A Guide to Bringing Outdoor Plants Inside

I own a wholesale nursery in Long Island, New York, and every fall I am asked the same urgent questions: Which plants can I bring inside? Will this one make it through the winter on my windowsill? Is there any way to save this one for next year? Believe me, I can sympathize. After a spring and summer spent lovingly cultivating my garden, I like to keep as much of it alive as possible, and deciding which plants to bring inside and which ones to leave to their fate can be a complicated matter. So I’ve developed a few rules of thumb.

Left: Clerodendrum. Both the vining and shrub forms make good houseplants when given plenty of light and kept evenly moist.

Here: 'Blue Wings,' (C. ugandense).

Dennis Schrader is co-owner of Landcraft Environments in Long Island, New York.

First, make peace with the fact that some plants are just not meant to be brought into the house, period. There’s no point in trying to prolong the life of true annuals such as marigolds, zinnias, and nicotiana indoors. Once they bloom and set seed, these plants are preordained to die, always with the hopeful promise that the seed they produce will germinate next season. (See 'Toss These Plants' on slide 10)

Left: Abutilon Commonly called flowering maple or parlor maple, this plant, popular since Victorian times, will bloom all winter as long as it is positioned in a bright, cool, sunny window.

Here: A. x hybridum ‘Clementine.’

Other plants, by contrast, are well-known for their ability to make the transition indoors. You should fully expect that your geraniums, coleus, and begonias will bloom and perform all winter if placed on a sunny windowsill.

Many of the tender perennials we now consider annuals originally found their place in horticulture as houseplants; accordingly, these garden mainstays are also excellent candidates for bringing inside.

Left: Coleus Easy to root and can be kept growing in a glass of water, coleus like bright light. It's best to remove flower buds as soon as they appear.

Here: C. 'Inky Fingers' (top), C. 'Smallwood's Orange' (right),  C. 'Dragon Tongue' (left).

Among these is alternanthera, which actually requires the short days of winter to induce its sequence of blooms — so haul it on in.

Left: Alternanthera This mainstay for foliage color in summer plantings also makes a great houseplant blooming in early winter with white flowers, giving it the common name of Christmas clover. 

Here: A. dentata ‘Party Time.'

Still other plants, like hibiscus, clerodendrum, and pelargonium, will simply continue performing as if it’s the Fourth of July, regardless of the fact that there’s 6 feet of snow on the ground outside.

Plants like these — including some of the specimens pictured in this slide show — will reward you with color and fragrance during winter and can be returned in spring to grace your garden beds once more. 

Left: Hibiscus In a sunny location, tropical hibiscus will do very well indoors. It may go through a leaf drop and require some pruning, but the plant will recover quickly. Watch for aphids.

Here: H. ‘Gypsy Music.’

Then there are the special cases. Sometimes I find that rare gem-of-a-plant I’ve been coveting for many years, and I know if I leave it out to freeze, I may never be able to replace it — so in it comes.

Be true to your heart, but remember to set limits. I know lots of people who have beautiful, well-edited gardens but whose houses in winter are cluttered jungles.

Left: Pelargonium Varieties of this hardy plant like it sunny and dry between waterings and will continue to bloom all winter. Its fragrant foliage is an added pleasure.

Clockwise from top: P. reniforme, P. sidoides, P. 'Lady Plymouth.'

Learn more about growing geraniums.

So, before you drag everything in, think about your own living space, not just for your own comfort but for the plants' sakes. Even the most rugged outdoor container plant will suffer indoors without the right amount of sunlight, air circulation, and drainage.

Left: Solanum jasminoides Variegated potato vine (S. jasminoides ‘Variegata’) makes a nice trailing plant to hang in a bright window where it will bloom in late winter with an abundance of pure white flowers.

Follow a few basic rules: Before you carry that pot inside, check for pests (especially slugs hidden in the drainage holes). Repot the plant if necessary. Also, think of your friends in the animal kingdom; some common plants, such as cutleaf philodendron, asparagus fern, and even aloe, can be toxic to pets.

Left: Tradescantia Common in gardens and indoors, varieties of this plant prefer bright light and to be kept evenly moist.

Here: T. ‘Golden Oyster’ (top) and T. ‘Tricolor’ (bottom).

Finally, if space is limited, there are alternatives to creating an impenetrable jungle in front of every window: Collect seeds, cuttings, and bulbs for next season, or keep plants dormant in a cool, dark, out-of-the-way place where they won't compete for air and light. You'll develop a sense of what works and what doesn't, and you'll be able to enjoy the pleasures of your garden year-round.

Left: Begonia Just about every type of begonia can be brought inside and enjoyed throughout the winter months, as long as they have bright light and are allowed to dry out slightly between waterings.

Here: B. maculata var. ‘Wightii.'

Toss These Plants

Some annuals should not be kept through winter, such as those that don't do well inside or that are easy to find. Here's a list of plants I suggest tossing:

1. Angelonia

2. Bacopa

3. Cuphea

4. Fuchsia

5. Helichrysum

6. Ipomoea

7. Lantana

8. Marigold

9. Petunia

10. Salvia

11. Torenia

12. Verbena

Left: Acanthus Its spiny leaves provide an interesting architectural element in containers. When brought inside Acanthus montanus blooms in midwinter with long-lasting, tall spires of white flowers that fade to dusty rose.