The shrub type is also very variable and can range in size from miniatures to giants 12 feet tall. Some varieties have leaves up to 24 inches long under perfect conditions. The leaf surface is also variable and some have smooth shiny leaves and other types have hairy or felted leaves. This type gets its name from the way it grows with many shoots coming up from the soil to make a full plant like any other shrub you would grow. They are very multi-stemmed.

Most varieties do not bloom as often or as heavily as the cane type but there are many that are ever blooming and are used as bedding plants across the country. The shrub type is grown mostly for its ease of growing, interesting leaves, and full growth. Most shrubs have white flowers but there are plenty of pink and red ones also, and many have hairy flowers.

General Pruning Tips and Rules

1.  When pruning, especially canes and shrubs, you should cut out completely any stems that have multiple stumps from years of pruning.  This will force up a fresh new stem to replace the ugly one. I call these older stems stair steppers.   Also prune out any other stems that are unsightly.

2.  When pruning, always remove any stems or branches that cross over each other.  They won't look better with time and it's best to remove them right away as you see them.  Cut the offending stem back to a bud facing the other direction or if that isn't possible, cut it to the soil line and force it to start over again.

3.  When pruning to make a begonia into a shapely hanging basket you need to force only side growth.  Any new growth from the roots is almost always too stiff.  I've heard many new and old growers refer to these strong stems coming up in their baskets as sucker growth.  They thought the basket was trying to revert to something else.  That isn't true.  These strong shoots are the normal growth of the plant.  (see illustration H) It's the hanging part that isn't its normal pattern of growth.  Side shoots are always weaker than the upright shoots of a plant.  To keep your basket as a shapely basket, when these stronger shoots come up from the base, prune them down right away to the lowest outward facing bud.  This will force side shoots that will be weaker stems like the rest of your basket.  The reason for cutting them down nearly to the soil is because you want them to branch down inside the plant.  If you prune higher, they will branch higher. (see illustration I)  This won't create a nice shaped basket.  Remember a simple rule, if you want an upright plant, prune out side growth.  If you want a basket, prune out upright growth.

4.  As I said earlier, always prune to outward facing buds.  If you just prune to heighth without regard to the buds, as they grow out, you will have branches growing every which way, crossing over each other.  This will create an unsightly plant.  Begonias on a trellis should be pruned slightly differently.  You aren't concerned about branches crossing over because you want to cover the entire trellis.  With a trellised plant, first tie as many branches as possible to the trellis.  After you have done that, then you can prune the loose stems close to the trellis, down to an outward facing bud.  When pruning a begonia that will stay against a wall, in a corner, etc. then prune all the stems so the buds are facing towards the front of the plant.  This will force all the stems to grow against and away from the wall instead of into wall. 

5.  Although I have given you general times for pruning, you can really prune a begonia any time of year that you choose.  The problem isn't with the pruning, it's with the watering afterwards.  Since a begonia doesn't use hardly any water when all the stems are cut back and it has no leaves, it can be easy  to overwater.  This is one reason why fall pruning in warm areas can be a problem.  The winter rains can overwater the begonia before it has a chance to grow back.  In combination with colder winter temperatures, many begonias can winter kill easily.  No matter what time of year you prune, you should always be careful with the watering until the begonia gets growing again.  This is also the reason why many people have killed begonias when they pruned hard.  It wasn't the pruning, it was the watering.

6.  Safe Pruning.  If you are a hesitant pruner, either because you are a new grower or just haven't ever pruned much, there is a safe way for you to learn.  Instead of a light or hard pruning, do it in stages.  This will get you used to doing the pruning until you learn just how much you can prune off without killing the plant.  To prune in stages, first just take tip cuttings like you were taking cuttings to propagate with.  This will force the plant to send out side growth and maybe even new shoots.  After this happens prune a little more and farther down, maybe even a few stems at a time if you are really hesitant.  Pruning just parts at a time you will eventually get the begonia cut down to where you want it.  This will also give you a chance to see just what happens when you cut a stem, etc.  Also, since you started with the tip cuttings, these will probably have already rooted and be potted up so that if you really make a mistake, you do have the cuttings to fall back on.  You really shouldn't have those kinds of problems though, but better safe than sorry, especially when first learning. 

7.   If you have begonia standards (formed into small trees), they will require a little more thought when pruning.  You want to prune them fairly hard because otherwise they'll get overgrown and not be able to support the long branches.  On the other hand, make sure you leave quite a few buds so there will be something left to grow out after the pruning is done.

8.  You can apply these pruning methods to many of the plants in your garden such as roses.  I prune my roses and begonias the same way as a general rule.

Above information is from Brad Thompson