Hawk Hill Orchids

DOGGY BARK GOODBYE! by Robert Hamilton, Hawk Hill Orchids

About this same time, Tom Perlite of Golden Gate Orchids, was testing a new bark product from New Zealand sold under the name Orchiata – www.besgrow.com

I had heard good things about this product from friends in Australia and New Zealand. We decided to purchase a pallet of bark from Tom. The bark came as a mixed lot with bags of both fine (#9) and medium (#5, aka “Power”). Orchiata is made from 100% New Zealand Pinus Radiata bark, a renewable product derived from tree farms. Orchiata advertises their bark goes through a special process which creates “a renewable high quality, stable, long lasting, toxin free, consistent growing substrate”.

They further claim their bark supports helpful organisms and suppresses pathogens. I have found it a harder, denser bark than fir bark and it wets nicely.

I decided to make a 100% switch to Orchiata. This year I have finally completely this task. All of my plants are in Orchiata bark and to say that I am pleased with their growing is an understatement! I would go so far as to say ecstatic. Orchiata is performing superbly and two of my colleagues who were skeptical at first have now switched to Orchiata bark. I have tried it straight, mixed with “red lava rock”, a rock from a local landscaping supply and with a bark, lava, charcoal blend. When supplementing bark with another material such as rock, one has to use care to select a material with the same size, so one does not fill up the “open space” of the mix.

For this last year’s potting, I have added a cup of oyster shell flour, a product sold to the poultry industry. This is a trick I learned from Jerry Rodder, a superb local grower and the patent holder for “Jerry’s Grow” fertilizer. A visit to Jerry’s greenhouse where he has “with” and “without” oyster is pretty convincing.

So far the bark has lasted two years with no signed of decay. Root growth is phenomenal. I have stopped using the #9 fine bark for mature plants and am using only the #5, Power. The pure bark mix and the bark with lava rock (of about the same size) both grow well. The lava adds weight to the pots which is useful in keeping pots from getting tipped when watering. Adding about a cup of oyster remains an experiment, but appears to be beneficial. The concept is oyster shell, which is virtually pure calcium carbonate, acts as a pH buffer helping to maintain the substrate at a constant pH. I have nixed using any charcoal whatsoever as it seems to offer no benefits. It has inconsistent size and is nasty stuff to work with. (Note: Andy Easton recommends gypsum for the same purposes and he finds it superior to oyster.)

After my change to Orchiata, I have seen an immediate improvement in my collection. Leaf color has improved to a dark, verdant green. This also holds true for the masdevallias John Leathers grows in the same greenhouse after he moved them into Orchiata. Prior to Orchiata, his coccinea’s had become alarmingly chlorotic in the fir bark we were using. My odont bulbs are fat and turgid. Their roots are the best I have ever seen them in my 30 years of growing. John and I are sold on Orchiata. Using it also pays off in the reduced need to repot saving time and material – well worth the extra cost of this media.

I’ll close by stating I am sold and a zealous proselyte for Orchiata bark. I’ve recently become aware there’s another importer of New Zealand Pinus Radiata bark. It is sold by a different supplier. I have no experience with this product. I do know it is not prepared in the same manner as Orchiata. Caveat Emptor.

I wholly endorse Orchiata bark.

Given its long pot life and clean, uniform character, right out of the bag, you won’t go wrong.


by Robert Hamilton, Hawk Hill Orchids
Recently, I received email from Russ Vernon asking me to update my experience with Orchiata bark. Russ heard from a prominent Southern
California grower his collection had suffered root damage when grown in Orchiata. The barks pH had dipped too low to sustain roots. In the appended note I’ll share my experience which does not corroborate this.

My partner John Leathers and I began growing in Orchiata after we were invited to share the cost of a shipment with Golden Gate Orchids. This was a generous offer and an act of kindness and good will on the part of Golden Gate.

At Hawk Hill John grows masdevallias and I grow odonts. Our initial order was for 100 bags of bark. We chose bags of two sizes, half the order was medium and half was fine (Orchiata has a confusing and bizarre way of branding bark size which even today I cannot fathom).

We had heard from growers we respect, namely Andy Easton of New Horizon Orchids, Kevin Hipkins of Royals Orchids, Australia and other “Anzac” growers the product was excellent. I am guessing that first order was about four years ago. The reason for turning to this offshore product
was simple.

The bark we were buying, which came from a producer in Oregon, was at best “iffy” in quality – poor is probably the better word. Some shipments were fair while others were poorly graded. The shape of the bark was not conducive to keeping open space in the mix. Our plants were suffering.
This fir bark was lasting less than a season. While on the roof one day I noted a dead zone in the area I was dumping spent bark. The situation had gotten bad enough that we got in our car and drove to Redding, on the Northern California border, to inspect the bark of a different producer, a
distance of 211 miles. While better, we were not impressed.

We initially used Orchiata straight out of the bag with no amendments. Because the cost of this premium bark was higher than local products we began amending the bark with lava-rock and charcoal, eventually abandoning charcoal as messy and useless. Initially, no buffer was added (a
buffer is typically some compound of calcium that dissolves in proportion to the acidity of a substrate thus keeping the pH somewhat constant. Dolomitic limestone and oyster shell are two such products).

Our immediate effect of changing to Orchiata bark was dramatic – excellent plant and root growth. We can also share experience with the lifetime of this product. I am ashamed to admit there are still a few plants that remain potted in mix from that initial trial. Note, this four-year-old bark: it has
begun to breakdown which is something you’d expect from a mix this old. It is holding more moisture than it should and the tops of the pots are showing algae and moss growth – an indicator that the bark has exceeded its lifetime.

In response to Russ’ inquiry I performed a “soil paste extract”, a standardized protocol for measuring substrate pH, on my oldest mix to see if there is a pH issue. Indeed, there is. This old bark measures a pH of which is quite acid – too low for good growth. Some roots in this old media have suffered. Having said this, four years is an outrageously long time for an orchid to remain potted in a mix. This is a testament to my laziness.

As experience with Orchiata bark progressed I began amending it by adding oyster shell as a buffer. Living on the California coast this is an easy material to get. It is sold by agricultural suppliers and in pet stores for bird owners and tropical fish raisers.

With time, after inspecting excellent growing done in our greenhouse which is shared with Tim Brydon, I followed Tim’s lead and began adding red lava-rock, about the same size as the bark, to the mix. Thus, I now had a buffered mix more likely to maintain a stable pH and the lava-rock, being cheaper than the bark, is a cost savings. Up to 50% does not seem to interfere with excellent growth.

I am currently repotting my collection en-masse. The current bark/lava-rock mix is holding up very well. I should say – excellent. The roots look great (having said this, there are some odonts that, probably because of their genetics, never hold good roots). There is nothing that makes motives change from this excellent mix. We just purchased more Orchiata. We’ll continue to add a calcium buffer as well as lava-rock as the lava-rock filler is cheap and, as an added benefit, lava-rock adds weight to the pots.

So, what’s up with the warning Russ received from the Southern part of my state? I can’t say. Was it “el Toro poo-poo”? There is fact in the issue that aging bark substrates experience a pH shift toward acid. This holds true no matter what source bark is used. From my experience, Orchiata is by far the most stable and best bark I have used. Is four years a long time to keep an orchid in a mix? Yup, four years is too long.

Having said these things I cannot account for another grower’s culture. Incorporating a calcium buffer will extend the lifetime of a mix. I suspect such buggers should even be applied annually but do not have experience with this (perhaps a grower with more experience can elaborate)? Lava-rock is cutting costs and keeping the pots more stable because of its weight. It does not seem to hurt anything at 50% volume by volume.

In noting my continued endorsements of Orchiata, please bear in mind we’ve received no considerations from this firm.

We do not resell bark or for that matter orchid sundries.

I remain an advocate for Orchiata bark. Try it, you’ll like it!