Justin121:
Am I correct in assuming that you're growing with an Aerogarden? I try not to top my plants because I was taught by a reliable source that it can take them ten days to recover under the best of circumstances. You can have the topical buds of your plants within an inch or two of the cooler flat CFL's in an Aerogarden without a problem. That's a major of the advantages when growing with an Aerogarden. When you reach the 24 inch height limit, if you have one of the super duper models, you can gently bend them over, tie them off on the stem just below the topical bud with four pound nylon trout fishing line and weight them to control the bend with lead crimp on split fishing weights. Of course if you're not a fisherman I may be speaking Greek to you.
If you have one of the older models that only extends up twelve inches then you have a different problem. You can replace the arm and hood with what A/G calls an "upgrade kit." I think they run about $110. I've had mine for a long time and don't remember exactly. The upgrade kit will give you a hood with three higher intensity flat CFL's and an arm/light stand that extends up to a full 24 inches. I hope this helps.