Just wanted to add some more thoughts on D.E. as to why it is so useful for the above purpose as well as many others. Insects don't have the ability to clot (unlike humans)their internal fluid (blood) there for if they get pricked they will literally bleed to death no matter how small the cuts are. D.E. can even be applied in a sprayer (with a small squirt of dishsoap to help stick it to plants or other surfaces) if kept agitated so as not to clog the nozzle. Then when it dries it will be reactivated. It will wash off so will need to be reapplied if rain or over head watering is used. The one thing I always remind folks about DE is that it is a dust and needs to be handled carefully so as not to breathe it into your lungs. (not a good thing). Use a standard dust mask if air borne dust is a possibility. Not trying to horn in Al, just offer more info on the subject.:) Happy Growing David

Thank you so much for the replies, everyone! To answer some questions: To test to see if the plant needs watering, i usually stick my index finger down into the soil and if it feels dry, i give it about 1/2 of a liter of water. I usually put the cold and hot water on equal amounts so the water is lukewarm . The terracotta pots the corn plants are in is 11 inches. There is a big issue with light in my house. I live in the middle unit in a condo so I have NO East or West facing windows, they are all North or South. The only North facing window that gets adequate light is on the 2nd floor where it is warmer, but there's no real place for the plant. I may move it up there though after what naturelover said. I never even thought about the cold that could draft in from that window. Yes those are patio doors they lead out to my backyard and are really the only source of bright light I have for my plants. So here's what I'm thinking. I probably killed this plant in many ways, not just one. I probably poisoned it with Miracle Gro (foolishly thinking it wouldn't go into shock if it had food to eat, hey that's what I'd want is plenty of food if I were moving into a new home, but I guess plants may feel differently). I probably drowned it. And then I probably froze it. Haha. Miracle it's still alive at all. This is what I'm going to do: Prune the dead, brown leaves. Soak the pot and shower my plant as breenthumb suggested. Move the plant to a warmer, non-drafty room where it will get slightly less light, but hopefully will be happier. Don't water the plant for a couple of weeks. Pray. Should I leave the pale leaves on and hope they recover? In the future, is 1/2 a liter of water too little water or "little sips" as rhizo said? Mind that these plants are about 3ft high and in a 11 inch terracotta pot. I'm at work right now, but I'll post pictures of my plants and of their new locks when I get home. Let me know if there's anything else you guys think I should/could be doing to save my little ones :) & Again thanks so much :)

I dont know if this is an issue in the UK, but here in Western Australia - what you are describing is generally caused by water repellent soil. Dusty sandy soil can prevent water from penetrating roots and deprive the plant of nutrients and water - even if you are flooding your plant. put a few drops of water into the soil. if it beads up then that is your problem. The solution is simple. buy a wetting agent and add a small amount every few months or so - via a watering can or spraying it. wetting agent is nothing more than a detergent which breaks down the surface tension of the water. You can use household dishwashing liquid but I dont recommend it for regular use as unlike commercially prepared wetting agent - dishwashing detergent will change the PH of your soil. Adding considerable organic content into your soil is also a good solution.

I suggest you visit the Hydroponics Forum as they may be more help. But I also suspect that a rather large outdoor weed may have challenges adapting to a different growth system. You might be more successful starting with a much younger plant which will grow indoors. Perhaps ask the Hydro folks for suggestions. http://forums.gardenweb.com/forums/hydro