Drip irrigation and drought tolerant plants
I moved into my home here on Whidbey Island two years ago this summer. The house has over 100 years of history and the gardens reflect many owners' inputs and additions. There's an extensive drip irrigation system in place for watering, but it shows little rhyme or reason.
Today's project is to tweak the drip system so it quits dripping on bare soil and starts dripping on plants that need irrigation.
My question is, should my Ceanothus, lavender, spring bulbs be excluded from the drip system? We get some *really* droughty summer stretches here in the rainshadow and I'm wondering if I shouldn't leave a single dripper on at least some of the plants (I run the system for 1.5-2 hours and they're 1/2 gph drippers). Oh, how about Germander/Teucrium chamaedrys? I have a ton of it, and some is already excluded from the drip system and still doing fine.
How about established trees and tree-like shrubs? I have some Rhododendrons, Buddleja, and a Dogwood that aren't blooming well, as well as a Katsura tree that suffered a lot of die-back but is recovering, and I suspect insufficient moisture as one contributing cause -- I was figuring on upping them to 2-3 drippers per plant?
Thank you so much for any input you can offer! Finally this is the year I put my *own* stamp on the gardens here. :)