Q. We got your email from our son in law who recommended www contact you. We have a saguaro the has been in place for 10 years or so. A couple of months ago, it started leaning and now is in danger of falling over. We staked it but are not sure what to do. We were told it might be rotting from below although it looks ok. It is about 6 1/2 feet from the pool but there doesn’t seem to be any water near it. I am attaching a couple of pictures. We would appreciate any advice or insight you can give us.
A. The usual reason that saguaro might lean are related to water. If the plants are getting water too often then this can cause root death due to suffocation. Roots are important for anchoring the plant in the soil and they might lean with root damage.
I would not water more often than once every three weeks if you are giving it lots of water each time. If you are very, very careful you might get away watering more often but with less water but the water needs to be applied up to at least three feet from the trunk.
Also, if water is applied close to the trunk and the soil is dry outside of this area then roots develop close to the trunk but no further out. As the plant gets tall and “top heavy” the roots do not provide enough anchorage, they are not spread out enough, and the plant begins to lean.
While you are staking it, add more emitters further from the trunk to encourage the roots to spread. They should be about 18 to 24 inches apart to provide even coverage of water to the soil. I couldn’t tell from you picture but the second option looks more likely with what I could see in the picture.