When the first frost blackens the foliage of dahlias (or if a hard freeze is predicted), cut off the stems about 6 inches above the tubers. Carefully dig the clumps with a spade or fork, and and let them dry out of direct sun and wind for a day (not too long or they'll begin to shrivel). Store the tuber clumps whole (you'll get larger plants), or make more plants by carefully separating the tubers from the stem, making sure to include any "eyes" (small, raised nubs near where the tubers attach to the main stem) with each tuber. These are the future sprouts. Store tubers in cardboard boxes filled with peat moss, vermiculite, or sawdust. Keep them in a dark, 35- to 50-degree F location.
Overwintering Tender Annuals
If you have good indoor light or grow lights, you can keep fuchsias, geraniums, and begonias flowering during the winter, or at least for awhile longer. If you want to let them go dormant, cut the stems of fuchsias and geraniums back to the edge of the containers and store the pots in a cool, dry location. Stop watering tuberous begonias. When the foliage drops, remove the tubers, rinse and dry them, and store them in perlite or vermiculite in a cool, dry spot.
Clean Tools and Pots
Begin preparing tools for storage. Clean the soil off shovels, spades, and trowels using a rag or wire brush, then wipe blades with an oiled cloth. Make sure pruners are free from dirt and plant debris, and wipe down the blades with the oiled cloth. Empty pots of dead plants and soil, adding the debris to the compost pile unless the plants were diseased. In that case, dispose of the plants in the garbage or a location far away from your garden. Rinse pots.
Prepare Soil for Next Spring's Roses
Roses need a well-loosened and amended soil, so prepare the soil now for spring planting. If the bed is in a low spot, add coarse sand and topsoil to raise the level. Then mix in peat moss or pine needles for a little acidity, compost or peat moss for aeration, and manure or cottonseed meal for nitrogen.
Harvest Brussels Sprouts
As the weather cools, look for Brussels sprouts developing along the stalk. Start harvesting from the bottom and work your way up. To encourage the sprouts to grow large, cut off the tops of the plants so the plants will redirect energy to the developing sprouts.