[Arid_gardener] RE: yellowing cacti

[Donald Garnett]

Dear Luann,
 
Your cacti are almost certainly being overwatered. Cacti have adapted to
the arid desert by storing water in their stems and can go many days without
watering. Watering them for an hour every day is essentially drowning them.
Too much water will destroy their roots so that they can no longer take up
water and nutrients from the soil. 
 
If your cacti are planted in the ground, and you have them on a drip system,
I suggest that you plug the emitters to the cacti, and hope that they recover.
If they do, then you can water them once every 3-4 weeks only in the summer
time, never in winter. Cacti will tell you they need water by getting skinnier as
they use their stored water - but they can go pretty far before they succumb.
 
Note: depending on what kind of shrubs you have, watering them every other
day may be too much as well. Most plants need to have the soil dry out a bit
between waterings, which allows them to take up nutrients. If you have 
desert-adapted shrubs, you might consider lengthening the interval to 1-2 weeks.
Your plants will be happier and you'll save water too!
 
    Don Garnett
    Tucson
> Message: 7> Date: Sun, 1 Jul 2007 08:33:33 -0700 (PDT)> From: luann torkelson <luanntorkelson at yahoo.com>> Subject: [Arid_gardener] cacti question> To: arid_gardener at cals.arizona.edu> Message-ID: <350434.31601.qm at web38410.mail.mud.yahoo.com>> Content-Type: text/plain; charset="iso-8859-1"> > Good morning,> > Our yard was landscaped in April 2006. We have two cacti about four feet apart; each gets full sunlight all day. Their watering schedule is on the same cycle as all shrubs: 1 hour every two days.> > Here is the question: The argentine giant is all shades of yellow. The organ pipe is beginning to get yellow on the tips and near the base. What causes the yellowing and is > there anything I can do about it? Both plants are below the knee in height.> > Thanks.> Luann
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