Thats somewhat tuff to answer ???

Any more info ???

Here in Vegas where down to 1 day per week ... like it or not due to the drought...... temps lows 38 - 40 , highs 60 - 64 ..... What are you watering ? .... get out and check the soil.

Trees,shrubs,bamboo,vines,flowers.

What SPECIES?

Native? Not native?

I've heard once a month in the winter. Heard it on tv, I think on the weather report several years ago.

Here in the mountains of northern NM, the ground on the shady side of my house stays frozen, but the sunny side dries out quickly. I was told to water my new (seeded last Aug) blue gramma lawn once a month, but had a lot of trouble in the areas where the ground was frozen. For shrubs, etc. I've heard the 'once a month' thing, too, but again need to be selective because I think it does more harm than good to flood an area that can't/doesn't soak up the water before nighttime freezes. Fortunately, it's a moot point since early/mid February and I now have snow on the ground and water from the skies!!!!