Establishing California Native Plants Using Root Watering Systems
December may seem like a strange time to talk about establishing California Native Plants, but right now-the winter-is the best time to plant them.
It's also the best time to set up the right irrigation for them so that they survive without much water in the summer.
This is because California Native Plants get their water naturally in the winter, and most of them don't grow much in the summer.
Instead they go dormant.
Getting through the summer is critical to the success of a garden planted with California natives.
The Controversy In the wild, California native plants are used to being dry.
Many of the most beautiful, such as Flannel Bush (Fremontodendron) or California Lilac (ceanothus), are susceptible to fungus that thrive in warm and moist soil.
At the same time, until such plants get established, they have a hard time finding the water to make it through the long hot and dry summers.
What to do? Earlier Solutions Avid gardeners have used two strategies for handling this problem.
The first of these is to create a well around each plant and fill the well, watering them deeply once a month during the summer-in San Diego this would be mid-June through mid-October.
If you have clay in your soil, or if you are using shredded bark mulch, this can mean that even once a month The second method is to increase the frequency of watering but use very light water that imitates summer rain, such as can be created using low-impact rotating spray heads.
Both these methods can work, but they have a limited success rate.
Inevitably, a high percentage of the natives die before they get established.
A New Solution About two years ago, I discovered Rain Bird had developed a product for watering trees and shrubs called their "Root Watering System" or RWS s Series.
These are essentially perforated tubes with a bubbler installed in each.
The smallest tube is about 10" long, and the largest is about three feet long.
Hunter makes its own version of the same product called "RZWS.
" The advantage of using these tubes with native plants is that the water percolates down into the deep soil right away and doesn't wet the top couple inches.
As the depth of the soil increases, the temperature goes down, and so this greatly reduces the problem of fungus.
The RWS is also highly water efficient since you don't lose practically any water to evaporation.
This is also a superb way to establish plants on slopes since the water doesn't run down the slope.
Tips for Using the RWS/ RZWS Series I like to wrap the tubes in landscape fabric and put a piece of duct tape over most of the lid to keep them from filling up with dirt too quickly.
Also, I mix decomposed with the existing soil around the plant ball, and I put pure decomposed granite down about a foot below the RWS tubes and about six inches out from the sides of the tubes.
Rain Bird's instructions are to place the tubes right against the root ball, but I think this is too close, and place them out about eight inches to a foot from the root ball.
In the summer, keep an eye on your plants.
Once a month is still pretty good advice for this time of year, but if the Santa Ana winds get really bad, you might want to up the frequency.
It's also the best time to set up the right irrigation for them so that they survive without much water in the summer.
This is because California Native Plants get their water naturally in the winter, and most of them don't grow much in the summer.
Instead they go dormant.
Getting through the summer is critical to the success of a garden planted with California natives.
The Controversy In the wild, California native plants are used to being dry.
Many of the most beautiful, such as Flannel Bush (Fremontodendron) or California Lilac (ceanothus), are susceptible to fungus that thrive in warm and moist soil.
At the same time, until such plants get established, they have a hard time finding the water to make it through the long hot and dry summers.
What to do? Earlier Solutions Avid gardeners have used two strategies for handling this problem.
The first of these is to create a well around each plant and fill the well, watering them deeply once a month during the summer-in San Diego this would be mid-June through mid-October.
If you have clay in your soil, or if you are using shredded bark mulch, this can mean that even once a month The second method is to increase the frequency of watering but use very light water that imitates summer rain, such as can be created using low-impact rotating spray heads.
Both these methods can work, but they have a limited success rate.
Inevitably, a high percentage of the natives die before they get established.
A New Solution About two years ago, I discovered Rain Bird had developed a product for watering trees and shrubs called their "Root Watering System" or RWS s Series.
These are essentially perforated tubes with a bubbler installed in each.
The smallest tube is about 10" long, and the largest is about three feet long.
Hunter makes its own version of the same product called "RZWS.
" The advantage of using these tubes with native plants is that the water percolates down into the deep soil right away and doesn't wet the top couple inches.
As the depth of the soil increases, the temperature goes down, and so this greatly reduces the problem of fungus.
The RWS is also highly water efficient since you don't lose practically any water to evaporation.
This is also a superb way to establish plants on slopes since the water doesn't run down the slope.
Tips for Using the RWS/ RZWS Series I like to wrap the tubes in landscape fabric and put a piece of duct tape over most of the lid to keep them from filling up with dirt too quickly.
Also, I mix decomposed with the existing soil around the plant ball, and I put pure decomposed granite down about a foot below the RWS tubes and about six inches out from the sides of the tubes.
Rain Bird's instructions are to place the tubes right against the root ball, but I think this is too close, and place them out about eight inches to a foot from the root ball.
In the summer, keep an eye on your plants.
Once a month is still pretty good advice for this time of year, but if the Santa Ana winds get really bad, you might want to up the frequency.