Syagrus romanzoffiana diagnosis help

[Clem64]

Hello all, I am turning to all you palm experts for help identifying what is going on with my queen palm… They are planted in the Basque Country in a zone 9b/10a about 300 ft from the ocean, it very rarely goes to freezing temperatures here, and if it does, its for a couple of hours max before temps go up when the sun rises… so nothing the queen palm can’t handle. It is very humid here, winters are VERY rainy, it doesn’t rain all the time, but when it does, it rains a lot! (over 60 inches of rain in a year) For the health of my queen palms, ill let you take a look at the pictures, I find them very yellow/pale green almost translucent. I’ve been giving them palm fertilizer (maybe not enough) that I can find here (N.P.K. 5-3-7 + 2 MgO). From what I’ve gathered, queen palm are quite hungry in terms of nutrients and this fertilizer might not be enough for its needs? Or maybe a fungus?

PS: I have another queen palm about 100ft away that has no problem…

Thank you all very much for your help!

[Johnny Palmseed]

The fertilizer seems like a good blend for palms but the pictures look like a deficiency in Manganese(Mn) and/or Potassium(K). If the discoloration is more on the newer leaves, it would indicate Mn. But if it is more on the older leaves that would indicate K. If you do get a lot of rainfall, that can contribute to a deficiency especially if your soil is sandy.

[Harry’s Palms]

That looks like it could use a good fertilizer . If you can get some palm specific fertilizer online it would help , but it will take a while to show on the palm. The fronds that are present now will not change , only the new growth. If you have dry periods between rain events they must be watered frequently to look their best , they are very thirsty palms . I can’t see the soil around the base . If you take a claw and break up the soil and mix in some top soil garden mix at least an inch deep and then top with wood chips , the palm can more easily get water and nutrients . That also takes time to have an effect. I do my garden at least once a year , usually Spring time . Harry

When I fertilize or not , I rake the wood chips to one side and work in fresh garden soil with a claw about once a year . The loose soil absorbs water much better . Harry

[Merlyn]

The fertilizer ratio seems reasonable, I'd also agree with the potassium & manganese deficiency.  It could also be a bit of Boron deficiency, as it can also cause distorted new fronds.  Mulch around the palm will help with boron deficiency, the mulch will essentially slow-release boron and other nutrients as it degrades. 

I didn't see a sign of fungus, though some leaf spots could be a "cosmetic" leaf spot type.  To rule out a fungus, do the new spears look clean and green?  Sometimes a bud rot can damage the new spears as they are growing.  If you can check the new spears and/or post a photo that would help.

One other possibility is that the palm closest to the building is planted in "builder's sand."  At least here in the US the foundations are poured on fine sand that's sometimes hydrophobic, and devoid of nutrients.  That doesn't mean you can't grow a palm there, it just means that it may need more fertilizer than normal and stuff like mulch would help a lot.

[Clem64]

Thank you all for your suggestions, I did lean towards more of a Potassium deficiency from what I've been able to look up. For the watering, i doubt it coud be underwatered as i've said the rain fall from November to April is heavy, the ground doesnt dry between showers and in the summer time I make sure to water. As for the soil, there is no "builder's sand" in the soil, its quite heavy soil in what used to be farm lands and was used in the past 60 years to grow vegetables.  I've attached more pictures, the new spears dont have spots on them, i find them to be too much on the light green side though. The fond you can see in the 3rd picture of my first post did come out with the top damaged as seen in the picture, new fonds have come out without damage. Unfortunatly i'm having trouble finding better palm specific fertilizers other than what i have. Would a fertilizer 30% K2O - 10% MgO - 42% SO3 be a good solution to work on the potassium deficiency? What type of mulch would help with the Boron? Also can't seem to find any fertilizer with Manganese... I might be in the US in a couple of months so i'll probably try and bring back some palm specific fertilizer if anyone has a specific one in mind that could be worth bringing back... 

 

 

 

 

 

[Merlyn]

The new fronds and spear look clean, so probably no issues with Boron deficiency or a crown rot fungus.  The soil sounds like it should be fine, and the picture looks like a Queen would like the rich mulch layer.  Here's my notes on deficiencies, for reference:

• 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.

Since Manganese is *not* mobile from old fronds, I'd rule that out as a cause.  You'd see it first in the new fronds, which look good.  The smaller palms in the picture show typical leaf tip yellowing of Magnesium deficiencies, common and looks fairly mild.  The translucent and black spots with dead leaf tips is typical Potassium deficiency.  It may be that they just want more of your current fertilizer.  How much are you giving them, and how often?  You could also consider adding KMag or SulPoMag or Langbeinite, all names for the same stuff. 

[Harry’s Palms]

@Merlyn very good info ! Thank you. Fortunately , where I am, I just have to water them and amend the soil every year . I only had one that just wouldn’t look good so I cut it down. Harry