Tips wanted for growing watermelons in container garden on deck?

Give full sun, and I would remove some of the flowers. Fertilize after every time that you water, unless you have used enriched soil. Make sure the container is large enough. Putting something under the young melons are not necessary. They grow out in field of dirt which has all kinds of insects in it. I have never seen them raised off the soil in the fields. Watch for insects, like white flies, aphids, mold, and take care of it immediately. Use can use soapy water on the plants, 2 tbs. per gal, spray it on. It won't hurt you or animals and you can't trellis them, the fruit will be to heavy.