If the shrubs are established (ie, if they have been in the ground for 2-3
years), they probably don't need any supplemental water at all. (Except
perhaps in a prolonged drought - 3 weeks or more without rain). If they are
newly planted, they should get an inch of water a week, every week that you
don't get a rain storm where you are. After one year, they shouldn't need to
be irrigated anymore, unless several weeks go by without rain. All of this
is predicated on the idea that the plants are not underneath the eaves of
the house. If they are underneath the eaves, then you need to water them
regularly.
"Billy" wrote in message
...
I live in the NE USA and my front landscape consists of arborvitae's,
junipers, holley's, a bloodgood, a cherry blossom, various small plants,
etc. These all sit on the NE side of my home that gets mostly half sun/half
shade. The cherry blossom and bloodgood gets more sun, in the range of
about 3/4 sun and 1/4 shade.

Recently, I setup a neat little Nelson sprinkler system surrounding these
shrubs and set a timer to sprinkle them twice a day at 7am and 7pm, for 15
minutes each session.

Should I be watering these shrubs this often, this long, or at all?