5 ways to save cold-hating plants for another year
All those annuals, tropicals, and cold-hardy perennials you paid a lot of money for last spring will be blooming in another six weeks or so, once we get the first frost of the fall.
However, it is possible to save many of them for another season through five different plant storage or plant establishment options – known as “propagation” in biology.
Most of these techniques are easier than you think and worth the time and effort.
Even if you get a second year from just a little of your efforts, you’ve made a big dent in the plant’s budget.
Here’s a summary of the five options you can employ now and in the coming weeks:
1.) Tender plants that overwinter as houseplants. Many potted centerpieces, annual specimens and tropical plants grow well as houseplants indoors during the winter.
They may not bloom or look their best, but if you can keep the roots alive, they will usually bounce back outside next May.
Move the potted candidates indoors after hosing them down for insects. Plants in the ground should be dug up and placed in pots.
While you’re at it, consider moving your “real” houseplants outside as potted plants next summer. Most do well and appreciate spending a few months in outdoor air and moisture. Simply acclimatize them to the outdoors and move toward shady outdoor locations.
Also try putting in a few annuals now, such as pothos, coleus, lantana, begonia, and some tender herbs, such as rosemary and basil, for a sunny windowsill. These may not last the whole winter, but you can milk them for a few extra weeks indoors.
Good candidates for dual-duty plants: palms and New Zealand flax (phormium), T plant (Cordyline), century plant (Aloe vera), dracaena, elephant ears (Colocasia), citrus trees, ficus, tender fern, stromantheon, schefflera, papyrus, flowering maple (Abutilon), Jasmine, Begonia rex.
- Read more about houseplants as outdoor plants in the summer
2.) Suspended animation. Some tender plants go into “hibernation” in a freeze-free winter home, such as an unheated sunroom or basement. It is best to cut them into about a foot before storing them.
Dormant plants don’t need fertilizer or even much light…just a little water every now and then to keep the roots from drying out. Most of them will drop their leaves. Don’t worry. Remember, the goal is for roots to survive the winter, not foliage growth.
Next May, move the plants into the light, start watering and fertilizing, and within a few weeks, you should have a reborn survivor.
This works best with woody tropicals and thin shrubs. Good candidates: bougainvillea, mandevilla, dipladenia, allemandea, brugmansia, euphorbia, fuchsia, gardenia, tropical hibiscus, princess flower (let’s talk), Alternaria, Oleander, Salvia.
3.) Stored roots and tubers. Popular but winter-weakened species, such as cannas, dahlias and gladioli, will come back to life, even when you knock them down by the ankles and store only their underground parts inside.
Just before or after the first light frost, cut off the tender foliage, dig out the roots/tubers, and let them dry for a week or so. Then store them in slightly damp peat moss, sawdust, or perlite in a cool place (ideally in the 40s).
Some people store their tender bulbs/roots in a plastic or paper bag without any additional media.
The goal is to walk that fine line between keeping the roots/tubers moist enough so they don’t wilt but not so wet that they rot. Check regularly and adjust when early signs of problems appear.
Good candidates: cannas, callas, caladiums, dahlias, gladioli, bananas, elephant ears, tuberous begonias.
4.) Take cuttings. This involves making baby plants by coaxing cut ends from the mother plant to root.
Cut six-inch sections from the tips of branches, trim leaves from all but the top bunch or two, then pot the cuttings about two-thirds of the way down into pots of lightweight soilless mix.
A good mix is half coarse sand, half vermiculite, perlite, and/or lightweight potting mix. Keep the medium constantly moist, and within a few weeks, new roots should emerge from the buried nodes (where you pinched off the lower leaves).
If all goes well, these rooted cuttings will become “mother plants” that you can grow as houseplants next to a sunny window or under grow lights during the winter. Use them next year, or later in the winter, and start more cuttings from those plants to further multiply your flock in time for spring.
Good Candidates: Coleus, Geranium, Alternaria, Plectranthus, Ivy, Purple Heart (Secresia), Begonia, Lantana, Salvia, Tradescantia, Persian Shield.
- Watch George’s video on how to make new plants from cuttings
5.) Save seeds. Most important of all is collecting seeds from plants that are about to die. This applies to vegetables as well as annual flowers.
Look for seed heads or pods that are brown and ripe. Collect a few whole seed heads or press with your fingers to release the seeds into marked envelopes.
Dry the seeds if they have not already dried on the plant. Store in a cool, dry place. In a jar in the fridge is ideal.
Start seeds in late winter to early spring in a lightweight potting mix, just as you would with store-bought seeds.
Many seeds will also sprout if you scatter them outside on Mother’s Day.
- Read George’s column on how to sow flower and vegetable seeds directly outside
Since many of today’s best varieties are hybrids, you may not get exactly what you planted the year before. Some hybrids are even sterile. On the other hand, you may get something new and perhaps more interesting.
Good candidates: Marigolds, zinnias, larkspur, ageratum, alyssum, bractiantha, broalia, celosia, cleome, impatiens, nicotiana, petunias, portulaca, salvia, snapdragon, sunflower, gloriosa daisy, verbena, pepper (ornamental and edible), Tomatoes, peas, beans, watermelon and cucumber.
- Read more about how to start plants indoors from seed