When asked to participate in a 2-year Fern Fibre substrate over Bark/Pumice experiment six months ago, award-winning orchid grower Allan Watson was up for the challenge. His photos clearly show the differences.

Miltoniopsis Substrate Trial: 6 months into a 2-year project.

With some Shakespearian liberty… “Is it to use bark on not to use bark? That is the question.”

Setting up the Trial

Having been asked to participate in a Fern Fibre substrate over Bark/Pumice trial some six months ago and looking for a challenge, orchid grower Allan Watson from Taranaki, New Zealand, said yes.

At the time, he had no previous experience with the Fern Fibre substrate, yet he had heard lots about the end results others were getting, so he set the trial up with an open mind.

“Liking measures over hearsay, I set up using the apples with apples approach. This meant in the first instance any Miltoniopsis that I had two of one would remain in the bark /pumice mix and the other would be placed in straight Fern Fibre. This allowed me in the first instance to establish 15 pairs of trial plants,” Allan clarifies.  

Both plants would remain in the same environment side by side and receive the same level of watering and fertilizer. Allan subsequently put any new additions to the Miltoniopsis collection into straight Fern Fibre, along with a number of other different genera. This now gives him some 40 Miltoniopsis in Fern Fibre substrate, and the number is growing.

“As with any trial I believe for it to be meaningful then measurements need to be applied. In this case it becomes quite difficult as the end results tend to be visible. Nevertheless, tracking observations on a formal record seemed to be the way so a conformation of result could be presented,” he says.

Adopting time frames seemed to be the most practical first step for Allan, followed be detailed conformation of time lapsed progress.

“I decided be it right or wrong to adopt a 3-month observation timeline this means every three months I apply an outward, apples with apples view of the plants in the trial and note observations. At the six-month phase based on a wider sample group, I would also comment on the performance of other Miltoniopsis within the extended trial. In addition I would remove two like Miltoniopsis from their pots and view the root structure. This action is timed to occur around their mid growth cycle.”

First series of Observations:

Both these Miltoniopsis were potted up on the same day. As you can see, the one in the left of the photo is in a mix of #2 pine bark/course pumice at a ratio of 3 to 1. The one on the right in straight Fern Fibre substrate. You can clearly see that the plant on the right has developed further in size, colour, and overall appearance when compared to the one on the left. All other 14 pairs showed a similar result.

Mps Robert Jackson ‘Wild Thing’

It was this performance that left Allan with little doubt that Fern Fibre produced positive results, so he decided to extend the trial to a further 21 Miltoniopsis that he had ear marked for his breeding program.

The photo confirms the growth and development aspects apparent in the apples with apples trial. Plants are around 30% bigger than those in bark /pumice and looking overall healthier plants.

“For interest sake, the breeding stock has been set up to provide three opportunities with each of the common Mps. flower configurations. i.e. Reds, Pinks, Yellows, Red Waterfall etc. It is hoped that some new hybrids can be introduced into the current range available in New Zealand,” Allan says.

Second series of observations:

The first set of observations seemed relatively easy to obtain, in other words, just look at the plants and note the physical differences. For the second set of observations it, in Allan’s view, seemed necessary to remove the plants from their respective pots and compare any root development. As all seemed to be performing the same, only one pair will be subjected to this observation. One other reason being that he did not want to upset any spike development with opportunity to display plants at orchid shows in September.

The Miltoniopsis used in the next two photos is Mps Rene Komodo ‘Pacific Clouds’. Allan hasnoted that the Miltoniopsis in the bark /pumice mix tend to show sign of root growth on the surface as per the plant on the left whereas those in the Fern Fibre substrate tend to develop within the substrate.

Now for the real test, removal and exposure of the plant root structure. They say a photo speaks a thousand words, along with seeing is believing. The plant on the left was in bark pumice mix while the plant on the right was in Fern Fibre substrate. Allan says that there is only one positive result.

Despite being watered only two days prior, the roots of the Miltoniopsis on the left were dry where the plant roots on the right were moist not wet. As expected, you can also see the growth intensity difference between the two. In both cases the roots presented a healthy appearance.

The other noticeable observation relates to the depth of the root growth with the Miltoniopsis on the left being in the top half of the 1.3l pot where the Miltoniopsis on the right tended to spread down and out to about 3/4 of the depth of the same size pot

“So now I wait, the spike phase followed with fingers crossed the flowering stage of this trial. At this stage I can only see one outcome that being a complete substrate change for all 108 Miltoniopsis in the collection.”

A big thanks goes out to Alan Ford of Fernwood Products New Zealand Limited for asking me to be involved in the trial of this substrate,” Allan Watson, orchid grower from Taranaki.