How do commercial growers grow their leaves so big?

[netrizone]

Hey guys, I've been taking care of a phalaenopsis orchid for about a year now, and it seems happy. I water when the roots are dry, and it's been growing under some LED lights for 14 hours/day.

However, I've noticed that its new leaves are only 2/3 the size of its previous ones. How do commercial growers get their orchids to grow such large leaves? Is it the temperature? Fertilizer? Light?

[camille1585]

Welcome to Orchidboard!

Assuming nothing is lacking in your culture, one of the main factors influencing leaf size in Phals is light intensity.

In the wild, most Phal species grow in the shade of the tree canopy, so they grow large, wide leaves to capture the most light possible. Under higher light, the plant needs less surface area for the same result, and leaves tend to be shorter and narrower.

14h light is a fairly long photoperiod (though you need to factor in intensity), so it might explain why the leaves are shorter.

Commercial growers can provide optimal growing conditions (temp, light, humidity, nutrition...) so sometimes plants have an adjustment period once living in our less than optimal houses.

[netrizone]

That makes sense. Right now I'm using Barrina T5 grow lights. And I just measured the light intensity with my phone: the Phal is receiving a PPFD of about 100 umol/s/m2 for 14 hours every day. I think this would calculate to a DLI of 5.34 mol.

Assuming that orchid leaves grow larger to capture more light in the shade, could I theoretically decrease the PPFD (and keep the hours the same) to induce larger leaves?

[estación seca]

A 12- hour day in summer and 10 hours in winter is enough. Why spend more for electricity? Most epiphytes come from near the Equator and don't experience long days.

The Phals. I've seen growing in higher temperatures and relative humidity carry more and larger leaves, and produce more of them in a year, than Phals. grown in most homes.

[Ray]

While light certainly is a factor, I vote for water, as that is the true driving force for growth.

In order for any plant to add one pound of mass, it must absorb and process about 200 pounds (25 gallons) of water but only about 5 grams (a teaspoon) of fertilizer.

Then, if you add to those numbers the fact that a good 90-95% of the water taken up by a plant is lost through transpiration, that means to gain that pound, it must absorb as much as 4000 pounds of water to have 200 to process.

Your “water[ing] when the roots are dry” suggests it is not getting water at the rate it may need for sufficient growth. If you can figure out a potting medium that stays airy when it is saturated, and water more, you’ll see better growth.

[Fairorchids]

Coming from both commercial (1968-1977, and 2012 onwards), hobby growing in house (1994-2002) and combination (2002-2012) backgrounds, let me add:

Take 12 identical plants (mericlones). Grow 6 in your house under the best conditions you can provide, and grow the other 6 in a commercial greenhouse, where they are amongst 10,000 other plants.

At the end of a year, the 6 in the greenhouse will all be larger than the 6 grown in the house.

There is nothing wrong with this; it is simply that in the house, the plant is growing as well as it can under 98-99% optimal conditions. Ray quantified the water issue. Add to this the constant/higher humidity in the greenhouse, the natural light spectrum, and the natural temperature gradients.

Finally, there is the 'crowd factor', which is difficult to quantify. I have seen this throughout my commercial career, but have also seen it described in scientific journals (about other plants than orchids though):

Put 12 seeds from the same seed pod into pot #1.
Put 12 seeds from 12 different seed pods into pot #2.
After X months, the 12 seedlings in pot #1 are larger.

Put 12 seeds from the same seed pod into one pot.
Put 12 seeds from the same seed pod into individual smaller pots.
After X months, the seedings in the compot are larger than the ones in the individual pots.

The I have seen the latter phenomena repeatedly when deflasking orchid seedlings (Cattleya, Cymbidium, Paphs & Vandaceous).

[tmoney]

interesting note on the crowd factor, as we have seen this in the small number of seedlings we have deflasked (about 50). unfortunately there are no actual measurements to back up our claim, but anecdotally it is quite obvious that the approximately half of our seedlings grown in com-pots for the first year have grown significantly faster than the ones we potted alone right out of flask. not sure how this is relevant to the original question, just thought it was interesting....

[CocoSo]

I'm a newbie, so only a penny's worth but changing watering habits has had a huge effect on my Phals. They are in Orchiata and previously I soaked about once/week/10 days, frequency depending on season. Leaves averaged about 6-7 inches long. Now I water several times a week, flushing water through twice in 15 minutes. Since the change the leaves on all are growing progressively longer, 10-12 inches now and also considerably wider. I only have 4 phalaenopsis but have noticed the same effect on all.

[Roberta]

I think you have found the formula... good work! In a good medium, like Orchiata, with lots of air space, it's pretty difficult to over-water, as you have found - the plants LOVE water - as long as it comes mixed with lots of air. (Also a benefit of mounted plants, where overwatering is almost impossible)

[Dimples]

Don’t forget how important warmth is for phals. Warm and wet is great. Cold and wet, not so much. Seedling heating mats are relatively inexpensive, too.