I'll just share a little advise that may be helpful to folks that may be new to bonsai and could use a few pointers when it comes to watering bonsai.  Watering bonsai is an art that takes some time to master.  Let me first start by sharing something with you that I often tell the many that visit my collection.  That is that my favorite activity, the one I enjoy most of all is watering my trees.  My bonsai seem very happy that I've taken a fancy to this watering thing, because it seems it's what my bonsai like the best also.  Bonsai have feelings too and believe me I have seen some pretty sad trees in the past twenty years.   If I'm working with others offering guidance, I have often been known to say "Bring tree back next year when it might be healthy".   A well-maintained collection may have a few trees that may be stressed and some collections may have up to 100% of the trees under stress.  Also keep in mind that it could take all season for a tree to recover from just one poor watering.  I have one tree that is on its third year of recovery from improper watering.  As much as we love our trees and work hard to study the  art of bonsai, we should also study and master the art of watering our bonsai. 

   Now let me share a little of my watering methods.  I do not actually pick up my watering wand & begin watering my trees.  At first, I inspect trees for moisture loss, new foliage growth and gather some insight as to my approach for watering collection on this day.  I prefer early morning or evening watering.   In hot weather, I prefer to water in evening hours.  A good watering rose is essential for all trees, even with container prestock plants.  Take your time and keep focused on the task and the individual needs of each tree.  Take some time to organize your collection.   Keep small trees close to water source and away from larger specimens. One-gallon plants should be with one-gallon plants and not mixed in with larger specimen since they will need water often.  I keep my deciduous in one area close to water source and use different hose stations.  I prefer to use only one center isle and line plants out on both sides of this walkway.  This allows you to save time without walking down many short rows to water plants.

     When you are finished watering inspect your work.  Take a plant and slide it out of container to access your work.  There should be no dry areas in root mass.  If there are dry spots, there may be problems with soil media or you are not watering long enough.  Often these dry spots are from water take up in one part of container and wet areas are dead zones of inactive or dead roots, these dry areas can soon have problems.  At least twice a season I use a wetting agent, which will prevent unequal distribution of water, allowing water to move into these dry zones.  Wetting agents are detergent-like substances that reduce the surface tension of water, allowing it to penetrate and wet the soil more easily. 

    Keep your area clean of plant debris and weeds.  At times before watering you can weed and sweep down area.  This allows you to closely inspect health and access your previous watering.  You'll find that this is a great time to prune a few plants or pull a couple of trees that need to be in bigger pots.