Dicksonia antarctica (Dicksonia antarctica) Soil conditions.

[Dave Brown]

I think there are no prizes for guessing the Dicksonia antarctica like woodland soil which is moisture retentive but fairly friable in nature. However it came as a bit of a shock that Melissa's grow so well in a sandy soil, almost pure sand further down. I am not so fortunate and have a plastacine clay suitable for a pottery or making models. When I planted my Dicksonia antarctica in spring 2007 it was already rooted in a pot with a healthy mat of tangled roots. I dug out a hole about 45cm (18in) diameter and threw the clay away, backfilled with a mixture of peat and bark compost.

It grew reasonably well over summer, but was rather crowded out by the Colocasia Mammoth growing next to it

In spring 2008 I decided to dig out another section of clay near to the pond to grow Bizzy Lizzys. but what I found was the Dicksonia antarctica had an extensive set of roots into the peat/bark, but had just stopped dead at the clay. It may as well have been planted in a pot Here you can see the roots just will not travel in or through the clay

The whole bed was mulched with a bark/gravel mixture to retain moisture through summer of 2008.

This year I decided to widen the border digging out more of plastacine to allow it more root room. What I discovered was the roots were happy in the mulch which was over the clay but did not penetrate the clay itself, so I had a thin vaneer of roots over the barren clay. I dug down to about 15inches, and dug out under the surface mat of roots until I reached the original planting hole. I seem to be doing a lot of under pinning type work recently, what with the Agave falling over I added a gravel/sand mixture to the base of the hole, and backfilled with a peat/bark/gravel mixure, pushing the root mat down a couple of inches to avoid drying out.

Hopefully now, with a bit more root room, I can start to compete with Melissa's impressive growth rates

If you have a heavy clay soil do not expect the Dicksonia antarctica to root into it, so unless you are prepared to dig out a 3m (10ft) area.Then I would recommend a raised bed

[themes]

I have championed raised beds for them with very few feedback from others . You can adjust the soil to your liking. I plant mine in 50% bark to 50% soil. My soil being acidic and high in composted leaf mulch. It is very rich anyway. They have done so much better than last year. I experimented further..

I dug really deep down then created a raised bed. Below the raised bed I put an old compost bag with a few holes, so as to retain a bit more moisture (like I did when I created my bog area) I have had some new fronds appear and they are very big. Keep the old fronds on, to retain more moisture.

[carolpz]

Mine grows very well in clay with no feeding at all and has an extremely extensive root system. When I first planted it out I didn't really give much thought to the soil conditions, only the shade. The nearby Cyathea medullaris has also grown an extensive root system. So thick are the two combined that I'm unable to plant anything else and have to rely on Woodwardia to root itself around them which it does with great enthusiasm.

[Dave Brown]

Carol, when you say Clay can you mould it into shapes and animals or does it fall apart. The clay I have here the Romans used for pots and roof tiles, just a shame they didn't dig it all out.

As you can see from the pics in my previous post, the Dicksonia antarctica has made no attempt to root into the clay. By digging a hole and planting it, I may as well have planted it still in it's pot.

[becky]

looks like you have done a great job dave mine is in very sandy soil, iv mixed in lots of bark, they seem to be doing very well, but , i love all the layers of leaves on yours it looks great, oh and dave can you send me some of that clay my bailey would love making men out of that

[Linden]

Those are amazing pictures Dave, just goes to show how important soil is for these plants. If times get tough, you could always become a potter - looks like you have a natural talent making figurines

[simon]

So, what are your thoughts about what is happening here, Dave. Do you think the roots are phylically not strong enough to penetrate the clay or do they penetrate but quickly shrivel and die because they don't like the conditions?

[Dave Brown]

So, what are your thoughts about what is happening here, Dave. Do you think the roots are phylically not strong enough to penetrate the clay or do they penetrate but quickly shrivel and die because they don't like the conditions?

I think the roots are strong enough, but when this stuff gets compacted there is no air. The roots tend not to rot even if the Dicksonia antarctica dies but I found no evidence of roots in the clay. I think a lot of high water plants like regular watering but prefer soil that has air. The fact that the roots happily went through the mulch but not into the clay means they really don't like it. Like bamboo wil not travel into or through water, Dicksonia antarctica seems to not travel through my clay.

Carolpz, maybe your clay is not as heavy, or has a more crumbly texture.

Becky you're lucky having a workable soil. This is why I am still planting out in July every year. I can't get onto the soil until at least end of March

Linden, perhaps I'll make some Gnomes. Kentish Gnomes for sale

[carolpz]

It's the kind with which you can make pottery when it's wet and can make bricks when it's dry.

[Imran Khalid]

IIf you have a heavy clay soil do not expect the Dicksonia antarctica to root into it, so unless you are prepared to dig out a 3m (10ft) area.Then I would recommend a raised bed

Dave you have to be careful when making conclusive statements like this. You're basing your opinion on just one Dicksonia antarctica, and a small one too.

What's you statistical proof? Have you done trials on several plants?

Carolpz is already contradicting your claim for one, I'd suggest you gather more data before making definitive statements.

[Linden]

Just looking back at your pictures Dave, it's amazing how much it grew even though the roots couldn't spread. I've had one in a pot since we bought it last year and I've been nervous about putting it in the ground (I have a bit of a hang-up about committing things to terra firma for some reason ) but it's going in today now I've seen your pix. I have a raised bed that's under some old conifers, lots of old needles and leaves, gets a little sun too, I think it's the ideal place. I MUST COMMIT!

[MonkeyDavid]

I've always been told to feed & water the crown & trunk as this is where it's roots are, the roots in the ground are just anchoring roots, is this not the case? does it also/instead get its nutrients from the soil?

[Dave Brown]

I've always been told to feed & water the crown & trunk as this is where it's roots are, the roots in the ground are just anchoring roots, is this not the case? does it also/instead get its nutrients from the soil?

Troppoz said plant them deep to get the most lush crown, so it ssems they get a more balalnced feed form roots in the ground. Some I have seen have a dense mat of roots about 4 to 6 feet in diameter.

Carol, I don't undersatnd you're saying yours happily root into clay. Mine must just be lazy then, unless it is the clay composition it doesn't like. Is yours Redish like in Devon. It is a brown/grey colour here

[simon]

Maybe yours is colour prejudiced, Dave .

They certainly do need roots in the ground in order to thrive. Can you imagine a plant surviving in the wild if it couldn't draw water or nutrition from the one place where it is abundant? Although rain water will be absorbed directly from fibrous roots in the trunk and a few leaves caught in the crown would decay and thier nuntrients would be absorbed, it would not be enough to sustain life over the long term. Evolution has a habit of exploiting the easy options.

The application of feed to the crown is only meant as a stop-gap until the fern has established itself in the ground but they don't like a dry trunk, so this should be regularly soaked along with the soil around it.

[carolpz]

Dave, our clay soil is almost black, certainly very dark. It's on the edge of a large granite pluton and is fairly neutral as far as acidity goes. I'ts known for being quite fertile so perhaps that's the difference. I also bought mine as a 'log' so it already had plenty of rhizome. My only problem is the root system is so dense I can't even get a gardening fork through it.