Plastic bags work well; but do check on heating, so as not to harm the plants. Your library will have books for this or use the search engines on your computer-Google, Yahoo, etc. to look this up. Good Luck.
By
01/27/2012
There are several ways to tent a houseplant, the best ways include a supportive frame (bamboo skewers, coat hangers, etc) so that the tenting doesn't touch the foliage of the plant. Also important is to monitor the heat being generated by the tenting to make sure the plant is not over-heated.
Do a Google image search to see pics, that's the easiest way to figure out the best method for your particular plant and environment.