For those of you in zone 6 and south, and possible some parts of zone 5b; there are annuals sold at the stores that are semi- hardy. What does that mean?
It means that they may very well survive your winter; the farther south the more likely they will. Why is this important?
To a Lazy Gardener like myself, the idea of planting annuals that come back like a perennial sounds too good to be true. But here in zone 6a – and in a cold spot in 6a – all forms of Dianthus will survive all but the harshest winters. They respond just like perennials in that when they come back, they are the large gallon size plant rather than the six to a pack size plant set out last spring. Keep in mind that they still perform like an annual by blooming all season long. You can always encourage more blooms by dead heading, or snipping off the faded blooms. It keeps the plants forever trying to make new blooms to try to make seeds.
Last Year's Dianthus sold as an annual. Be careful when you mulch in the winter not to cover the crowns.
Dusty Miller (Senecio cineraria) is another good plant that will survive the winter. If you have a green house or can cover your Dusty Miller it will be a large lovely plant the first day you can set it out. In insulated pots in sunny areas, the top growth will die back but the crown will survive. As soon as the weather warms it will send up new leaves.
Dahlias and Gladiolus, when planted 6 inches deep in the ground, not in pots, will return every spring bigger and better than ever. Throw some bone meal on them and they will respond with giant prize winner blooms.
These Dahlias were grown in pots, but I have a greenhouse to keep them in during the winter. Sunlight is not necessary, only a frost free location. Six inches down is frost free here where we live. - Just a side story - this photo was taken about 30 minutes before a tornado came through the area. The dahlias were destroyed, so were many many homes.
Combine semi hardy annuals with a good selection of perennials and reseeding annuals, and you have a garden that will just about take care of itself. The judicious use of pre-emergents allows you to get rid of weeds but stopping it at the proper time to let your plants throw off their seed to propagate is essential.
Violas sprout in warm weather, around September. So where you have violas, if you stop the pre emergent for the late summer early fall period, your violas will reward you with masses of new plants that will be large and very healthy by spring.
patch of re-seeded violas
Hold off on pre- emergents in your regular annual beds around last years zinnias, salvia, impatiens, marigolds, and the like, and they will sprout a nice new crop that by mid summer will be in full bloom. Be sure to put down your pre- emergent around theseplants in the summer and fall to take care of weeds, but drop the February/March dose. After they have sprouted, re apply the pre emergent to keep out the summer weeds.
By using plants that will take care of themselves and last longer than one season you can cut your gardening chores significantly. The hardest part, the part that makes me ache the most is the stooped over planting of annuals. So anything that keeps me out of that position as much as possible makes my Lazy streak very happy.