Question
QUESTION: Hi Donna!
I have two mature Datura plants, both with the same obvious problem.  The bases of the plants are quite healthy, but for the last 2 years all of the leaves that do sprout quickly fall off.  The new stem growth withers and dies.  One of the plants has healthy, green growth for about 18" up from the ground, and the other is healthy and green for about 24" up from the ground.  Above that, the branches tend to wither, and any new growth quickly withers and leaves fall off. They are both in full sun and were very healthy up until a couple of years ago. No flowers!  Unusual for Datura, which usually has beautiful trumpets.  Any idea of the cause?  I want to save these beautiful plants before it is too late!  Thanks for any help you can give. If you can't help, but you know of someone who might be able to make some suggestions, please pass this email along as I want to save these plants before they die. Sharon, San Jose, CA.

ANSWER: Hello Sharon,

I'll bet I do know! Datura and brugmansia have a common enemy, which does not kill the plants but makes the leave fall off, particularly at the top.

I think you have spider mites. I've had this problem too (I'm, in fact, having it now!) Please do something for me. Go to your plants and see if you can spot almost microscopic webbing. And possibly very tiny white or red things on top of and, particularly, under the leaves. You have to get very close to see them.

Spider mites like heat and dryness. One of their enemies is dampness. I am fighting mine by spraying them with cool water. Direct a cool water spray from under the leaves upward. Do this, at first, every day, and then once a week.  You can also use insecticidal soap, or all season oil (not dormant oil, which will burn the leaves). The latter two can be used once a week. Applying them in the cooler air of the morning is best. Again, direct the spray from underneath the plant leaves. They hide there.

They will not kill your plants - they will only weaken them.

Is this clear? Please feel free to write again.

Donna

---------- FOLLOW-UP ----------

QUESTION: Hi Again!
Many thanks for your help.  I don't see any webs, but then the plant don't have any more leaves left! ! !  I guess I'll try spraying the plants and see what happens.  One of the plants has gone from an 8' tall plant down to the primary stalks which are about 24" tall.  I keep cutting back the dead growth.
If you get any other ideas please let me know. I really treasure these plants and I don't want to lose them. One was cultivated from the mother plant which was brought from Mexico as a baby by my Mom more than 20 years ago.  She is gone now, and the plant is not doing well, so I really want to save it!  I'll try anything.  Not much to lose now.  The growth up from the ground is healthy, but it is "sinking fast".  The other plant was bought from a local nursery and grew very well at first, but they are both planted in the same area and are now facing the same dilemma.  I have got to find the solution fast!  Thanks again!  Sharon

Answer
Dear Sharon,

Let抯 look at some other causes of leaf drop:

Drought stress: with insufficient watering the stem will remain but the leaves will drop. What is your watering schedule? I have experienced this too.

Or the opposite:
Too much water and not enough drainage. Is your soil free draining?

And lastly (and I think this may be the real problem):

These plants are heavy feeders. It is possible that they were more heavily fertilized before you received them, and they are not getting enough fertilizer to keep them happy. At this time of year they need weekly fertilization.

Would you tell me about your fertilization schedule?  I suspect that your plants are hungry.

Donna