Dypsis Prestoniana and Carlsmithii planting

[PalmSam]

Hi All,

I am looking for some advise on planting a Dypsis Prestoniana and Carlsmithii. I've read that since they're heeled palms it's best to plant them on a raised mound as they will pull themselves down.

My garden has only about 10–15 cm of topsoil, and below that it's really dense, heavy clay which is very hard to dig, even when wet.

Does anyone know how high I should raise the mound for these palms? Also, does the carlsmithii need to be raised as much as the prestoniana? I've seen suggestions that it might not need to be raised quite as much.

Thanks!

[Cannonball]

Carl Smithii, in my opinion won't need to be as mounded as Prestoniana for the purposes of the heel complications.  However if the soil is as you say it is with reference to the clay, then I would definitely be mounding the garden beds up as far as is practicable. 

Palms, and most plants for that matter, will do far better if they have a good start in life. If they have a few years of unimpeded root growth then they will deal with hitting the clay much better.

Lots and lots of organic matter and Potassium Nitrate. Humic and fulvic acids, vermicast etc.

[PalmSam]

On 5/9/2025 at 10:51 AM, Cannonball said:

Carl Smithii, in my opinion won't need to be as mounded as Prestoniana for the purposes of the heel complications.  However if the soil is as you say it is with reference to the clay, then I would definitely be mounding the garden beds up as far as is practicable. 

Palms, and most plants for that matter, will do far better if they have a good start in life. If they have a few years of unimpeded root growth then they will deal with hitting the clay much better.

Lots and lots of organic matter and Potassium Nitrate. Humic and fulvic acids, vermicast etc.

Thanks so much, I'll make sure to do that then!

[PalmSam]

On 5/9/2025 at 10:51 AM, Cannonball said:

Carl Smithii, in my opinion won't need to be as mounded as Prestoniana for the purposes of the heel complications.  However if the soil is as you say it is with reference to the clay, then I would definitely be mounding the garden beds up as far as is practicable. 

Palms, and most plants for that matter, will do far better if they have a good start in life. If they have a few years of unimpeded root growth then they will deal with hitting the clay much better.

Lots and lots of organic matter and Potassium Nitrate. Humic and fulvic acids, vermicast etc.

Also, If I plant a 5–7 gallon sized Prestoniana that's about 6–7 feet tall, do I still need to mound it like I would a seedling? Has most of its heel root growth already happened by that point?

[Cannonball]

Thats a good point, perhaps it's important to think about the situation its to be introduced in to also.

Is its ability to pull itself down compromised by the clay under base ?

Can you still see the heel of the palm in the pot, if so then ?

[Bags]

My yard was very hard sand stone with no topsoil. I added 12”-18” of topsoil and planted almost everything from less than 5 gallon pots. Most were 1 gallon or 4” pots from Floribunda. This is my 3rd Prestoniana in the same spot. The first two were duds and died. This one blew up. I would have enough topsoil to avoid digging into the clay and not worry too much about mounding and the heel height. Healthy plants don’t seem to care. 

[happypalms]

There is a saying a $2 hole for a $200 plant, or a $200 hole for a $2 plant. Many various methods abound for planting, I have both palms you mentioned recently planted, just dig your planting hole as large as you can remove the soil amend with your favourite good quality soil filling the hole up completely, mix it in then remove the amount of soil required for the pot size you wish to plant, test the depth of the hole placing your palm in the container and checking if you need to remove or add to get level of the bottom of your palm stem you can go a couple cms above the stem level but not too much. Then plant and back fill around your palm tucking in the soil. Then water with seaweed extract for vitamin B stress relief. 

[PalmSam]

Thanks for all the advice everyone!