Seed starting under grow lights. I started a loofah plant about a month ago, because they didn’t even get close to maturing last year direct seeding them.
It’s huge, already vining, and almost at the point where it will no longer fit under the grow light with the other plants, but it still way too chilly to put it outside. Any suggestions?
I would prune it back some and try to root the cutting in water (I’m always trying to propagate something lol).
I’m kind of in the same situation - started my melons two weeks early. I more so care about having a well developed root system and planned to cut back the growth anyway at transplanting.
I have used a cold frame to help out A day in the cold frame, you don’t need lights.
Mine boosted temps by 20 degrees. If it’s 40 and sunny it’s 60 in the cold frame.
i tip them then tip again. can always let them go once they are outside. did that to my peppers last spring and had huge yields on nice compact plants.
I usually use small chains on my grow lights and move them up as the plants get bigger keeping the light right on top of the plant because i still use old fluorescents. There is no such thing as to big in the case of my lights because they were intended for trees or veggies.
I had one years ago. I found I was unable to babysit it enough to keep the plants from baking on sunny days, and it only seemed to add maybe five degrees of freeze protection at best. It was poorly constructed though 
It’s the lateral spread, not height that is the issue. It’s crowding out other plants.
Can you run them up some bamboo?
When mine are growing too large, I set them outside in 60 degree, sunny day. It will slow the growth without damaging roots or growing points. Works well on peppers, tomatoes, and cucurbits.
Even vertically, I couldn’t fit it under the grow light. So it’s in the sunniest windowsill in the house.
With this forecast I don’t know when I can get it outside.
I’m hoping I can limp it along for about 7-10 more days and maybe get it transitioned outside.
I am a little late starting my Loofah, Bitter melons, and Vietnamese Gourd calabash two weeks ago. They just barely poked out of the ground. That is fine because that will buy me time to build the PVCs trellis for them.
Depends on how badly you want it to grow. If bad enough, I would put a mini greenhouse on the warmest place outside, place some boards, then insulation, than boards again and seed starting mat on top. Put your pot inside on op of the warm mat. Keep opening/closing the greenhouse during the day. For the night have some 200 W terrarium bulb and thermostat ready as well. Cover the greenhouse with insulation for the night helps. This is how I keep my overgrown starters in the portable greenhouse on my deck. It is a 6X8 basic plastic greenhouse, so just bulb doesn’t work for me, I use an oil heater and fan.
I was able to slow growth down in my grow-box by reducing the heat after germination. But temps too low, you’ll stunt them.
