My favorite answer is annuals are planted every year, hence, always planting annuals. Perennials are a permanent garden addition. Got a minute? Let me explain in greater detail . . .
ANNUALS are rapid growers, progressing through their entire life cycle – germinate, bloom and set seed – in just one season, providing the biggest color bang for your buck in the garden. Annuals will continue to bloom until the cool temperatures and frost of fall.
Annuals are also a great to plant over spring blooming bulbs. I do a lot in my home garden. It’s my little trick to protect the bulbs . . . from me!
As summer rolls in and the foliage from those beautiful spring bulbs fades away, I see bare spots that beg to be planted, perhaps a new perennial could go there. But when I would dig in, I find I had already filled the space with bulbs, too often spading them in half.
My solution was to plant summer annuals between the fading foliage of the bulbs, or as soon as they were ready to remove. Problem solved! Plus I would now have color until frost! Win! Win!
PERENNIALS are in the garden for the long haul. Pay attention to foliage, form and texture because they need to provide interest even when they are not in bloom. Depending on the variety and weather, perennials will bloom from a few weeks to several months.
When planting perennials, remember “sleep – creep – leap.” This refers to their tendency to focus on root growth the first year, creep a bit larger the second year as they become established and then explode to maturity in the third year and beyond. Many will need dividing by the fifth and sixth year.
LANDSCAPING TIP: One of my favorite combinations is a cluster of daffodils planted within a triangle of daylilies (allow a couple feet for the bulbs) and add sunpatiens over the bulbs as the foliage fades, the daylily foliage also helps hide the bulb foliage. This also works well with Hosta and impatiens in the shade.