Hello Buddy. I read years ago... to keep plants in veg outside, They need a strong light on them about 1/2 way through the night for about 3 to 5 minutes.
This resets the night clock and the plants don't go into flowering. Read a funny story years later that reinforced that.
2 neibour's had a yearly bet... who could grow the most pot... with the same amount of plants.
One of the wife's got up through the night to have a pee and noticed through the window, a light coming from outside, near the pot patch.
You know those super strong flashlights with 2 million candles power and can shine for 1/2 a mile,
One neibour was shining his strong flashlight from his sundeck, in the middle of the night, on his neibour's patch.
To keep the plants in veg so he could win the bet, like he had done for years.
Make sure the light doesn't light up the yard, or attract attention to your plants. Hope that helps.