Sylvester Palms in Corpus Christi, TX

[SoTXPalmNovice]

Hi there!  I just found this forum when searching for palm fertilizer.  I need to feed my Sylvester Palms, and want do know what’s best for them and for encouraging fruiting without damaging the lawn and flowers around the trees.  Your suggestions are much appreciated.  
My palms have 2-3’ trunks with gorgeous fronds, mostly.  Some are yellowing/browning on the lower limbs. 
I use LeafGuard on the fronds to protect from cold and plan to use it to protect from the heat, winds, and over drying.  What else can I do to make my trees happy and healthy? 
 

[Merlyn]

@SoTXPalmNovice welcome to PalmTalk!  Sylvesters are pretty tolerant of fertilizer, but also tend to get yellowed leaf tips from Magnesium deficiencies.  So a good "palm special" type fertilizer is the best choice, with a good mix of micronutrients like Magnesium, Manganese, Boron, etc.  The standard recommendation here is an 8-2-12 ratio like PalmGain or Florikan.  With those ratios 1.5lb of fertilizer per 100sqft of canopy space is good, sprinkled evenly 4x per year.  So for a 12' diameter Sylvester that's 3.14 * 6 * 6 = 113sqft of canopy space.  So 113 / 100 * 1.5 = 1.7lb of 8-2-12 for each palm.  Obviously this is just a good rule of thumb, so it's not like you need to take a scale out and get it super accurate.  Other fertilizers are okay too, this spring I put down about 100lb of Sunniland Palm 6-1-8 in my yard.  I also add some Langbeinite / Sulpomag / KMag to add extra potassium and magnesium for a few key palms.

If you can post a few photos of the palms, people here can make better recommendations.  For example, if the leaf tips are yellowing on a lot of fronds, then adding some Magnesium Sulfate granular is a good choice. 

[Kat67]

Hi!!! Was told by our lawn company (who doesn’t do a good job) that our Sylvester was deficient in potassium. So not sure they really know it’s specifically potassium or not (picture added), how is the best way to fertilize when I have a layer of landscape paper and rock down? Will granular get through this? I do have jobe spikes to put in but haven’t done it yet. Also has a drip line at the base of the tree but only watering lawn twice a week right now. 
 

TIA!!! 
I’m in the Florida panhandle. 

[sonoranfans]

1 hour ago, Kat67 said:

Hi!!! Was told by our lawn company (who doesn’t do a good job) that our Sylvester was deficient in potassium. So not sure they really know it’s specifically potassium or not (picture added), how is the best way to fertilize when I have a layer of landscape paper and rock down? Will granular get through this? I do have jobe spikes to put in but haven’t done it yet. Also has a drip line at the base of the tree but only watering lawn twice a week right now. 
 

TIA!!! 
I’m in the Florida panhandle. 

Florida sandy soil potassium deficiency is almost guaranteed, its the #1 deficiency in all of florida.  If you have clay soil just fertilize with a good 8-2-12 palm fertilizer like palmgain or florikan and repeat according to the label.  The rock on top of sand is a problem as neither has any cation exchange so deficiencies will be hard to control.  Organic matter(compost) and clay have cation exchange.  I would never put stone on top of sand, unless the tree didnt need any micros.   

[sonoranfans]

On 4/26/2024 at 2:59 PM, SoTXPalmNovice said:

Hi there!  I just found this forum when searching for palm fertilizer.  I need to feed my Sylvester Palms, and want do know what’s best for them and for encouraging fruiting without damaging the lawn and flowers around the trees.  Your suggestions are much appreciated.  
My palms have 2-3’ trunks with gorgeous fronds, mostly.  Some are yellowing/browning on the lower limbs. 
I use LeafGuard on the fronds to protect from cold and plan to use it to protect from the heat, winds, and over drying.  What else can I do to make my trees happy and healthy? 
 

I am not familiar with LeafGuard but your Silvestris needs no protection from heat, they take arizona heat fine 110F plus.  As far as coating the leaf with a film, it might cause overheating of the plant if you clog the stomata.  Palms and plants cool themselves by transpiring water vapor through the stomata.   Its especially important in hot sun where the cooling is needed to overcome the heat generated by chlorophyll synthesis.  If you dont allow freon to evaporate in your AC you get no cooling, same for the plants in hot sun if you have clogged stomata.  As far as cold protection, I cant imagine a sylvestris needs cold protection in 9B corpus christii as sylvestris is good to 9a.

[Merlyn]

@Kat67 as Tom said, potassium is a really common deficiency in Florida.  The sandy soils have a lot of Phosphorus, so that's not generally needed.  An 8-2-12 ratio was experimentally determined to be the optimum for palms in FL, ones like PalmGain and Florikan are the best options.  Dosing is 1.5lb of 8-2-12 for every 100sqft canopy, 4x per year.  For a 12' diameter sylvestris, that's 6*6*3.14 = 113sqft.  So roughly 1.7lb of 8-2-12 is about right.  You could also use about 2.5lb of Sunniland Palm 6-1-8, since it is lower concentration.  These are just guidelines, not an absolute rule.  Granular will dissolve through the rock and weed mesh.  There's a chance it'll discolor the white rock, since Manganese and Iron in the fertilizer do turn brownish.  I'm not sure how to guess if it will or will not affect the rock.

As far as telling deficiencies, here's my cheat sheet of visible signs:

• Nitrogen - Older fronds turn light green uniformly, new fronds remain dark green until deficiency is really severe
• Potassium - Older fronds get translucent yellow/orange or dead spots on leaves, especially at the tips. Caryota and Arenga get random splotched dead spots in leaves. Sometimes tips are curled or frizzled. Always starts at tips of oldest leaves, moving upwards
• Magnesium -Yellow ends on oldest leaves first, transitions to solid green at the base of each leaf. Does not cause leaf tip necrosis until really severe.
• Iron - Many times caused by overly mucky soil and root rot. Starts with new spear leaves with yellow-green or even white, possibly with spots of green. EDDHA works up to pH of 9, 3-5oz per 100sqft
• Manganese - Lengthwise necrotic streaks in NEW leaves with dead and curled leaf tips. Similar to bands showing Magnesium deficiency. Mn is NOT mobile, so it can't be stolen from old leaves.
• Boron - Bent or necrotic or distorted leaf tips, distorted or bent spear, bands of dead spots on new fans, spears that won't fully open, stunted fronds
• Water - Underwatering brown at the edges first, later followed by yellowing of the whole leaf. Overwatering can be drooping fronds turning yellowish and losing color
• Calcium – New leaves are stunted and necrotic, eventually growing only petiole stubs. Deficiency is rare. High pH from adding calcium can induce Magnesium, Manganese, Iron and Boron deficiencies.
• Dolomitic Lime or Azomite - Magnesium Carbonate – reduces acidity/raises pH – slower release and adds Magnesium, helps avoid Potassium deficiencies in Cuban Copernicias. 5Lb per palm on full-size Copernicias and a bit less on Kentiopsis Oliviformis
• Garden Lime - Calcium Carbonate – fast release but works well. 5Lb per palm on full-size Copernicias and a bit less on Kentiopsis Oliviformis
• Sulfur - Elemental sulfur powder or prills reduces pH, 1/2 ounce per cubic foot in sandy soils
• Sunburn - Orange/Red/Brown streaks on surfaces facing the point of hottest sun, typically the worst case is around 1-4pm. Sun tolerant species will adapt and grow out of it. Shade loving species may never adapt.

[Merlyn]

@Kat67 I forgot to mention, but Magnesium deficiency is really common in Phoenix palms too.  The most obvious sign is yellowed tips on the older fronds.  Your palm is "overpruned," meaning that too many of the older fronds have been cut off early.  Usually you want to leave the fronds to grow out and not cut anything that's above horizontal.  Fresh cuts in live tissue are a good entry for pathogens like fungi and bacteria.  That said, I prune some palms early for cosmetic or clearance reasons.  And some people prefer the "shuttlecock" cut for cosmetic reasons.  Early cuts can make nutrient deficiencies worse, as the palm pulls back nutrients from old fronds to grow new leaves.  You can replace that loss with extra fertilizer.

Here's a classic photo of Magnesium deficiency in a Phoenix Roebellini (Pygmy Date Palm):

[Kat67]

On 4/30/2024 at 4:21 PM, Merlyn said:

@Kat67 as Tom said, potassium is a really common deficiency in Florida.  The sandy soils have a lot of Phosphorus, so that's not generally needed.  An 8-2-12 ratio was experimentally determined to be the optimum for palms in FL, ones like PalmGain and Florikan are the best options.  Dosing is 1.5lb of 8-2-12 for every 100sqft canopy, 4x per year.  For a 12' diameter sylvestris, that's 6*6*3.14 = 113sqft.  So roughly 1.7lb of 8-2-12 is about right.  You could also use about 2.5lb of Sunniland Palm 6-1-8, since it is lower concentration.  These are just guidelines, not an absolute rule.  Granular will dissolve through the rock and weed mesh.  There's a chance it'll discolor the white rock, since Manganese and Iron in the fertilizer do turn brownish.  I'm not sure how to guess if it will or will not affect the rock.

As far as telling deficiencies, here's my cheat sheet of visible signs:

• Nitrogen - Older fronds turn light green uniformly, new fronds remain dark green until deficiency is really severe
• Potassium - Older fronds get translucent yellow/orange or dead spots on leaves, especially at the tips. Caryota and Arenga get random splotched dead spots in leaves. Sometimes tips are curled or frizzled. Always starts at tips of oldest leaves, moving upwards
• Magnesium -Yellow ends on oldest leaves first, transitions to solid green at the base of each leaf. Does not cause leaf tip necrosis until really severe.
• Iron - Many times caused by overly mucky soil and root rot. Starts with new spear leaves with yellow-green or even white, possibly with spots of green. EDDHA works up to pH of 9, 3-5oz per 100sqft
• Manganese - Lengthwise necrotic streaks in NEW leaves with dead and curled leaf tips. Similar to bands showing Magnesium deficiency. Mn is NOT mobile, so it can't be stolen from old leaves.
• Boron - Bent or necrotic or distorted leaf tips, distorted or bent spear, bands of dead spots on new fans, spears that won't fully open, stunted fronds
• Water - Underwatering brown at the edges first, later followed by yellowing of the whole leaf. Overwatering can be drooping fronds turning yellowish and losing color
• Calcium – New leaves are stunted and necrotic, eventually growing only petiole stubs. Deficiency is rare. High pH from adding calcium can induce Magnesium, Manganese, Iron and Boron deficiencies.
• Dolomitic Lime or Azomite - Magnesium Carbonate – reduces acidity/raises pH – slower release and adds Magnesium, helps avoid Potassium deficiencies in Cuban Copernicias. 5Lb per palm on full-size Copernicias and a bit less on Kentiopsis Oliviformis
• Garden Lime - Calcium Carbonate – fast release but works well. 5Lb per palm on full-size Copernicias and a bit less on Kentiopsis Oliviformis
• Sulfur - Elemental sulfur powder or prills reduces pH, 1/2 ounce per cubic foot in sandy soils
• Sunburn - Orange/Red/Brown streaks on surfaces facing the point of hottest sun, typically the worst case is around 1-4pm. Sun tolerant species will adapt and grow out of it. Shade loving species may never adapt.

 

[Kat67]

Wow thank you so much! This is very helpful. I will check out these fertilizers. I think I am trimming to early. Even the middle fruit like things are turning brown. Thank you again!!!