This is the time of the year to make tough decisions about what will take up residence in the house and what will succumb to the frost. Though frost will inevitably kill off most of the tender plants that I have cared for all summer, some of these plants can be saved for next year.
During summer months, most gardeners place their houseplants outside, giving ample water and fertilizer to encouraging lots of growth. If you have limited prime real estate (south or west window), they may now need downsizing. Prized houseplants like my jungle cacti collection take top priority. The large baskets of wandering dude (tradescantia), Cuban oregano (plectranthus), and Joseph’s coat (alternanthera) will make the cut only through a few tip cuttings. I usually start my tip cuttings in a vase of water and plant in soil in early spring.
Remove a tip with four or five nodes. Remove the leaves from all but the top two nodes. Place in water and watch roots form. Be sure to refresh the water throughout the winter.
Overwintering in a garage
A few of the tender potted annuals will survive a winter in an unheated garage. Dusty miller, salvia, euphorbia, fuchsia, lantana and begonia can be saved in this manner. Just remember to give them some water a few times during the dormant season. Foliage can be removed as it browns or kept as an insulator for roots. In spring, plant in larger pot with new soil, water and fertilize once growth resumes.
Overwintering storage roots
I love the intricate leaves of caladium plants and have a hard time passing over them at the garden center. They can be saved by storing their roots in the basement. After first frost, remove foliage of caladiums and other tropical plants like canna, dahlia and gladiolus and dig up. Shaking soil from the roots, these roots can be saved in moistened peat in the basement after they are allowed to dry for a week. Some gardeners use perlite, vermiculite, newspapers, and some have had success just placing them in a paper bag.
I grew the most beautiful pot of vibrant red geraniums this year. Geraniums can be dug up and the plants can be placed in paper bag and kept in a cool dark location like you basement this winter. In March and April, pot up healthy plants an allow time for growth the resume.
Some annuals are heavy seed producers. Once they turn brown, they are mature and ready to harvest. Collect seeds from marigolds, zinnia, larkspur, and sunflowers. Allow them to dry down before you place seeds in envelop that should be stored in the refrigerator to ensure freshness.