Mexican fan palms yellowing

[Asa]

Hey guys I recently bought some Mexican fan palms in zone 7a-8ish Chattanooga TN. I planted these palms almost 2 weeks ago. I bought them from the tree Center online and they came severely root bound in small pots and some of them did have some root rot that I had to trim off but not much. Anyway these palms are yellowing on the fronds. I water them every other day since we are in the high 90s. We had an extreme week of sun that just destroyed them so I made a quick diy shade protector (didn’t know what I was doing and looks ugly). I didn’t give them a proper acclimation period either. Please help me.

[SeanK]

I think you've done all you can. Please don't fertilize yet.

[MJSanDiego]

I really don't want to be the bearer of bad news but I think you should be aware that you cannot successfully grow a Mexican fan palm in zones 7a, 7b or 8a. It doesn't matter that you bought them locally. Here is what will happen. When your temps get below 20F it will suffer 100% leaf damage which means every visible frond will be crispy brown for months until your spring when perhaps new growth will emerge. Each year it will suffer like this and it will stunt its growth or eventually perish, not to mention it is unattractive for months each year. You bought a Washingtonia Robusta. What you need is a Washingtonia Filifera for zone 7a to 8. Sorry to give you bad news but you can research to confirm this. l I am just trying to help. I have planted many palms in many zones over the last 2 decades and I have also made many mistakes that I learned from

[Slifer00]

Don't water them everyday, other than the days after transplanting. Mexican fan palms need very little water. Even if you box them up come winter, I doubt they will survive

[RJ]

On 7/16/2024 at 6:36 PM, MJSanDiego said:

I really don't want to be the bearer of bad news but I think you should be aware that you cannot successfully grow a Mexican fan palm in zones 7a, 7b or 8a. It doesn't matter that you bought them locally. Here is what will happen. When your temps get below 20F it will suffer 100% leaf damage which means every visible frond will be crispy brown for months until your spring when perhaps new growth will emerge. Each year it will suffer like this and it will stunt its growth or eventually perish, not to mention it is unattractive for months each year. You bought a Washingtonia Robusta. What you need is a Washingtonia Filifera for zone 7a to 8. Sorry to give you bad news but you can research to confirm this. l I am just trying to help. I have planted many palms in many zones over the last 2 decades and I have also made many mistakes that I learned from

Sure you can in 8a. there is a 30’ one down the road from me, many 50’ specimens in Columbia , SC. Sure they haven’t been there since the mid 80’s freezes but I consider 40 years a pretty good stretch. This one below is most likely a hybrid. 
 

This one is in Columbia SC. 
 

 

[MJSanDiego]

5 hours ago, RJ said:

Sure you can in 8a. there is a 30’ one down the road from me, many 50’ specimens in Columbia , SC. Sure they haven’t been there since the mid 80’s freezes but I consider 40 years a pretty good stretch. This one below is most likely a hybrid. 
 

This one is in Columbia SC. 
 

 

Are you sure they are all true Robustas (mexican fan palms)? Could be Filiferas or Filibustas?

[RJ]

3 hours ago, MJSanDiego said:

Are you sure they are all true Robustas (mexican fan palms)? Could be Filiferas or Filibustas?

As I stated above  they’re most likely a hybrid, true of either are pretty difficult to get as pretty much everything from the big box stores is a hybrid now.
 

They’re even some specimens with water proximity north of me in charlotte, nc. Fayetteville, NC is home to one that is often talked about in the cold hardy section of PT. out in the open all alone. Augusta Ga is home to a lot as well. 

[Las Palmas Norte]

Check out some YouTube videos on Washingtonia in cold winter climates. There's plenty of palm enthusiasts growing them successfully with the right methods.

Soil moisture must be deep enough to allow intake at all points during this transplant phase.

[Slifer00]

17 hours ago, RJ said:

Sure you can in 8a. there is a 30’ one down the road from me, many 50’ specimens in Columbia , SC. Sure they haven’t been there since the mid 80’s freezes but I consider 40 years a pretty good stretch. This one below is most likely a hybrid. 
 

This one is in Columbia SC. 
 

 

According to the USDA that is located in zone 8b/9a, with the added benefit of a huge disparity between day and night temperatures!

[RJ]

51 minutes ago, Slifer00 said:

According to the USDA that is located in zone 8b/9a, with the added benefit of a huge disparity between day and night temperatures!

The 2023 map puts Columbia in 8b, 8a for to 2012 map, and boarder line 7b/8a for the 1991 map. No way it’s a Z9a. These palms are all 20 plus year old trees so the latest zone map is moot. 
 

Sorry, I’m not sure what you mean by …”with the added benefit of a huge disparity between day and night temperatures!”  
 

 

[Silas_Sancona]

To the OP,  what you're seeing looks -to me- like they're going through their initial adjustment phase, and will  snap out of it as you head into fall.. Remember,, these grow anywhere ..everywhere here ..in every size and even the youngins' that pop up in people's gravel gardens will show a lil' yellow this time of year. 80s -90s ..or even the occasional high touching 100 is nothing compared to our 105-110++ highs / upper 80s-upper 90 deg lows this time of year. Tack on that back east, you all have much more consistent  humidity levels than we do. More humidity helps protect leaves from burning.. 

Regardless, ..i too think you'll be fine. Definitely recommend protecting as has been recommended by others back there this winter ( at least ).

Regarding growing in below 9 zones? ..Agua Caliente Park, in Tucson sits in a sometimes brutally cold pocket along the Tanque Verde Wash on the far east side of Tucson.  While it doesn't happen every  year, have seen low temps bottomed out in the upper mid teens in the area where the park is located when checking temps on a cold morning region -wide.

Unlike Tucson proper, Tanque Verde area, inc. where the park sits, is a series of undulating set of wave -like hills and troughs ..Troughs are where the cold air spilling off the Catalina Mtns ..Which literally form a wall against the north and east side of the park..  pools, inc. where the park sits.

If you take a look at pictures from the park itself / pictures i've shot on visits to.. and posted here ..from there ..Washingtonia  GALORE ..and they're all healthy as can be, even the individuals that are growing right next to...  ..or in the water..

Have seen / seen when street view touring  pictures of tall W. robusta ( ..though they could be hybrids too ) in 8b 8a areas of AZ closer to the border where it can get down into the teens ..and they get snow -more often than Tucson can-

Yes, there are some big differences between our climate ( Typically dry in winter, esp. the further south one goes, Majority of chilly mornings are followed by mild or ..sorta hot.. afternoons ) and yours ( ..and what i experienced while living in Ohio ) but, i too think you can be successful ..As RJ mentions, others nearby, who might experience similar conditions you might see at times during the winter back there have / are growing them w/ out too much trouble.

Longevity?  ..You get 20 - 40 years ..or 80+ years out of those?  Worth it, 1,000%    Ignore ( and maybe chuckle at )  the Buzz Killingtons who constantly worry about some lurking in the corner super freeze that might come ..some day..  A planet destroying asteroid impact might  happen some day too.

Protect, if ..or when..  you might need to.  Otherwise,  enjoy being bold enough to not be afraid of giving them a try.. 
 

[Slifer00]

17 hours ago, RJ said:

The 2023 map puts Columbia in 8b, 8a for to 2012 map, and boarder line 7b/8a for the 1991 map. No way it’s a Z9a. These palms are all 20 plus year old trees so the latest zone map is moot. 
 

Sorry, I’m not sure what you mean by …”with the added benefit of a huge disparity between day and night temperatures!”  
 

 

Looking at it again, it seems I misinterpreted the colours! My apologies. You are right, it is zone 8a/8b, the annual average minima temperature at the airport station is 16.7 fahrenheit.

South Carolina has a huge disparity between day and night temperatures, meaning these cold temperatures are usually short lived, heating up quickly during the day. In comparison to somewhere like the PNW, mexican fan palms would struggle to even survive in a 9b climate

[MJSanDiego]

I know these are already planted but I am surprised no one mentioned the spacing. I think most would agree these are located too close to the decking. I don't see how you will be able to walk along the decking in the near future. The crowns get pretty big and wide, lenth of the fronds, etc. Not to mention the thick sharp thorns on the petioles. Just something to consider. I've made many mistakes and had to take palms out. When they are small it's hard to visualize the future growth of this fast growing species

[jwitt]

Here are some examples of robusta, possible hybrids, growing in z 8.  First pic is Alamogordo, which saw -10f and second is Las Cruces which saw -5f. Both pics are a couple years after those temperatures. 

I can not grow robusta in my warm 7b without protection. I suspect Chattanooga will need protection also thru the coldest temperatures most winters. 

[MJSanDiego]

9 hours ago, jwitt said:

Here are some examples of robusta, possible hybrids, growing in z 8.  First pic is Alamogordo, which saw -10f and second is Las Cruces which saw -5f. Both pics are a couple years after those temperatures. 

I can not grow robusta in my warm 7b without protection. I suspect Chattanooga will need protection also thru the coldest temperatures most winters. 

It's so hard to tell from a distance, but very easy to ID upon close examination.  They don't look like Filifera based on the trunks, so I am thinking Filibusta, which can closely resemble Robusta, but the cold tolerance of a Filifera

[jwitt]

Leaves also look robusta.

[MJSanDiego]

Curious!! I don't know how you grow a Mexican Fan Palm  (robusta) in zone 7a or 7b. 15 years ago I couldn't even grow one successfully in zone 8a. Every winter it would defoliate around 22 degrees and I'd have an entire crown of crispy brown potato chip fronds until a new spear finally emerged in spring. There was no way to cover it as it's too tall so I don't know how you can do it especially when it gets 6 feet taller and up. Someone said some box method but how does that work on a 10+ ft tall palm? I would love to hear how this is all done.  Very curious!