How to keep stems short?

My first grow ended up in the toilet. Somehow my stems grew about 6 inches before leaves and plants just toppled over. WTF Little help here?

you need more light

you have to give us more info if you want help. What kind of lights? How far away were they. What was your grow room environment like? A little more info would be helpful

keep the lights as close as you can without burning them, get as much light as possable.