barn owls control gophers

“Can you suggest a plant that repels gophers? We have a large number on our embankment and they are starting to create a real problem. Also, previously you had reported that New Zealand flax is drought-tolerant.
Where can I purchase them locally and are there other similar plants? I do not want anything that grows more than 4 feet tall.”
There is no plant that has been proven to repel gophers. Although you think there are many gophers on your embankment, there are probably only one or two. Gophers are highly territorial and even though you might see many mounds with their adjacent gopher holes in a fairly large area (up to 1000 square feet), you are probably looking at the work of a single animal.
I do not know if you have dogs or cats but there is evidence suggesting that these pets, especially when several of them are allowed to roam the yard, provide a significant measure of gopher control.
You also can encourage barn owls, which are always in the vicinity searching for gophers and other rodents, to take up residence in your back yard by building a nesting box for them. Find instructions for doing so at www.rain.org/~sals/barnowl.html.
You should be able to find New Zealand flax at most neighborhood nurseries. If they are not in stock, you should be able to special order them.
There are many varieties that grow no more than four feet tall, but I would stay with the bronze, brown or green and yellow striped varieties in Sylmar. “Dark Delight” and “Yellow Queen” grow to four-feet-tall with arching foliage and “Jack Spratt” stays under two-feet-tall. When growing flax anywhere in the Valley, if you wish to avoid burnt leaf edges, plant them in half-day sun. You can grow the showier types with the pink and cream coloration if you keep them in containers and quickly remove leaves whose color fades. As for companion plants to New Zealand flax, I would consider the soft-leafed agaves, both the green Agave attenuata and the blue Agave “Blue Flame,” as well as almost any Aloe species, whose orange flowers contrast nicely with bronze flax foliage.
“I planted a hedge of wax-leaf privets six years ago along a cinder block wall. They all grew slowly but surely for about the first 2-3 years. Right now about 2/3 of them are doing great but, at one end, they are dying. It started with one bush dying over a period of about 4 months. After that one was almost dead, the adjacent plant started to die and so on.
I have been talked into adding gypsum and sulfur to counteract the lime that has been leaching out of the foundation of the cinderblock wall. I have tried heavy watering once a month. I have tried weekly light watering. None of this seems to make a difference.”
– DIANA ROSE
Sylmar – RICHARD ROSEN
Simi Valley
Soil near a block wall tends to be highly alkaline and compacted. When soil is highly alkaline, wax-leaf privet shows signs of iron deficiency chlorosis (yellow leaves with green veins).
Compacted soil also suppresses absorption of iron by roots. With insufficient iron in their leaves, plants cannot produce food through photosynthesis and may die. If you have a soil borne fungus, it would move with the water from one end of your hedge to the other, especially if you have a sloping terrain. Keep watering to a bare minimum. Remove plants as soon as they show signs of stress and dig up and dispose of soil that surrounds their roots. I would also top-dress soil with compost or Nitrohumus to improve drainage.