Grow Q&A: Understanding Vegetative Time

Danny Danko

Dear Dan, I have a question that I have not been able to answer based on my small, personal 5-6 plant grows. I usually veg for at least 5-6 weeks but sometimes let them veg as long as 8 weeks. My question: Is there an optimum length of vegetative time, when looking for maximum yields? For example, if four weeks of veg yields 45g/plant would eight weeks veg generally yield more? If so, how about 10 weeks? I’ve done some experiments with Veg time but have not drawn any firm conclusions. – Hi4daze

Dear Hi4daze,
There is no ideal amount of time to keep your plants in their vegetative stage. You decide for yourself how long you want to take to build leaves and branches of your plant under 18-20 hours of light, and then induce flowering using 12 hours of light and 12 hours of darkness. The longer you keep your plants in the vegetative stage, the bigger your plant will be, resulting in bigger yields from plants that were vegetated longer.

The drawback to a longer vegetative period is the fact that it takes more time, lengthening your growing schedule and allowing more time for things to go wrong along the way. Vegging a plant for three months is a waste of time so think of it as something with diminishing returns when you overdo it. I usually recommend a week of veg time for every gallon of growing medium (ie: a plant grown in a 5-gallon bucket should get about a 5 week veg). Most people veg their plants anywhere from 2 weeks to 2 months but there are Sea of Green growers who hardly veg at all and large plant experts that go longer. The important thing is that the plants are healthy throughout this vital stage of growth. That way, they’ll be ready to pack on the flowers during the blooming stage.