TOMATOES – PINCHING BLOSSOMS AND/OR PRUNING PLANTS?

Two-foot tall tomato plant with good amount of foliage has an established root system, so blossoms allowed to set fruit.

Alstroemeria and nasturtium

Before: Peach set needing thinning.

After: Peaches thinned to opposite sides of the branch and far enough apart so they won't touch when they reach their mature size.

Double Delight Rose

When I was helping at the Tomatomania events, I was frequently asked about pinching and pruning tomato plants – whether to, how to, and when to.  My response was “It depends whether your garden is on the coast or inland.”  If on the coast, then some pinching of blossoms and shoots at nodes is wise, to promote better air circulation and enable more direct sun onto the fruits.  But, if the garden is inland, then pruning is a bad idea, aside from pinching blossoms for a month following transplanting.
 
Here’s why, in both cases.
 
Do Pinch Off Blossoms – For A Month After Planting
 
This is the case for all tomato plants and all garden locations, since it’s dealing with establishing a strong plant that will be very productive.
 
Pluck off all blossoms and any fruit for at least a month after transplanting, until the plant is at least two feet tall so it’s forced to direct its energies toward establishing a strong root system.  If blossoms are allowed to develop fully and then set fruit, the plant will expend its energies on fruit production at the expense of establishing a strong plant that will be able to produce many more tomatoes.  This is the case whether the plants are "determinate" (they grow only to a determined height, set their blossoms,  ripen their fruit, and then the plants die), or "indeterminate" (they keep on growing and bearing flowers and fruit until killed by frost; although they may poop out before then due to lack of nutrients or warm-enough weather). 
 
Whether To Prune Plants Depends on Where The Garden Is Located
 
The concept of pruning plants is an East-coast and Midwest thing based on two environmental conditions there that we have somewhat on our coast but the opposite inland.

1. Constant moisture.  Summer humidity that the East and Midwest is infamous for means that plants without sufficient air circulation will more likely develop plant diseases, so the recommendation is to prune out suckers and “excess” foliage. Because our coast also has frequent/constant moisture, some pruning may also be wise. Inland, however, our lack of general humidity and sometimes extremely dry air precludes this problem.  The only precaution is to locate plants far enough apart for good air circulation, especially for varieties that become large when they’re well-nourished.
   
   
2. Lack of direct sun. That same East-coast and Midwest humidity means that there’s a generally overcast sky, so pruning is recommended so more sun can reach and ripen the tomato fruits.  This is also the case on our coast.  Inland, however,  our abundance of direct unfiltered sun is almost too much of a good thing – we need as much foliage as possible to shade our tomato fruits from sunburn.