Most ageratum plants need deadheading to keep blooming, but ‘Artist Blue’ plants don’t need to be trimmed back, as the new flowers will cover the old ones. Pentas are easy to start from cuttings that you save at the end of summer. If you live in a frost-free zone, expect your pentas to maintain their vigor for about three years before becoming woody and lanky. At this point, it’s time to remove them and start with fresh plants. If you spy caterpillars on your petunias, don’t mistake them for butterfly babies. The tobacco budworm is a serious petunia pest, and you should destroy any green munching larvae you find. Prostrate verbena varieties suitable for smaller containers or hanging baskets include the ‘Lanai’ series or the trailing ‘Superbena’ series. Extend the bloom time of verbenas by cutting them back and fertilizing them when they start to look lanky.
