A wealth of horticultural information makes the rounds in Round Robin letters every year. Even though begonia fans live in areas from coast to coast, in a variety of climates, certain cultural problems are Common to all.
These notes, gleaned from Robin’s correspondence, are rich in helpful hints for all who grow begonias.
Watering Problem
One of the most important problems is watering. A New York member who keeps her house at 65° degrees Fahrenheit says her begonias rot and die.
Since plants grown at that temperature need less moisture than those grown at 70° degrees Fahrenheit, this sounds like the result of overwatering.
A Kansas City member finds that chlorinated city water kills her begonias. This is a warning for others to find out about their water supply.
Use rainwater if possible, but if this cannot be obtained, let water drawn from the tap stand in the open air for 24 hours so most of the chlorine will evaporate.
One of our California members saves water when she defrosts her refrigerator since no rain falls in her area from April to October.
A California Robinette uses the Rose-croft solution the late Alfred D. Robinson recommended to soften hard water. He used 1/2 ounce of super-saturated alum to one gallon of water – a formula originally worked out for azalea or rhododendron seedlings.
Through trial and error, robin members have also found that fibrous begonias need more water than rex begonias, and rex Lavender Glow needs less water than most other rexes, which like moisture on their leaves but resent soggy root conditions.
House-grown begonias approve of a spray of tepid water two or three times a week. Take care not to let the sun touch the wet leaves, for they’ll blister. Never use cold water on begonias in winter. This chills the plant and causes the leaves to drop.
Favorite Soil Mixture
Almost everyone who has grown houseplants for several years has a favorite soil mixture. Begonia fanciers are no exception.
A western New York Robin member uses wood soil which contains enough coarse sand to require nothing more than the addition of garden soil.
She uses two parts wood soil to one part garden soil for fibrous. rex and rhizomatous kinds. For semperflorens begonias, wood soil used alone increased the size and quantity of the blossoms.
With equal parts of wood and garden soil, the sizes of the plants were smaller, and with garden soil alone, it resulted in a still smaller plant.
When a top dressing of wood soil was added, the plant responded with better growth. This Robinette rated liquid cow manure as the best fertilizer.
Colorado Mixture
From a Colorado fan comes a word that a favorite soil mixture is a peat, leaf mold, and compost in equal parts with a dash of soot, manure, and superphosphate.
Florida Mixture
One of our Florida members mixes one bushel of sifted leaf mold, one bushel of peat moss, one old cow manure, one compost, and two quarts of bone meal.
For fertilizer, she uses a nutrient solution of yeast, bone meal, and 5-8-12. This does not develop toxicity in long usage as fertilizers do.
New Jersey Mixture
A letter from a New Jersey begonia addict tells of using soil from the bottom of the manure pit, wood soil, and garden loam in equal parts. Her fertilizer is liquid cow manure, and the site supplies fresh soil on hand to top-dress her plants in winter.
Connecticut Mixture
A Connecticut member who grows superlative plants says she has no hard and fast rule but mixes according to “feel,” using oak leaf mold, cow manure, and reasonably good garden loam with a dash of bonemeal, a little charcoal, and some soot.
Soot from chimneys connected with oil burners should not be used, as one member learned to his sorrow.
Oregon Mixture
Information from Oregon indicates that chimney soot from a wood-burning stove is beneficial in the potting soil. This member also mixes a handful of soot in a gallon of water and uses this on her seedlings once a week.
For mature plants, use one teaspoonful in a 4-inch pot, stir into the topsoil, and water in. Soot stimulates growth, improves the color of foliage and flowers, and repels soil-dwelling pests. For flower beds, use one pound for every 30 square feet.
Maine Mixture
A Maine member, who has a small greenhouse, mixes one part soil, one part leaf mold, half part sand, and a half part old cow manure, plus a little bone meal. Her favorite fertilizer is Electra, a New England product like the English Clay’s.
She also uses 4-12-4 with success. An Oregon correspondent has no oak leaf mold in her vicinity, so she makes hers from the leaves of cottonwood, wild cherry, buckbrush, and locust trees.
Nebraska Mixture
One of our Nebraska members, who grows unusually fine rexes, uses 1/4 of each loam, manure, sand, peat, or leaf mold, adding a little fish meal.
Growers who live in or near the country can usually get all these materials without much difficulty, but an apartment dweller in Washington, D.C., must buy her leaf mold at a drugstore! For sand, she uses French bird gravel.
Difficulties In Florida
Since begonias are chiefly tropical plants, one would expect them to grow luxuriantly in Florida on the edge of the tropics. Yet Florida members have as many difficulties as the rest of us, although they may differ. The heavy rains damage some kinds of glass houses that are needed for them.
One of our Florida members says the Woodruff hybrids do not grow well in her locality. But Coral Imperatives bears more than 50 flower stalks of charming coral-Rushed buds and pinkish-white flowers.
The female flowers have green seed pods and are so much like Begonia speculata that she wonders whether it is a speculata child. B. New Hampshire has lost its variegated leaves in her garden and is now just a semperflorens.
Another Florida member says most of her begonias are grown outdoors all year round, although her locality has some freezing weather. Then the more tender plants, especially the rex begonias, must be brought inside.
The semperflorens live all year outdoors, protected with moss from the trees when a freeze threatens. They grow and bloom well on the north side of the house—some planted in garden soil, some in boxes: Some are planted in leaf mold, others in ordinary soil with top dressings of Vigoro.
This grower also reports that the double semperflorens will not stand crowding and do not like the indoors. Some were brought in for a couple of weeks last winter but nearly died.
They dropped their leaves and lost vigor. The heating system did not cause this, for there was none. This robin member uses water from the springs when there is no rain.
A Robinette in the southern part of the state has a 15-foot plant of Corallina de Lucerna growing in her yard.
She successfully uses a 3-inch mulch of sawdust, but some north Florida members find sawdust kills their plants because the local supply is from pine trees and rain leaches out the raw turpentine.
Begonia Popenoei In Florida
Another Florida member has two plants, and both are labeled B. Popenoei. One is rhizomatous and has large light green leaves and seed capsules with an extended wing.
The flowers do not compare in beauty with those of the other plant with an erect rootstalk, large handsome white flowers, and a similar seed capsule.
The leaves of both plants have serrated edges and are not densely hairy, as given in the description of B. Popenoei.
This fancier doubts whether either of these is the true B. Popenoei, formerly called “Florida species.” although it is a native of Honduras where it was. found by Paul Standley in 1927.
Rhizomatous Begonias
All the rhizomatous begonias do well in this member’s Florida garden. She uses B. nigricans, B. fuscomaculata, and B. nelumbiifolia in long rows in the garden. B. Washington Street was 3′ feet high and in full bloom in early spring after blooming most of the winter.
It is planted in a 6-inch shallow pan. B. Templin is colored wonderfully – a cream, pink and green symphony. This, too, is planted in orchid fiber in a shallow pan.
The Woodruff hybrid, Tea Rose begonia, has been one of her most delightful plants, full of fragrant blossoms since it was a tiny plant. This is a different experience with Woodriff hybrids than another Florida Robinette reported.
Begonia Bessie Buxton
A cutting of B. Bessie Buxton, which this member received last fall, started blooming within two months and quickly grew to 18” inches.
It is far better, she thinks, than B. feasti which is supposed to be a hybrid. It has finer flowers and is more floriferous over longer periods. Many northern growers report difficulty with this plant.
I have a report on two interesting begonias which other fans might like to grow. Begonia rotundifolia is a true miniature about 6″ inches high with little rhizomes only 1 inch in diameter.
From these rhizomes, which hang gracefully over the edge of the pot, spring the round. bright green leaves with tiny, scalloped edges. They are from 1” to 2” inches in diameter, borne on 4- to 5-inch bright red stems.
Some leaves are quite flat, others slightly spiraled with an overlapping lobe, and occasionally, there is a tiny auxiliary leaf at the sinus.
The plant blooms freely in early fall with white, rarely pink. 4-petalled flowers with narrowly oblong golden stamens, borne high above the leaves on foot-long red stems.
This begonia was among the first six discovered nearly 200 years ago. Later it returned to obscurity and was lost to the world for nearly two centuries until 1903 when Dr. N. L. Britton and his assistant, Norman Taylor, found it growing on steep clay banks on Mt. Maleuvre, Haiti, at 1640 feet altitude.
Begonia Heracleifolia
There is also a new, as yet unnamed, variety of Begonia heracleifolia found in Mexico by Thomas MacDougall in 1943. However, it is creeping into commerce.
The light yellow-green seven-pointed leaves are borne on foot-long stems, deeply eight-channeled.
The stems have scattered silky white hairs, and at the junction of leaf and stem, there is a collar of long, greenish-white hairs. On the upper surface of the leaf, the heavy veins meet in a white star at the sinus.
Most noticeable about this begonia is the young leaves with curving points, giving a wheel shape or whirling circle.
Like most rhizomatous begonias, it is a good grower, even under hard house conditions.
Like the others, it blooms in the early spring from February on, bearing tall sprays of small pink flowers with bright green ovaries for a month or more. They last for weeks and set seeds freely.
So, from the experiences of many Round Robin members all over the country, we gain valuable information to help us grow our plants more successfully and to do gardening in all its phases, paying even richer rewards than ever before.
44659 by Bessie R. Buxton