What Causes Smaller Leaves & Stems?

[Bloomer001]

I purchased 6 phal orchids from Wholefoods last spring. They all had double stems and large leaves when I purchased them. Around June I cut the stems bc I thought this would help foliage growth (I have now learned this is debateable). Over the summer all orchids had A LOT of aerial root growth, but all the new leaves were smaller (each orchid grew 3 new leaves over the summer & early autumn). The new leaves grew upright and didn't lay down (see pics). In the fall, each orchid only developed one flower spike. Some are cascading and they are about 25% shorter than last years spikes. Does anyone know what causes a lot of root growth and smaller stems & leaves? I would prefer less root growth and larger leaves & flower spikes.

Here is my culture:
They get 12 hrs full spectrum artificial light daily (about 1k cf), high N Miracle Grow fertilizer, MSU pellets, and I recently started CaliMagic for extra calcium & magnesium. (I just started a new fert regime on 3 orchids). Upon purchasing them, I repotted them in RePotMe Phal mix and put them in plastic pots with airholes. They are watered weekly in their containers with fert mix (I don't remove them to soak) and I spray the top soil and roots mid week with fert mixture.

[Louis_W]

In my opinion you should not compare your progress to how the plants came in the store. The nurseries that produce those know exactly how to grow them for good flower production force blooming whenever they want.

Your plants look very healthy to me and the fact that they are growing leaves, roots and flowers indicates that they have everything they need.

Again this is my opinion, but you are currently setting your reference point. You can compare next year's growth to this year's and see what you can do better.

[Dimples]

Plants grow what they think they need based on the conditions that they’re living in. If they’re growing lots of roots then the plants have decided that they need more roots. Plants don’t waste energy/resources growing tissue they don’t need.

I’ve also found that repotting a healthy phal will almost always spur root growth so long as there’s enough light and warmth to support it.

Remember, plants grow roots, then shoots, then fruits (flowers in this case). Keep doing what you’re doing!

[estación seca]

Your plants look great and you're giving excellent care. They don't carry as many, nor as large leaves in a typical lower humidity and temperature home as they do in a warm to hot, very humid greenhouse.

[Dimples]

And the upright leaves are just new and stiffer than the older leaves. Those are the leaves that your specific growing conditions produced.

The older leaves also grew in a humid greenhouse. Home conditions anywhere except the tropics will be considerably dryer than a greenhouse. The older leaves aren’t going to be well adapted to a dryer environment, so they’ll often stay slightly limp forever. It’s normal.

[Ray]

If each successive leaf or growth is smaller, it is indicative of a lesser overall cultural regime.

If, on the other hand, they are a bit smaller and subsequent ones continue at that size or slightly larger, it might be an adjustment to new, possibly more favorable conditions, such as an increased light level.

[Optimist]

No high nitrogen in Phals, or any orchid, really. The roots are just what is genetically programed into the plant. It is seeking out moisture. They also grow on trees and cling to the bark of the trees. They do not stay in a small pot. Last, the smaller leaves will become the larger leaves when the bottom leave falls off. The bottom will fall off (turn yellow and die and just pop off) when its time has come. The plants "sacrifice" some part of the sugar store to feed the next generation's flower. In monopodial orchids that means that one leaf is the equivilant of a pseudopod -- Orchids that are sympodial (cattleyas, even paphiopedilums) will sacrifice the older growth. This is similar to bromiliads and just a survival strategy that is genetically programed in the plant.

[Mountaineer370]

I'll only add that, those new leaves being from this past summer and fall, they may not be done growing yet. I've experienced a few times when it seemed like new leaves on my Phals looked smaller than the older ones, but as time went on, they "caught up," so to speak, and they also flattened out with time.

I think all your plants look great!

[jldriessnack]

So, in my experience, phals can at times produce smaller leaves and shorter spikes when they are exposed to TOO MUCH light. If this is the case, the leaves of your phal may be too bright a green. If the leaves remain fairly dark, then it could also be the opposite, too little light. Remember, in nature, phals rarely get 12 hours of good light, they grow under heavy canopy. Fertilization (nitrogen) can also make a huge impact on foliage, so consider that. And then of course, a night time temperature of below 74F about, inspires flowering. I think they look fine to be honest, but I would try fertilizing more. Just be sure to dilute more then recommended.