Question
I have gone through and read most of your answers to questions..Amazing knowledge you have. You recommended Begonia for container with shade and partial light to me. I can't find any info from you in your answers about begonias. They are lovely plants, but I have stayed away from them as they have not in the past been fast growers for me. What are your recommendations for begonias and what could I plant in the container with them? ( something tailing to make containers have a overflowing look as begonias do not hang over) Or maybe I am wrong. I am inexperienced with begonias but I am going to give them a try this summer. ( I live in Massachusetts) I appreciate your time and all of your wonderful knowledge on this subject...WOW!

Answer
Begonias are easy to grow and undemanding when it comes to light.  There are 3 kinds commonly sold by retailers.

'Wax Begonias' ('Begonia semperflorens' to botanists# are popular landscape plants.  After an al fresco Summer, these can be dug and potted for a Winter indoors, where they will brighten windowsills.

I have loved Wax Begonias since my college days, when I kept a collection in my dorm room.  You can choose from bronze or apple-green leaves.  Generally, they come with flower colors Apricot, Pink, or White.  The driveway that cuts across the lawn of my gray Craftsman style house is lined during Summer with the bronze-leaved Apricot variety; it has a Northern exposure, and they do well there.  For my house, the apricot and bronze colors are perfect. These are day-neutral Begonias that will bloom year round #'semperflorens' means 'always flowering'.

'Tuberous Begonias' (B. X tuberhybrida) need protection from the sun, or their leaves will scorch. They are larger than Wax Begonias, with big, beautiful, brightly colored flowers.  They can be difficult, but practice will solve that.  (No such thing as a Green Thumb.  I have killed hundreds of plants.)

Over-watering, over-fertilizing, over-lighting them will cause their buds to drop or leaves to shrivel.  Because Tuberous Begonias are long-day plants, they will not flower in the winter, no matter how nice you are to them or how much you practice, without substantial artificial lighting.

Third: Rieger Beonias (B. X hiemalis). A Rieger in bloom looks just like a Rosebush at the height of bloom.  These are  probably the trickiest of this group, 'facultative short-day plants' that flower in Winter, when days are short and temperatures are cool.  (The word 'hiemalis' means Winter-flowering.)

A fourth group, Angel Wing hybrids created in 1926 by a breeder in California (a cross of B. aconitifolia and B. coccinea), is primarily an indoor plant. But these can be striking focal points in the company of other Begonias outdoors.  They tend to grow quite large, their leaves being substantial, with great presence (like "wings").

Now for some color photos.

Although I would not buy anything from them these days, White Flower Farm still puts together some beautiful pictures of Begonias for sale.  Their Blackmore and Langdon strain of TUBEROUS BEGONIAS are the gold standard of this genus, and you'll see why:

www.whiteflowerfarm.com/40407-product.html
www.whiteflowerfarm.com/40352-product.html
www.whiteflowerfarm.com/40310-product.html

Connecticut's White Flower Farm apparently licenses the rights to grow and sell Blackmore and Langdon Company's Begonias in the U.S.  WFF has such a close working relationship with the B%26L, a 100-year-old British greenhouse specializing in Begonias and Delphiniums, that they named 2 of their horses Blackmore and Langdon.  Here's more on the B%26L website in red, white and yellow:

www.blackmore-langdon.com/detail.asp?id=W00000000024
www.blackmore-langdon.com/detail.asp?id=W00000000028
www.blackmore-langdon.com/detail.asp?id=W00000000022

Given the prices WFF is charging for the precious flowers, it might be cheaper to go to England on vacation and come back with a few from the growers.  I'm sorry, but $48 is highway robbery for a Begonia.

WAX BEGONIAS are far more humble, and although WFF sells a red-flowered bronze-leaved version for who-knows-how-much, you can find them at your local garden center for a song:

www.whiteflowerfarm.com/70547-product.html

You can also find them at Logees, the Danielson, Connecticut greenhouse specialists who sell some very pretty hybrids for $9 to $15/plant:

www.logees.com/prodinfo.asp?number=B3014-2
www.logees.com/prodinfo.asp?number=B3022-2

Cornell Cooperative Extension also posts a pretty photo of a Wax Begonia:

www.ccenassau.org/hort/fact_sheets/a129_begonias.pdf

Bronze leaved varieties are more tolerant of full sun.  This does not apply to ALL Begonias.

For that shady porch (like mine), where there is never enough sun for baskets of Geraniums or Pansies, a few baskets of RIEGER BEGONIAS will glow all Summer. This treatment is illustrated on their website by Klems Greenhouse, a major wholesaler:

klemsgreenhouse.com/gallery.aspx

Problem Begonias?  Well, no one's perfect.  Begonias have their Achilles heels like any other palnt. As a group, they are hyper-sensitive about Ethylene gas.  That's the invisible chemical released by things like ripening fruit OR spent flowers.  Diligent removal of Begonia blooms past their prime will keep more coming.  The plants look prettier, too.

Outdoors, those at ground level must be protected from Slugs and Snails.  If you have a lot of these nocturnal pests, like me, the simplest, surest remedy is to place a long strip of copper tape on the ground behind them.  Slugs can't cross the copper.  No fuss, no muss.  Just keep it clean and wipe after a heavy rain, when the Slugs are like to come marching in by the truckload.  Copper stops them in their tracks.  I have too many Slugs to fiddle with a few containers of beer that people like to talk about.  I don't know who actually does this successfully.  You may catch 10 or 15, maybe 20 if you get really good at it.  But I am dealing with hundreds, and Copper tape is more effective for me and a lot less disgusting.

Another warning: DO NOT FERTILIZE your Begonias, not at least unless you see symptoms of malnutrition, which is highly unlikely unless you are using soil from the Moon.  And even then, I'm not so sure.  In one study of Begonias for use in office buildings, the researchers concluded that although temperature and light intensity could be used to improve flowering, 'Fertilizer rate had no effect on plant size or plant grade.'  They used Miramax and Osmocote, two Scotts fertilizers.  These tests are frequently commissioned or funded by fertilizer megacorporations, so this kind of study is unusual.

Just to cover myself here, behold the study, which I guarantee 100 people will be clamoring about after this posts on AllExperts:

mrec.ifas.ufl.edu/foliage/resrpts/rh_95_3.htm

See, If I don't post that, people will be writing that I made it up.  They'll write anyway, but it will have to be something else.  I repeat:  Fertilizer is almost always a waste of money and time. Now it's official.

Note for something later in the season: Begonias are also sensitive to cold.  Once temps get down to the 40s or low 50s, it's time to pot them up and move them to a warm window indoors.  Their chlorophyll does not function in air that chilly.  Keeping them cold is suffocating.

Biggest Summer disease of these plants: Fungus.  Several types attack Begonia leaves, given the chance.

In this case, and especially because you mentioned you have not had much luck with these plants, consider investing in a container of Serenade.  This is a liquid that you spray on susceptible leaves (I use it first on Roses and then on Peonies) to PREVENT Fungus attacks.  Once the symptoms appear, the leaves are history.  But if you spray faithfully, the Serenade will coat the leaves with friendly, Fungus-eating Bacteria.  I'm not kidding.  These Bacteria LOVE Fungus, they LIVE for Fungus, they will completely solve all your Fungus problems.  Just keep spraying all Summer, after every deluge of precipitation.  Don't fear the Bacteria; most are your strongest allies.  And your breathing them in as we speak; your immune system will intercept any that make you sick.  Those that hunt for plant-attacking Fungi are completely oblivious to anything else.  Isn't science grand?

Finally, if you have not gotten to know your Cornell Cooperative Extension Service, they do have a branch here on Long Island to cater to their Nassau and Suffolk customers.  Your tax dollars at work.  Here's a link to their cheat sheets on Begonias, although I disagree with their advice about compulsive fertilizing:

www.ccenassau.org/hort/fact_sheets/a129_begonias.pdf

I do apologize for not addressing your most recent question sooner.  I thought I posted a reply the day your question appeared, but it has apparently disappeared into some black hole, all my fault, and not to the AllExperts website as intended.  I am especially sorry because you had such lovely comments about my answer earlier.  It is so nice to read those things.  Thank you.

THE LONG ISLAND GARDENER