What's the difference between annual & perennial plants?
Here's a useful tip from plant biologist Ken Thompson. "If you're ever unsure about whether a plant is an annual or a perennial, a quick test is to get hold of it and pull. An annual will come out of the ground with relatively little effort, while a perennial - unless very young - will not."
"For sheer flowering firepower, annuals are unbeatable, because flowering is what they are all about. For an annual the only route to immortality is to produce lots and lots of flowers, and thus large numbers of seeds, and to waste as little time and effort as possible on anything else. But perennials, whether woody or herbaceous, have other things on their minds. A perennial may, briefly, be smothered in flowers, but it can't keep that up for long. Essentially it has to spend scarce resources on the things that will ensure its survival, which is, basically, roots".