Question
QUESTION: Hello, I have two large potted jasmine (one is Confederate, other don't know)in an inner patio in Mexico where the climate is high desert dry and hot.  Have had the plants 5 years.  They're trellised, protected by a solar cloth that lets in light, but reduces UV by 85% and a fan running over water (a "swamp cooler") during the day, bark on the soil surface to help hold moisture, mist them every other day. This past year, they've had problems with leaves crisping and falling off. The leaves are still green, but dried up. Over or under-watering? The Confederate has been showing hard white dots on the stems and leaves and I have been treating with a fungicide. The other shows no sign of fungus or insects. I give them both a diluted liquid fertilizer twice a month. They flower only a little and poorly. They survive, but don't thrive. Suggestions? Thanks!

ANSWER: Hi Jan,

Confederate Jasmine do not usually thrive in hot, dry climates. They prefer cooler, humid environments such as those found in the southeastern US and parts of Asia. They do like lots of bright light, but not the high temps that may go along with direct sun. It is possible that your solar cloth is keeping out too much light and thereby preventing flower development.

The symptoms you describe are generic with several possible causes, including improper watering. I don't know how your plants are potted and your watering routine, so I cannot tell you specifically how to water. However, if you have potted your plants in large pots then that may be causing root rot and preventing healthy new growth.

I don't know of any fungus that could be described as "hard white dots." I am not sure what that is, but it is not a fungus and not a standard plant pest.

Overall, I think you may be fighting a losing battle in your high desert climate.

I have written an article on caring for indoor Jasmine that I will email for free to you (or anyone else) who emails a request to me at [email protected].

Please let me know if any of this is unclear or if you have any additional questions.

If this information has been helpful, please click the Rate Volunteer bar below and enter a rating and nomination for me. I am a volunteer on this site so Ratings are the only compensation I receive for answering plant questions.

Need more information? Visit my website at:
A link to PlantCareExperts.com

or email me at [email protected] or call me at 917-887-8601 (EST)
 
Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

Visit my website at: A link to PlantCareExperts.com



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

QUESTION: Thanks for responding so quickly. Sounds hopeless!  But I HAVE to try and help them survive; Have had them for so long they're practically family members.  About the pots and watering routine:  the 8 ft. unknown jasmine is in a 12" (at the rim)pot,which bulges out to about 16, then tapers back to a base of 12.  The 12 Ft. Confederate is in a 16" pot of similar proportions.  Both pots are 18" deep.  I water and mist both plants every other day. I realize under or over-watering often show the same kinds of stress.  How can I tell without killing the plant in the process? If root rot has set in, how can I identify and remedy it?  Repotting would be a huge chore, but I'd be willing to give it a try if you recommend it. The daytime temp reaches as much as 92, evening around 60 during the hot season.  I read in a forum that others have described the very small white-to-yellow hard dots. One response suggested that it is evidence of an INTERNAL fungus in the stalks, but mentioned no possible remedies.  If this is the case, do you know how I might treat an internal fungus? I'll send for your article right away. Thank you, Mr. Creed!

Answer
Sorry, I didn't mean to imply that keeping your plants alive was hopeless. It is flowering that is problematic and that is the primary reason for having these plants.

The pots you describe are quite large. Because of their odd shape, repotting is not a practical option. The risk with large planters is that the soil does not dry out sufficiently to allow essential oxygen into the root zone. If you used a heavy potting mix that contains soil, not peat moss, then the risk is even greater. Given the odd pots, your local outdoor conditions and not knowing the soil quality makes it impossible for me to advise you on the watering regimen. Just be careful that root rot is not occurring deep inside the root zone. Depending on how much water you are applying, it is likely that watering every other day is too much.

On-line forums are filled with amateurs who make uneducated guesses and sometime just make stuff up out of whole cloth. Of course, they always make their observations with great authority. The dots are not an "internal fungus" and fungicide will not help.

Misting dies no harm, but it does virtually nothing to increase humidity unless you mist several times every hour all day long.

~Will