Hello Professor Lee,
This year I decided to start my plants early in a bare bones garden in my basement to give them a head start on the spring before I move them out to my greenhouse. I have three plants in plastic pots filled with a simple soilless mix and I’ve been feeding them with a mild fertilizer once a week. I’m using a 400-watt MH lamp and some reflective panels to light them. There’s snow outside but the basement is dry and cool (but not cold) and the light seems to heat the space pretty well. There is a floor drain so when I water I just let the run off drain to it; this way I know I’m not leaving the soil waterlogged. I feel like I’m doing everything right, but the plants just aren’t growing well. They are five weeks old and should be much bigger from my previous experience. I can’t seem to find the problem. The pH is good, the fertilizer isn’t too strong, and the light is about twenty inches above the plants. Any suggestions?
It’s a great idea to get a head start on the spring. Your plants will have ample time to grow as robust as possible before the fall. You seem to have your bases covered pretty well with one exception. It sounds like you have your containers sitting directly on the basement floor. Even if the room feels reasonably warm, a basement floor, usually concrete, can be quite cold. This can be transferred directly to the roots which will result in stunted plants. I suggest elevating them off the floor a few inches with either some type of insulation such as Styrofoam blocks or with something that allows for air flow around the bottom of the containers. I find a basic wooden palate does a great job and can be found online for next to nothing or in alley ways behind businesses for free.
Let me know how things work out!