Spearmint growing to tall and thin?

I recently purchased a batch of spearmint at Home Depot. The plant was very dry (the dirt looked like light brown dust) but it seemed to be healthy enough. I put it inside in Moisture Control potting soil and about a foot or so below a 15 watt fluorescent grow / aquarium tube. The light is one between 10-24 hours a day but usually around 16. The light is in my bedroom so often when I can't sleep the light has to go out.





The plant started growing rather fast but now it's growing leggy. I think that's the term. It may grow about 2 to 2.5 inches between leaves and some of the tallest ones seem unable to support their own weight. A few died but I think they were probably damaged by being dry and my slight over-watering reaction. The perplexing thing is that some of it is growing like gang busters and some is getting leggy and weak. New growth in particular seems to be coming in strong. Is this a normal adaptation to being indoors?

Spearmint growing to tall and thin?
Spearmint is meant to be harvested. It will get leggy and weak if not. to encourage a bush plant it needs to be pinched back every so often. You don't want it to bloom either cuz then it thinks it's life cycle is over and it will go to seed and die. Maybe this link will give you some help. Good luck with it.
Reply:The plants probably need natural sunlight. If you could move the container outside part of the day or at least to a window, it would help. Strangely enough, plants grow faster (but grow weaker stems) in the dark. It's a survival mechanism. Say, if a rock fell on top of a plant, the plant would then speed up growth to reach sunlight before it died.





Also, spearmint grows to about two feet tall. If you have a place to plant it outdoors, that would be better. Planted outside it is a very low maintenance plant, and will come back every spring.
Reply:if you want a plant to get fuller, you need to trim it back.
Reply:A 15 watt bulb is not a good light for your plant. There are two problems with such a lamp. First, it is just not enough light for such a plant. Your need much more light to avoid the effect you are seeing. In addition, incandescent bulbs have way too much red and far-red light. Both low light and light-quality with high red:far-red ratio will encourage the etiolated growth habit you are seeing. This is a normal plant trait, where they search out more light to grow by elongation and spindly 'stretching' to reach better light and is controlled by the photoreceptor phytochrome (which equates the high red:far-red ratio as indicating it is underneath another plant's leaves). Change your lighting to a set of 2 or, better, 4 cool white florescent tubes, each 40 watts, and you should do much better. Of course a window getting direct sun would also be helpful.