Brown Spots on Phoenix Theophrasti

[acaipalmseeds]

It's been a wet year here in Michigan, so I haven't watered as frequently as I would in a normal summer.  The soil drains quickly.  Do these spots look like a result of too little or too much water? Bad nutrient mix? The soil is topsoil, palm soil, and some manure.  It seemed to do great all winter indoors.  I read on here that it is a thirstier form of Phoenix, so I have my doubts about overwatering causing a fungus. 

Edited June 15, 2019 by acaipalmseeds

[acaipalmseeds]

[UK_Palms]

Hey Acai,

I also get this black spotting on my Chamaerops as well as my various Phoenix's. It is nothing major and you should not lose any sleep over it. I believe it is just a consequence of growing these palms in a wet, humid climate, which promotes moulds/spores/pathogens etc, and there isn't really anything you can do about it. 

Theophrasti drinks a lot of water in the warmer, summer months (as do CIDP), but definitely cut back on the watering during wet spells, especially if the temperatures are low as well, and try to keep the palm well ventilated and both the fronds & spear dry, if possible. This should help to limit the spread of this issue. I doubt it is related to excessive water though as Theophrasti in their native range, grow with their trunks and roots completely submerged in water and are fine. So it must be a result of the humidity and rain on the fronds. 

Keep an eye on the issue and report back if it continues to get worse, or if it begins to improve.  Personally, I think your Theophrasti looks pretty healthy in those pics, minus the small black spotting on the fronds. 

[Rickybobby]

I’m. Not that far away from you it has been a horrible spring start to summer. An record lows and rain fall. Great Lakes are so high. Lots of flooding. Not a good palm year for us. (So far!)

[kinzyjr]

@acaipalmseeds We were having a discussion about this issue on this thread in the Cold Hardy Palms forum:

Phoenix Theophrasti Leaf Spot Disease

Seems that certain provenances yield more resistant plants.  Time will tell.  Steve's advice on the thread above may be of some help to you as well.

[acaipalmseeds]

[UK_Palms]

The Theophrasti looks fine. As long as you protect it from December - March, whenever the temperature drops below 25F and keep it relatively dry during this period, it will be fine. 

As I previously mentioned, the brown spots are probably just some kind of fungal issue from the rain and humidity. I get the same thing on my Chamaerops and Phoenix's. Our climates are just a bit wetter than they are used to in their native range.

Can I just ask where you got that Theophrasti from? Going by the pictures you have uploaded, it looks more like a CIDP than a Theophrasti. Possibly a hybrid? Or maybe its just a rather green looking Theo specimen. The fronds usually tend to be quite blue/grey. You'll know if its a Theophrasti when it starts suckering, or not...

[Merlyn]

I've seen spots like that on a couple of Phoenix species in Central FL, mostly on Canariensis.  It seems to only get bad on palms that don't get enough sunlight in the winter months.  Overhead watering might contribute to fungal growth, so a drip irrigation might help on cold months or indoors in the winter. 

I bought a Canary that was sitting off in a nursery's shady corner, it had worse black spots than your photos.  I put it in a spot with full sun from 10am-3pm all year and gave it a big soil drench of Banrot systemic fungicide.  All the new fronds coming out are flawless, but of course the older ones won't "heal."  After ~14 months of growth I'm about to cut off the last of the original spotted fronds and it should be totally free of the fungus.

Edited June 17, 2019 by Merlyn2220

[acaipalmseeds]

Thanks for the tips. I will look into the Banrot This is from North Texas Cold Hardy Palms.  About not being 100% Thephrasti, I guess it's possible, if the seeds are from Crete, Turkey etc. some other pollen crossed the palms.  I did notice that it grows quickly during winter and in chilly weather.  I am happy with it besides the spots, that happen while it is growing quickly and a bright green. 

[kinzyjr]

If they are from @TexasColdHardyPalms they are legit.  I bought a bunch of theophrasti seeds off him before and continue to buy from him first when possible.  I did have an issue with an order from an oversees vendor who sent me dactylifera seeds instead.  I've had both colors come out of the same seed batch - blue/grey and deep green.  The current batch I have planted are more green.  Thanks again for the tip @Merlyn2220.

[Steve in Florida]

On 6/15/2019 at 10:23 AM, acaipalmseeds said:

It's been a wet year here in Michigan, so I haven't watered as frequently as I would in a normal summer.  The soil drains quickly.  Do these spots look like a result of too little or too much water? Bad nutrient mix? The soil is topsoil, palm soil, and some manure.  It seemed to do great all winter indoors.  I read on here that it is a thirstier form of Phoenix, so I have my doubts about overwatering causing a fungus. 

Manure, heat, plus ample moisture levels is ideal for mass production of phytophthora.

Edited June 17, 2019 by Steve in Florida