9 Perennials that Make Great Houseplants, Too

Plants you can grow indoors and out

It is wonderful to have potted plants on the porch or patio, providing splashes of color that are neatly contained and that you can rearrange if you wish. But what if, instead of letting the frost kill those pretty plants, you brought them indoors? They might be as lovely indoors as out. And, if you remember to water them properly, you can set them outside again when it warms in the spring. Or buy plants now and plan to put them, in their pots, outdoors in the spring. Here are a few plants that do well both indoors and out.

Hydrangea, Hydrangea species. Both mop head and lace cap (macrophylla) hydrangeas will thrive in a pot that goes indoors. Choose a dwarf variety; don’t try to force a big plant to grow well in a small pot. Keep hydrangeas cool—not cold—during the winter months. Put plenty of compost in the pot and keep it moist. Mist the leaves occasionally. Give the plants bright light but not direct sunlight. And enjoy!


SHOP FOR HYDRANGEA

Calla Lily, Zantedeschia procumbens. Calla lilies have beautiful flowers and attractive foliage. Give calla lilies rich soil with lots of compost. Keep the pot continuously moist. In nature calla lilies live on the edges of ponds, so when growing well, they enjoy saturated soils. But as their growth slows, especially indoors, make sure the pot drains well so the roots don’t stand in water. Provide bright light but not direct sunlight. Add liquid fertilizer monthly while flowering. Calla lilies will go dormant after flowering. Store the bulb in slightly moist peat in a cool dark area until shoots reappear.

Plumbago, Ceratostigma plumbaginoides. Plumbagos will produce their lovely pale blue or white flowers as indoor plants. Put the pots in a room with average to cool temperatures (45°F is good) in a sunny window. Keep the plants moist but water sparingly. Plumbagos tend to sprawl; tie up dangling branches if you don’t like the look.

Roses, Rosa species. Roses make terrific house plants. But don’t try to grow a standard rose bush in a small flowerpot; get a miniature rose variety. Choose one listed as reaching 12” or less that is recommended for pots. Give the little rose ordinary indoor winter temperatures (50-70°F). Provide a lot of light, for example, put it on a sunny windowsill. You may want to add a few hours of light (fluorescent or a grow light) when the winter days are particularly short. Water liberally but allow the pot to nearly dry out between waterings. Provide humidity in the dry winter months: putting the pot over a tray of pebbles, keeping water on the pebbles, will create a good humidity. Mist frequently. Remove faded blooms to extend flowering. Outdoors a potted rose will need little care; indoors, pay attention to light and humidity or it won’t flourish.


SHOP FOR ROSES

Dianthus. Carnations, pinks, and sweet Williams are all species in the genus Dianthus. Annual dianthus species do not do well indoors, but perennials like carnations and sweet Williams can be successfully brought in, then returned to the outdoors in the spring. Dwarf varieties are particularly nice in pots. When grown indoors dianthuses need cool conditions, 50-60°F, and bright light, but not direct midday sun. Always keep the soil and compost in the pot moist but don’t overwater. Mist the leaves occasionally. Enjoy the lovely flowers.

Hibiscus, Hibiscus species. Hibiscuses grow well in pots and flower for months. With care, plants can live for 20 years, going in and out with the seasons. Indoors they need average temperatures (70°F) and as much light as possible, but shade from direct hot sun. Water sparingly in winter but keep the soil, rich in compost, moist always. Mist the leaves occasionally to raise humidity. If you let them dry out, you might see bud drop, leaf curling, or leaf drop. Buy a miniature hibiscus, don’t try to work with a standard variety. There are many wonderful miniature hibiscus varieties available, for example of Chinese hibiscus H. rosa-sinensis and tropical hibiscus H. schizopetalus. You can have their beautiful flowers opening in your living room.

Caladium, Caladium species. This tropical plant has terrific arrow-shaped leaves in glorious colors. Keep it warm—above 70°F—and never let the room temperature drop below 60oF. Provide good light but don’t place it in direct sunlight. Water freely and mist the leaves frequently. Some varieties will go dormant; if so, reduce water and let the tubers rest in the dark at 50-60°F (not colder) until they send up new shoots.


SHOP FOR CALADIUM

Wintergreen, Gaultheria procumbent. This is a handsome native with glossy green (or variegated) leaves, white flowers, and large round pink to red, edible berries. The leaves release the lovely wintergreen fragrance when bruised. The leaves tend to drape gracefully over the edges of a flowerpot. Easy to grow, put wintergreen in a bright but not sunny spot; this is a great plant for indoors spots because it can tolerate at most 2 hours of direct sunlight, and that only early or late in the day. Provide well-draining organic-rich soil, such as potting compost. Keep the soil pH slightly acidic, preferably lower than 6.5. Add a little organic fertilizer at least once a year. Mist the leaves periodically. The temperatures should be 60-70°F, easy in my house in winter. They’re beautiful!

Violets and Pansies, Viola species. Violets, pansies, johnny-jump-ups, heartsease, and violas are all in the genus Viola, tough little plants with colorful flowers. Just as you can buy flowering pansies to put out in early spring, you can bring in flowering pansies and keep them flowering indoors. Pinch off spent flowers. Give them hours of bright sunlight but keep the room temperatures average (70°F). Add fertilizer periodically to maintain flowering. Water well but keep well-drained. Pinch off the edible flowers to garnish salads.

General advice:

  • Light: Pay attention to where the plant was growing outdoors and where you plan to put it. The transition from outdoors to indoors or vice versa will be more successful if the hours of sunlight are similar in both places. Many plants can live in both shade or full sun, but must replace all their leaves if the light changes radically. Avoid shocking your plant that badly.
  • Soil: Be sure they are potted in a potting soil with lots of compost; that holds water far better than soils with less organic matter and, simultaneously, provides nutrients.
  • Temperature: If the temperature is wrong, plants may survive but not grow or flower. Put the pot into a location where the temperatures are what it likes.

Things to watch for if the plants don’t look well:

  • Drafts. The room may be warm but are there blasts of cold air each time the door opens? Conversely, hot air drafts coming out of the heating vents can severely stress plants.
  • Underwatering: Most of these plants should not be allowed to dry out. A pot has a very limited water-holding capacity compared to being planted outdoors in the ground, so when the water is gone the plant has no resources. Keep it moist.
  • Overwatering: When soil is saturated, it can hold no air. Roots need the tiny air pockets in the soil to exchange gases as they grow; in water-filled soils they suffocate. Make sure the pot is well-drained. (Yes, having underwatering and overwatering both as concerns seems contradictory, but a plant in an indoor flowerpot is trying to grow in a very limited space managed by humans; we need to be attentive.)
  • Inadequate Light: Even windows that are very bright in midsummer can provide little light in winter when the days are short or it may be frequently overcast. Consider supplementing the light with fluorescent lights or full spectrum plant lights, especially, extending the hours of daylight during midwinter.
  • Animals in pots: Moving pots from the outdoors can bring in animals, from lizards to ants, which were living in your pot when it was outdoors. Check the plants for animals before moving the pot and remove them. To further reduce surprises, move the plant in in stages, say, after sitting two or three days on an open porch, before putting them in the dining room. The residents will likely move out or at least become obvious, in which case, repot the plant.
  • Pests: outdoors, pests like spider mites and aphids are generally controlled by their predators. Indoors, these pests can build up. Check the plants regularly and take action, for example, physically removing them or applying mild alcohol or an insecticidal soap, before they get very numerous.

Try these wonderful plants for year-round beauty.

Written by Kathy Keeler, AWanderingBotanist.com