|I am trying to grow tomatoes from seed. Every time I water them one or two will lean over, then wilt and die. I am thinking the falling water might be washing the soil off the root, killing the plant. Would it be better to grow them in a cup where I can water the pan below and let it soak up instead?|
|If your seedlings fall over immediately when you water, they could well be undermined by the force of watering. I suggest that you firm the premoistened planting medium in the flat or pots before planting seeds. Don't go to the other extreme of packing it in, though - plants get their support, water and some air from soil, they don't grow well in hard-packed soil. Water with a misting bottle until your tiny tomatoes are sturdy, or drip water gently held close to the soil. Or you can soak the potsin a tray of water, as you mention. Just be sure the plants don't sit in water and become waterlogged.
If the seedlings keel over right at the soil level like a felled tree some time after you've watered, they're suffering from "damping off". Damping off is a fungal disease that attacks young seedlings, or can prevent germination altogether. Conditions that favor damping off are: Crowding of seedlings, high humidity, and lack of sufficient aeration. The fungal spores are prettymuch everywhere, so your best bet is to maintain good air circulation and to not overwater. Keep seedlings thinned, and place a small fan set on low somewhere nearby will do the trick to keep air moving. Try to keep the growing area relatively cool (60-65F), since tomato seedling grow strong at these temps, but the fungus likes it warmer. Since the fungus enters the plant at the soil line, you can try this method, too: once the seeds are planted, but before they germinate, cover the soil with a fine layer of "play sand" (this is sand that has been sterilized; you should be able to find it at a hardware store or lumberyard). This provides a sterile, dry -- and therefore unfavorable to the fungus -- surface at the point it usually enters the stem.