they will not survive having their roots constantly wet.

Fertilize once a month with a water-soluble 15-30-15 fertilizer. According to Michigan State University Extension, over-fertilization will cause blue green foliage that curls at the ends

Deadhead spent blooms, and pinch back long stems to keep the plant compact. If the entire plant gets too leggy, cut it back by half.

Bring your begonia inside around a week before the earliest frost date for your area. Reduce the amount of watering. Let the plant rest for two weeks without water, then prune it and begin watering once more. Return the plant to the garden in the spring after the final frost date.

How to Prune a Begonia

Prune overgrown stems back to maintain the overall shape of begonias. Pinch the fleshy stems at the appropriate length any time you notice the plant needs shaping. Avoid simply cutting off the top as this gives the plant and unnatural appearance. Regular trimming encourages lush growth and creates an attractive plant.

Cut begonias grown outside back to 4 inches when moved inside to revitalize the plant and reduce stress associated with a change in growing conditions. Save cuttings and root in a jar or vase of water to produce new plants. Pot when the cuttings have developed healthy roots.

Pinch out the center leaves on begonias once a month to encourage a compact plant. This forces new foliage to form along the stem and around the base of the plant. Pinching can be reduced once the plant appears full and shows lush growth.

How to Trim Begonias

Cut back begonias by trimming 3 to 4 inches from terminal ends if the plant becomes overgrown or blooming decreases. Regrowth occurs quickly and a flush of new blooms follows.

Trim stray stems that extend beyond the shape of the plant to maintain the overall shape. Wax begonias, often used a bedding plants or in window boxes, should be maintained in a rounded mound. Use clippers or snap the stems by hand, taking care not to damage existing foliage.

Pinch back the terminal ends of begonias when they are 4 to 6 inches high to force new growth to appear along the stems. Repeat once a week until the plant develops compact foliage. This increases both foliage and blooms.

How to Space Begonia Plants

Plant begonia tubers just under the surface of the soil with the bud--or eye--facing up.

Space multiple begonias 6 inches apart. Most begonias plants grow to be 10 to 12 inches high and planting them 6 inches apart gives them plenty of room to grow.

Alternatively, plant larger begonia plants 12 to 18 inches apart. Some varieties can grow to be 18 to 36 inches tall, such as the red begonia (dragon wing) and therefore need more space to grow.

How to Winterize Begonia

Reduce watering to once a week in late autumn to force begonias into dormancy. Cease fertilizing at this time and allow the foliage to die back naturally.

Dig up the begonias as the foliage begins to die back or after the first frost, whichever occurs first. Dig around the tubers in a circle to avoid cutting them, then lift them out of the loosened soil.

Cut the stems down to five inches with a sharp knife or garden shears. Lay the tubers on a layer of newspaper in a dry room away from direct sun for five to seven days.

Fill a perforated plastic bag with dry peat moss or vermiculite. Place the tubers inside without touching one another.

Place the bags in a cool, dark place with a temperature between 40 and 50 degrees Fahrenheit. Check the tubers every two weeks during storage for soft spots or other signs of rot, and discard any that are affected.

Begonias

Buy This Book

Begonias

by Mike Stevens

ISBN 1-55297-551-7
96 pages, 7 3/4 x 10 1/4
full-color photographs; Paperback.

Mike Stevens presents a complete and readable guide to one of the most popular flowering plant choices: begonias. The Begoniaceae has as many as 1,000 known and identified species plus countless hundreds of hybrids. This informative and practical guide for gardeners focuses on the popular tuberous begonias, and also includes:

  • history and key discoveries
  • culture of non-tuberous begonias
  • large-flowered tuberhybrida in containers year-round
  • basket begonias
  • fertilizers, soils, watering and propagation
  • creating your own hybrids
  • remedies for pests, diseases and disorders
  • 95 beautiful full color photographs

With dozens of the author's recommended species and hybrids plus nursery sources and a bibliography, Begonias is a solid reference work.

About the Author
Mike Stevens has a specialist's knowledge of begonias and is known worldwide as a knowledgeable and generous source of expert advice. His photographs are a pictorial record of his "beauties," many of which appear in this book in luminous full color.

Table of Contents

Introduction
1. History and Key Discoveries
2. Culture of Non-tuberous Begonias
3. Tuberous Begonias
4. Cultivation of Tuberous Begonias
5. Large-flowered Tuberhydrida in Containers through the Year
6. Basket Begonias
7. Begonias in the Garden
8. Pests, Diseases and Disorders
9. Fertilizers and Soils
10. Watering
11. Propagation
12. Creating Your Own Hybrids
Appendix 1: Exhibiting Your Plants
Appendix 2: Useful Addresses
Selected Bibliography
Index

Can You Winter Over Bonfire Begonia?

Bonfire begonias produce bright red blossoms.

Bonfire begonias (Begonia boliviensis ‘Bonfire') can be saved over the winter. In mild winter areas, leave the begonia tubers in the ground. In areas that experience freezing temperatures, remove the tubers from the ground and plant them in loose soil in a container. Store the container in a cool, dark place that is protected from freezing temperatures.

How to Harvest Begonia Seeds

Cut out the flower pods with a pair of sharp scissors. The flower pods are located in the center of the bloom.

Place the flower pods in a large envelope for one to two weeks, or until dry. Make sure the envelope is large enough that it doesn't flatten the pods.

Remove the pods once they are dry, and put them on a paper plate.

Pull the pods apart to remove the seeds. The seeds are tiny, cylindrical and a shade of red. Separate the seeds from all other plant material.

Place the seeds in a small paper envelope. Label the envelope with the date and the type of seeds. Store them in a cool, dry place until you are ready to use them.

How to Care for Begonias Indoors

Place your begonia plants in a window or patio where they will receive several hours of filtered sunlight each day. Begonias will tolerate direct sun if kept cool, but the leaves will look healthier if kept in filtered light.

Keep the soil in your begonia containers moist. Make sure the container has good drainage, as the roots of the begonia do not tolerate sitting in water-logged soil.

Cover the soil in your begonia containers with a layer of mulch to help maintain adequate soil moisture.

Mist your begonia plants daily using a fine setting on a spray bottle. This is especially important if you live in a dry climate, as begonias thrive in humidity.

Fertilize your begonia plants once a month with a liquid fertilizer diluted to quarter strength.

How to Mound Annual Begonias

Select one or more the many wax begonias from the nursery. Often sold in flats of six or more, planting several plants together in one location creates a blanket of color.

Plant begonias in a location that receive bright filtered light, but no direct sunlight. They tolerate morning light, but suffer under the hot sun. Some varieties thrive in shaded areas where many other plants struggle.

Pinch out the center leaves on the terminal ends of branches to encourage the begonia to send out new foliage along the main stem and branch. Use your thumb and finger to pinch the leaves free of the stem. This forces dense compact growth that creates a mound of foliage.

Cease pinching when your begonia develops the shape you desire and allow it to begin blooming.

Trim or pinch back any stray branches that grow outside of the overall form of the plant to maintain a rounded mound. Typically, pinching is required every 3 to 4 weeks to maintain shape.