Annuals bloom better if the old flowers are removed. This prevents seed formation that normally makes annuals start to decline. The practice is particularly important when growing ageratum, calendula, cosmos, marigold, pansy, rudbeckia, scabiosa, verbena, and zinnia.
Whether you test for radon yourself or hire a state-certified tester or a privately certified tester, all radon tests should be taken for a minimum of 48 hours. A longer period of testing is required for some devices.