Cycas multipinnata

[96720]

What growing conditions do these like mine always looks terrible!!

[aussiearoids]

Mine has thrived planted out in well drained red volcanic soil in the wet tropics.

Habitat is limestone based soil on hills.

Mature now and have male & female and got big batch of seeds. 

 

[Merlyn]

Moist, part shade, fairly rich soil, and any "palm special" type fertilizer should do well.  The only thing that mine don't like is torrential rain for days on end...and frost.    I'm not sure on the exact reason yours is so splotchy, it could be a combination of too little water (or root rot from being too wet), and lack of potassium or Mg/Mn.  I had a few Cycas and Encephalartos go spotty like that when they flushed before I'd fertilized them.  What are you currently doing for sun, water and fertilizer?

[96720]

They are in the greenhouse pretty shady they don’t have root rot I just repotted it I don’t fertilize so that might be the problem 

[Merlyn]

Yep, I have fertilized all my cycads 4x per year just like my palms.  In the ground they get "palm special."  In pots they get Osmocote plus some extra Mn and Mg Sulfate.  I wondered about earlier comments about *not* fertilizing cycads.  I thought maybe it was something in AZ vs FL climate.  But it seems to me that cycads need fertilizer anyway.  BUT keep in mind I only have about 3 or 4 years growings cycads, so little experience overall.

[PalmsandLiszt]

19 hours ago, 96720 said:

What growing conditions do these like mine always looks terrible!!

Possibly too much water. I understand excess water inhibits the uptake of manganese, and this element can't be transported and recycled by the plant from old leaves. I get similar (but less extreme) striations on my C. debaoensis. You medium looks a bit dark and stolid; I'd try to make it less dense and more airy. I have a C. petraea that had similar striations in the nursery pot (with their media) but have now gone when repotted into a well-draining medium.
I also wonder whether some of the browning is just sunburn; this cycad grows on misty Chinese hills; in Arizona you probably want to position it very carefully and protect it from full sun, or even half-full sun.

[GeneAZ]

That's a soluble salt problem that we all have here in the low desert.  The TDS of tap water in all of Maricopa county is consistently 450 to 518 ppm.  Over time, watering containers with this salt level creates even higher TDS of the container soil.  Flushing helps a lot, but washes away nutrients.  The tap water pH is 7.60 to 7.75 which locks out a lot of essential elements.  So you've got to lower that pH and the nutrition will become available to your plants for absorption.

My current best solution is to get a vat and fill with tap water; do a TDS test with a cheap 20-dollar TDS meter; do a pH test with a high quality pH meter; then treat the pH with sodium bisulfate (AKA dry acid) purchased from Leslie Pools store.  Gradually add the sodium bisulfate to the water and re-measure the pH each time you do.  Keep adding the bisulfate and rechecking until you get pH readings of 6.o.  Then water with this solution as your regular watering source.  You will no longer have any salt related leaf symptoms; such as crispy tips, brown edges, yellow edges, crinkled leaves.

If you are going to add liquid feed to this water, I suggest you add the appropriate fertilizer to the untreated water at the start, then check the pH and TDS and adjust with the bisulfate at that point until the desired pH is met.

This buffer agent sodium bisulfate has been by far superior to pH-Down products that I've tried over the last 30 years.  Also it is much cheaper!!

I also have my sister in San Diego using this buffer since her tap water is identical to mine in terms of the pH and TDS.

 

Edited January 17, 2023 by GeneAZ

[96720]

I water my tropical in the greenhouse with ro water I think it is probably a fertilizer problem because I don’t fertilize!

[Merlyn]

3 hours ago, 96720 said:

I water my tropical in the greenhouse with ro water I think it is probably a fertilizer problem because I don’t fertilize!

RO water should be slightly acidic, theoretically it comes out at 7 but might shift lower with exposure to air.  I don't know what RO water does in pots.