Fort Bend Lifestyles & Homes November 2009
Shade-loving, big-blossomed tuberous begonias have a reputation for being
difficult characters in the garden. True, they
’re particular about how they’re treated. But, it’s also true that it doesn’t take much to keep begonias happy.
Once you understand their needs, growing begonias becomes easy and so worth any
small effort. Why? For gardeners with shady gardens, begonias offer something
—big color in dim light from flamboyant flowers that bloom non-stop mid-summer
Following are tips from the Netherlands Flower Bulb Information Center in Danby,
www.bulb.com, that will help any gardener “get” begonias.
Begonia tubers are available in early spring from garden retailers and
mail-order firms. In late spring and summer, potted nursery begonias are
available from garden retailers to plant
“as is” into the garden or containers.
Begonias are tender summer bulbs, very susceptible to frost. Don’t plant them out in the garden until the threat of frost has passed. Generally,
they take 12 to 15 weeks to bloom and then bloom and bloom, till the season
ends. For earlier bloom, start tubers indoors in pots in late winter or early
—about six weeks prior to the last usual frost date in your area.
Begonias love soil that drains well and shaded locations out of the wind. They
’t like full sunlight. Beyond these basics, three other conditions that can influence begonias are day
heat, night heat and humidity.
Ideally, begonias perform at their best where:
•day time temperatures are warm, up to 90°F
•night time temperatures are cool, around 55° to 60°F (12-15°C)
•average humidity is 69 percent or above (insufficient summer humidity is rarely
an issue in North America!) .
Where conditions veer from ideal, adapt
growing conditions slightly if you can. For instance, where too hot or wet, simply grow begonias in full shade or
Containers make it easier to control soil conditions and can be positioned to
minimize exposure to sun, heat and wind.
Start Tubers Indoors for Earlier Bloom
•Select begonia tubers that are firm to the touch.
•When possible, start begonia tubers indoors about six weeks before the local
planting date, when the threat of night frosts is past.
•Choose clean containers at least 2 to 3 inches deep with a drainage hole. Use a
commercial potting soil mixed with peat moss and sand, so soil stays moist but
•Place tubers in the soil mix with their convex (rounded out) side pressed gently
onto the surface of the soil. Cover with about one-half inch of soil.
•A warm, humid setting is optimal for promoting growth. Keep soil moist, but not
wet. Never let soil dry out completely.
•When shoots reach 6 to 8 inches tall, transplant to the garden or outdoor
containers. By this time the threat of frost should be past.
Plant Outdoors After Threat
of Frost Has Passed
•Best Spots: Plant tuberous begonias in well-drained, moisture-retentive soil
with a high humus content. Space plants one per square foot.
•Keep in mind: Begonias do not like hot sun. In warm climates, place plants in
beds that receive filtered, indirect sunlight. Keep away from direct sunlight,
midday heat and out of the wind. In cooler climates, direct morning and late
afternoon sun are okay, but avoid windy areas. Wind can dry out the plants.
Hanging baskets are especially susceptible to being dried out in a windy
•At Stake: Most upright-flowering plants will need staking.
•Sized Right: Depending on the size of the plant, an 8-inch pot is plenty big for
one plant. Three begonias fit nicely into a 15-inch pot.
•Moist Not Soggy: Keep soil moist, but don’t over water. Water the soil only and not the plant. A light application of
houseplant fertilizer is helpful, for optimal performance, about once a month.
•Friendly Pinches: For sturdier plants, pinch off extra or too long stems when the plants are
developing. Keep the strongest three stems and nip off any others. For fewer
but bigger flowers, pinch off early developing flowers, until the plant reaches
•Stopped Cold: In fall when night frosts hit, begonia season is over. Either bid
begonias adieu as annuals or, prior to a killing frost, lift the tubers for
over-winter storage. After letting the tubers dry off for several days, layer
them in peat in a cool dry place, 45
° to 50° F In spring, replant plump, healthy tubers for another season of bloom.
“For gardeners with shady gardens, begonias offer
something irresistible — big color in dim light. ...”
Begonia’s Bad Girl Image Undeserved
Expert tips for easy growing
Fort Bend Publishing Group 2008
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