The change in the leaf stems give them a higher surface area to volume ratio, which would make them more efficient at expelling and evaporating water. It would do this either to rid itelf of harmful ammounts of water, or to cool the plant, or a combination of both. However, leaves (foiliage) woud be naturally more efficient at these tasks than stems. So maybe something on the leaves like naturally occurring wax, or a build-up of sprays and dust, could be blocking the leaves from efficiently evaporating. Maybe hosing them down good with a light soap (quickly-you don't want to soak them if they are alteady too wet.) Good luck, and remember that new squash plants grow very quickly (from seed) and may be your easiest way out of this problem. -Terry This post was edited by terry_neoh on Thu, May 1, 14 at 6:12

Maybe exponential growth. When they have small differences in the beginning the one that did better had an advantage. So more leaves early leads to more growth early. Also yes being in the dark does cause elongation. Its also possible one is a nuclear tree and the other zygotic.

I grow basil indoors and have some fresh basil available year round for cooking. It's not the easiest to grow indoors, especially in the winter. For growing media/"potting mix", you can refer to the link(s) above and mix your own container mix. I've also had reasonably good luck for herbs (rosemary, sage, basil, cilantro and parsley) in either "Bonsai mix" or "Cactus, Palm and Citrus" mix. Sometimes, if the mix seems to retain too much water, I'll add some perlite to the mix to enhance drainage. I use clay (terracotta) pots with saucers. I don't put anything in the bottom of the pots for drainage. I actually use a single paper coffee filter to keep the mix from falling out the drainage hole. I fill the saucer with marbles (or stones) to keep the pot from sitting in any water that drains from the pot at watering time. The water won't wick up the marbles or stones and back into the pot, it will just sit and evaporate from the saucer. Temperature needs to be warm. My hanging planters are in the kitchen, not far from the wood stove which is supplemental (often primary) heating for the kitchen and bedroom "apartment" part of our home. Heat usually isn't an issue. It's 75F or warmer most of the time, with occasional nightly dips to the mid 60's. Light is also critical. In my kitchen, lighting generally is extremely bright. I've got a 4 tube fixture with T8 bulbs in it for general lighting. I mix 2 "Warm white" (2700K), 1 "cool white" (4100K) and 1 "daylight" (6500K). The kitchen was bright enough with just a two tube fixture, so it's very bright, even a bit harsh with that lighting. But that's not enough for "full sun" plants. It's not even close. Beyond that, there's a light fixture with an LED "spot" light built into my hanging planter. Those lights are fairly intense and look quite harsh. For basil and other leafy herbs, use an LED "aquarium" bulb with blue (~460nm) and white (15000K) LED's. Most "blurple" LED grow lights are heavy on the red end of the spectrum to promote blooming. That's probably desirable for "medicinal flowers," but that's not really what you want for culinary herbs. If I hang my planter/light setup in a sunny window with the light off, and put my hand where the shadow is in the pot, when I turn on the light, the shadow basically disappears completely. That's how bright your lighting needs to be for basil (or other "full sun" herbs) to thrive. Look for a bulb with a 30° beam angle (or tighter), and place it where the bright part of the beam fills the pot, but very little light goes beyond the edge of the pot. Usually, that position is a bit less than twice the diameter of the pot above the surface of the potting mix. Yellowing and dropping leaves indicates either too much water or insufficient light (or both).

Wow! That is just incredible! I wouldn't have thought to use that soil for container plants but I sure will do so when it's time for repotting :) If I may, I have one more question...not sure that you'd know the answer but you certainly seem to have a ton more experience with these lovely plants than I have so it's worth a shot asking! So I purchased a ZZ, "Zena" from my local Walmart a few months ago at the beginning of summer for $10. I had no idea what a ZZ plant was or if I'd ever even seen one before. I just new it was uniquely gorgeous and I had to have it for my fireplace mantle! All I've done is water it when I feel the top 2 inches of soil is dry as well as give it a couple of pumps of miracle grow plant food maaayyybe 3 of the times I've watered it (so maybe once in June, July & August). Since then, it has sprouted 3 new light green stems full of leaves and the shorter bushier stems have filled out quite nicely on the bottom making the plant look even fuller than when I purchased it! :) Well recently I came home from a trip and there was this short yellow stem of leaves. Not sure if this stem was one of the shorter bushy stems already present in the plant & those leaves just turned yellow or if this sprouted up new and yellow within the 3 days I was away at work? I'm at a total loss. Have done some research the past couple of days and some people have reported that it's a seasonal change that affects usually only one stem. Some have said the oldest stems will sometimes turn yellow and die off. Some think it's possible they may have a "variegated" stem of the plant growing in with the regular green version of the plant. Some even say that it's a sign of overwatering and the tubular roots inside could be soggy & dying. I don't think that's the case with Zena, as I make sure she's dry down to the soil at the drainage holes at the bottom of her pot before watering. Question is, have you seen anything like this with your ZZ's or perhaps have heard of this happening before and possibly know what it is? I've touched the stem & leaves & they look and feel quite strong and normal. They just look "odd" compared to all the other deep dark green stems in the pot. It doesn't bother me a bit, in fact I love eccentricities in all things so I feel blessed to have this little oddity sticking out the side now, but I just wonder if I need to be concerned? I should let you know that I live in Colorado and when I left for my trip the temps were consistently 75-80° inside the house but when I returned 3 days later it was 50° outside so inside the house it was about 65-70°. I wondered if maybe it got too cold & that caused the color change or new growth of the yellow stem? Any thoughts you might have are greatly appreciated! Thanks for your help! Len