Did I just kill a 200-million-year-old tree?
January 28, 2010 6:47 PM   Subscribe

Can my very droopy and sad-looking Wollemi Pine be saved? He started out perky, but now he looks like Charlie Brown's Christmas tree. Or is this just what a 200-million-year-old gymnosperm looks like?

My husband and I bought a Wollemi Pine from a Sydney nursery in September. The instructions we got indicated that the tree would be happy in a pot and out of direct sun, so we put him in a large pot near our front door. Here's what he looked like then.

The location is sheltered and it gets only indirect sun. We read that overwatering can be a problem, so we've tried to limit watering to times when the pot soil feels dry. (No more than once every week or two.)

We had an initial period of lots of growth, but now our little tree is looking very droopy. Here's what he looks like as of today. You can see all the new growth along his branches, but they're *very* droopy. Some of the lower branches are slightly brown and dry looking.

I've been searching the Internet but all the advice I read is conflicting. Should we move the pot into the sun? Is it the hot humid weather we've been having? Are we over or underwatering? Could the potting soil we used (just normal potting soil with some compost) be inhospitable to the species? Could the pot itself be leeching something into the soil that is hurting the tree? (It's just a normal pot that we picked up secondhand.) Or is this actually just normal growth, and the branches are drooping because of the additional length?

I emailed the nursery today, but I thought I'd throw it out to the MeFites to see if we have any l33t gardeners who can chime in...
posted by web-goddess to Home & Garden (25 answers total)
I didn't realize this had been released for cultivation and sale, but it's good to see the proceeds go to preserving the wild population. When I visited Kew in 2006, they had one specimen, about 4' tall, in a 6' cage. We joked that the tree must clearly have been very very bad. You might also look at cultivation tips for the Norfolk Island Pine and others in the Auracaria family.
posted by Emperor SnooKloze at 7:00 PM on January 28, 2010

Best answer: Check with the nursery, but to my eye that tree's roots look unhappy. I suspect that the potting mix at the bottom of the pot has got compacted and anaerobic and sludgy and rot-prone, possibly because there was always too much organic matter and not enough sand in it.

He's a rainforest tree, so he'll be expecting to grow downward into a fairly poor sandy soil and having his organic goodness continually leached downward from the top of the soil column. If he were mine, I'd be re-potting him into a pot about one and a half times as deep, with maybe 50mm of gravel at the bottom, then maybe 150mm of coarse sand, then a mix of 1/3 potting mix, 1/3 perlite and 1/3 fine white sand with the tree in it, then 30mm of compost over the top as a mulch.

I'd also drip-water him rather than relying on a weekly or biweekly flood. Rainforest floor generally stays fairly damp under the leaf litter layer; it doesn't often dry right up.
posted by flabdablet at 7:09 PM on January 28, 2010

Yeah, I can't help but think that the plant looks thirsty. It doesn't want to sit in a puddle, but as long as the potting medium has good drainage (potting soil + a hole at the bottom), it's unlikely you'll drown it with weekly watering. It literally comes from the rainforest, so it should be good with humidity. Flabdablet's drip-irrigation advice is good.

Sometimes plants will just droop due to heat, and as long as you don't let them dry out entirely, they perk up when the weather gets better.

I find it unlikely that the potting mix at the bottom of the pot would become so icky and compacted in just a few months, though. The pot does look a little bit big for the plant (I too frequently repot plants into pots that are way too big, and I find that they struggle with the extra room), but it seems to be growing at a healthy clip, so the plant will resolve that soon enough.

The good news is: Droopy or not, you're definitely not killing it. I've had plants that looked way more like they were approaching death's door. Good job!
posted by purpleclover at 7:17 PM on January 28, 2010

Best answer: That kind of wilting can be a product of overwatering (and the subsequent lack of oxygen in the soil) or underwatering, or a lack of the roots' ability to absorb moisture from the soil due to a root issue such as a fungal pathogen. Symptoms look the same, really. You might want to excavate a few of the roots and see if they seem bright and turgid, or dark and gooey, or fuzzy, or spongy, or basically not like nice happy plant tissue. This can be difficult to determine because of the dizzying array of plants' physiological characteristics, but you can usually get an idea. Hot and humid can make certain fungi very happy, especially if the plant is stressed. Certain fungi on roots are good, but if you can scratch the bark on the roots and the tissue beneath doesn't look bright, that's a bad sign. It's hard to explain.
The "normal potting soil with some compost", does that mean that you mixed in compost with potting soil? Depending on they type of compost, that could affect the soil in a beneficial or detrimental way. It could be too "hot", or have an alkaline ph, or make the soil anaerobic. I don't know what Wollemi pines require in the way of ph.
I'll tell you what: most any plant will do fairly well in a moderately porous soil that gives it oxygen and gas exchange and drainage, that is somewhat moist (kept from being sodden and not allowed to get very dry), has a neutral ph, and enough organic matter to break down into components and fertilize the plant.
The tree looks pretty poor. Does the bark on the branchlets look a little shrivelly? Most species have turgid bark on twigs and branchlets.

It's doubtful that anything is leaching (it's leaching) from the pottery, but is it glazed on the inside? Have you fertilized it at all? Over-fertilized?

I don't want to keep on writing. But good luck!
posted by Red Loop at 7:21 PM on January 28, 2010

Oh, and when I said I wouldn't rely on the weekly or bi-weekly flood, I didn't mean that I would never flood him. Even with a drip in place, he will need some top-watering to leach goodness out of his mulch layer. However, given that Sydney's rainfall patterns are probably fairly similar to those of his native territory, you could probably rely on natural rainfall to do the flooding. Just make sure he's not sheltered from it by one of your eaves.

Thinking of mulch layers, you should maintain his by throwing a handful of leaves into his pot every now and again. If you drink real coffee or real tea, just keep chucking your coffee grounds and/or old tea leaves in there; they're close enough to forest-floor leaf litter. You can't really overdo surface mulch for a rainforest tree.

Lose the ornamental rocks, as they will discourage you from adding stuff that doesn't look as nice as they do.
posted by flabdablet at 7:37 PM on January 28, 2010

Pines generally like a slightly acidic growing medium.
posted by torquemaniac at 7:55 PM on January 28, 2010

Response by poster: My husband would like me to clarify that some of the lower branches aren't just brown; they're "completely dead." I didn't notice that when I took the picture.

Thanks to everyone for the advice... though it's sorta just as contradictory as the stuff I was getting from googling. I'm taking the tip of looking at Norfolk Island Pine care to see if that clarifies anything.
posted by web-goddess at 8:40 PM on January 28, 2010

You could try asking here: http://www.au.gardenweb.com/forums/oznative/

I remeber them being a really good forum many, many years ago, though they currently seem to be having some technical difficulties.
posted by kjs4 at 10:42 PM on January 28, 2010

Torquemaniac, it's not actually a pine, though it is a gymnosperm (in the Araucariaceae family).
Web-goddess, I'm sure you saw this page on the WollemiPine.com site, which indicates it can grow in full sun or part shade and likes a neutral to slightly acidic soil. Just a few more suggestions: look very closely at the branches that are still alive, maybe using a lens if you have one, and look for any tiny mites or insects, or any tiny fungal structures. A trick to find mites is holding a piece of white paper under a twig and flicking the twig, looking for specks on the paper. If you see specks and can smudge them with your finger, you probably have mites.
posted by Red Loop at 4:27 AM on January 29, 2010

There's no way to know how much you should water if you aren't feeling the soil. When the top 2-3 inches around the root ball dry out, then you water thoroughly until water comes out the bottom of the pot. This is what I recommend for nearly every plant in a container, and it is what is recommended by wollemipine.com.
posted by oneirodynia at 10:20 PM on January 29, 2010

Response by poster: Thanks, everyone. As I said in the initial post, we have been feeling the soil before watering. We visited a local garden center on Sunday and showed the expert there the photos. His thought was that we might have put it into too large a pot, and the roots might be rotting. (Which would explain how we may have overwatered even if the top soil felt wet.) We also found a bug case near the tip of the tree, so we think insects may also be a factor.

For now what we've done is move the pot from the front door to the side of the house in the shade of a large palm. So he's protected from full sun, but he'll definitely get more light. (We have a potted bay tree and a potted lime that are doing really well in that location.) We also rotated him, since it looked like the drooping was much more on the side away from the little light he was getting. I've given him a spray of Pyrethrum in case of any lingering bugs. We're going to leave him there for a week or two and see how he goes. We're also looking into getting a device to measure moisture levels, so we'll be able to see if it really is wet down inside the pot (before we dig him up for another transplant).

Will keep you posted...
posted by web-goddess at 11:36 PM on January 31, 2010

Response by poster: "...how we may have overwatered even if the top soil felt DRY," I meant.
posted by web-goddess at 11:39 PM on January 31, 2010

We're also looking into getting a device to measure moisture levels

Keep a bamboo kebab skewer stuck into the soil at all times, to roughly the depth you think the bottom of the root ball is at. You'll get a good-enough idea of soil moisture just by pulling it out and feeling the tip.
posted by flabdablet at 1:25 AM on February 1, 2010

Response by poster: It turns out that the garden center guy was right. My husband dug the Wollemi Pine out of his pot and could tell immediately that the roots were in a sorry state. Wet and rotten. We've moved him into a much smaller pot and we're hoping now that the roots can dry out and he can revive. We bought a wireless soil moisture meter and stuck it in there so we can tell definitively if he needs water or not.

I've given a best answer to flabdablet and Red Loop for corrently guessing it was a root issue. Thanks!
posted by web-goddess at 8:41 PM on February 4, 2010

What I totally fail to see is a necessary connection between over-wet roots and the size of the pot. I've seen that "pot too big" advice in lots of places and never understood the rationale.

If the theory is that the plant is supposed to be sucking up the excess water, and it can't do that if the pot's too big: I think that's terrible system design. It seems to me that having spare soil around the roots could only ever be a good thing, provided it was the right kind of soil and not something subject to collapsing and sogginess.

If the only thing preventing sogginess is that there's so little soil available that the plant can suck it dry before it rots, I'm as sure as I can be that it's soil quality that needs attention, not quantity.
posted by flabdablet at 10:19 PM on February 4, 2010

Response by poster: I don't get it either, but that's what he said! Maybe it's particular to this type of tree. Perhaps the area where they survived had very little topsoil?

At any rate, here's what he looks like now...
posted by web-goddess at 8:01 PM on February 5, 2010

What he's in there looks very, very black. Did you wash off his roots and pot him into new mix, or just re-use the rot-riddled old stuff?
posted by flabdablet at 2:32 AM on February 6, 2010

Response by poster: Husband says he just put the same stuff, "but less of it." It's black because it's been raining for like 36 hours straight in Sydney, and everything (even the stuff that isn't exposed to the sky like the tree) is, as we say, "damp as."
posted by web-goddess at 2:39 AM on February 6, 2010

The same stuff as in fresh stuff of the same kind you put in the original pot, or the same stuff as in old stuff that came out of the old pot? Because if you're just re-using the very same soil that rotted his roots in the first place, the same root-rotting organism will still be abundantly living in it, and he will take much longer to get better even if the new pot improves his drainage somewhat.
posted by flabdablet at 4:25 AM on February 6, 2010

And also, if he's just growing in straight potting mix from a bag of supermarket potting mix, he is going to be far too wet for far too long. Supermarket potting mix is supposed to supply the organic component of topsoil, not substitute for it entirely; it doesn't have the grain structure needed to keep the soil from collapsing and becoming anaerobic when wet. If you're using supermarket potting mix, I strongly recommend mixing it 1:1:1 with sand and perlite.
posted by flabdablet at 4:28 AM on February 6, 2010

The growing medium which was used at the Toolara Nursery in Queensland was sourced from Susan River Soils and consisted of boiled/steamed bark and sand in about 2:1 ratio, This soil is very free draining and does not cake in the bottom of pots.

We have about 500 Wollemi Pines growing on our property near Childers Qld and imported about 10,000 to our Nursery in San Diego.

Our oldest trees in Childers are over 2m tall now and planted in full sun in red dirt. Each tree in the ground receives 16 liters of water every 4 days as well as natural rain.

At the propagation nursery the plants were watered every three days and received a liquid fertilizer and fungicide spray on alternate weeks.

As you have found out the potting soil sold in supermarkets is not very good quality. If you have to use it get Searles or a similar quality product and ammend it 50/50 with course perlite. We don't use sand with a bagged potting mix as it does nothing to improve the drainage as the potting is too fine and the sand just hold water by the capilliary action.

Hope the wollemi makes it


posted by Bruce@cycadcenter at 3:56 PM on February 6, 2010

Response by poster: Hi Bruce - wow, did you join just to answer my question? Thank you so much!

I have a big bag of vermiculite at home that I was using to mix in with some raised garden beds. Would it be okay to use that instead of perlite?
posted by web-goddess at 6:10 PM on February 7, 2010

Vermiculite is much softer than perlite, and the grains aren't rounded. The main reason for adding perlite and/or sand is to create a hard-to-crush skeleton for the soil so that as its organic components break down into humus it doesn't pack down into an anaerobic blob of glug (pardon the technical language). It doesn't take much weight of wet soil to make vermiculite pack down, which kind of defeats the purpose.

Perlite is great because although it's lightweight it's fairly rigid, and it's full of pores that tend to soak up semi-liquidized decaying organic stuff instead of letting it all work its way down into a foetid little pool at the bottom of the pot. It also wets more slowly than vermiculite, so after a quick flooding watering, the perlite will still be sponging up excess water from the surrounding soil for quite some time. This sucks air into the soil and encourages good drainage.

I like a mix of perlite, sand and organic stuff because the sand stops the organic stuff shifting too much and the perlite stops the sand. With some potting mixes, as Bruce points out, adding fine sand can sometimes make the mix drain worse, not better. Depends how chunky the potting mix is.

Non-clumping clay cat litter can also be quite a useful soil amendment. It works a lot like perlite as far as adding structure and sponging up and retaining excess water goes, but it's a fair bit heavier. It's also often fairly dusty and the dust tends to run to the bottom of the pot and make soggy mud there. Provided you've got a good deep layer of gravel in the bottom, though, most of that will run out.
posted by flabdablet at 1:57 AM on February 8, 2010

One of the other things I suspect is that the plants were grown in practically sterile conditions at the nursery in Toolara, as one of the very very few people who was able to visit the nursery we were required to change into sterile overalls and wash down boots etc all equipment was sterilised prior to entry and the potting mix being steamed/boiled was sterile.

My thoughts are that once the plants get out into the big wide world that they are subjected too any bugs, fungus etc found in potting soils etc.

I'm afraid from my experience that your Wollemi is a gonner.


posted by Bruce@cycadcenter at 11:40 AM on February 9, 2010

Response by poster: UPDATE: Bruce was right, and my little tree was a goner. He's pretty much dead now. Thanks to everyone who tried to help. I'm going to just think of the money I spent on it as a donation to Wollemi Pine preservation efforts.
posted by web-goddess at 8:57 PM on February 21, 2010

« Older Need guidance on moving pets from US to Ireland.   |   Supergroup Musicals? Newer »
This thread is closed to new comments.