When it comes to water needs, all plants are not alike. After years of tinkering, I learned to regulate flow to each individual plant with 2 indispensable levers. One – tailoring emitters – customizes plants within a zone. The other, described here, customizes irrigation times and frequencies across zones. Both breakthroughs occurred as my confidence to diverge from experts grew and as my gardens developed.
Plant type, maturity, soil composition, and exposure all play a part in how much water is actually needed. You turn off irrigation when it rains until it’s dry again, right? And you increase run times in summer. Customization like I recommend here takes those concepts much further.
The table below illustrates this technique for my gardens. Large plants have two 1 or 2 gallons per hour (gph) emitters; small plants have a single 0.5 gph or 1 gph; ones that do better with infrequent hand water than drip have none. Primarily based on location, each zone gets made-to-order settings for how long and how often its irrigation runs. Settings in others’ gardens would be based on their weather and soil types.
|Zone||Description||Plant Types & Emitters||Exposure||Run Time*||Run Frequency|
|1||Hedges||pittosporum (2 2gph)
prunus (2 2gph)
|Part sun||46 min.||Once weekly|
|2||Knot garden||aeonium (1 0.5gph)
crassula (1 0.5gph)
dudleya (1 0.5pgh)
|Full sun||30 min.||Twice weekly|
|3||Terrace garden||succulents (1 0.5gph)
|Full sun||0||Hand water every 7-21 days|
|4||Steep slopes||rosmarinus (1 1gph) ceonythus (1 1gph)
|Fun sun||30 min.||Once weekly|
|5||Entry garden||echeveria (0)
salvia (1 1gph)
neomarica (1 0.5gph)
callistemon (2 1gph)
|Part sun||60 min.||Twice weekly|
All these plants are classified as low-water, yet they thrive on personalized consumption through tailored emitters and customized run time and frequency. By contrast, the convention of same treatment for all plants is easy, but bad for sustainability. And expert advice of same zone for similar species may be viable in large-scale commercial sites but not in smaller, diverse residential ones.
* Times shown are for May and June. Each is set at 10-20% less in cooler weather and 10-15% more in hot summer.