It’s Getting Cold Out, So Garden Indoors

The leaves are falling, but you don’t have to sink into winter doldrums. You can keep up your green thumb and all the joy you get from growing with indoor plants. All that greenery inside your house is much more cheerful than the brown landscape and bare trees outside. So fill your home with green and flowers.

geranium and houseplants on table.
Fall is the time to bring geraniums, succulents and other houseplants indoors — and then find a spot for them!

Here are a few ideas on how to extend the season and ease into winter slowly.

Adjust houseplant conditions

Even houseplants that live indoors all year might need some winter preparation. This includes cutting back on watering and fertilizing and cleaning leaves to allow as much light as possible to reach the plant. Because winter days are shorter, and the sun in the northern hemisphere is lower, you might have to move plants to different windows or supplement their light with grow lights. And be sure not to overwater houseplants in winter. Most need a break to rest, and only need water when the soil dries out.

succulent arrangement
These succulents spend winter indoors near a warm wall and sunny window. We can move them around as the sun moves up or down in the southern sky.

Move container plants inside

We move inside any plant we love and think can make it at least a few months inside. It helps if it is not too heavy to move. This includes many succulents that can’t take low temperatures, geraniums, and plants that tolerate shade. We had a gorgeous coleus container we brought inside one year. It got leggy, but we were able to enjoy it for a few months more than if we had discarded it.

barrel cactus and aloe in containers
Most of our succulents can’t handle the cold winter lows in zone 6B, so they come inside for winter.

Harvest or grow edibles

Pick green tomatoes if still viable on the vine and let them ripen indoors, fry them up or make a tomato sauce starter. Making pesto is fun, but you also can cut basil branches and place in a jar of water for extended life. If canning is your thing, it feels good to prep for winter by preserving fruits and vegetables. When you miss your summer garden, visit the dark cool area where the jars of your preserved crops are stored. You can grow sprouts in glass jars to “summer up” sandwiches and salads.

herb garden vertical
This sunny room in my daughter’s house is perfect for houseplants and herbs.
chives and basil in window
You can extend the season for some herbs inside. Or look for lights and systems that help you grow herbs and microgreens all year.

Take cuttings of favorite plants

That coleus that got too big and lanky? We could have rooted new coleus plants from cuttings instead of bringing the mature plant inside. There’s a fun indoor project! In fact, try taking cuttings of favorite plants and starting them indoors. Not all plants are easy to propagate, but with some practice, you can start your own plants for the next spring.

Succulents often bloom in winter and early spring, adding color to your indoor gardens.

Buy a new houseplant

African violets can bloom almost continuously if they receive enough sun and consistent, light moisture and repotting as needed. There are thousands of varieties with different bloom colors and styles and variegated leaves. Many succulents bloom in winter (such as Christmas cactus) or in spring, when you’re really itching to get outside and grow. Both succulents and African violets also are easy to grow from leaf cuttings, though the technique is very different for each.

violet succulent
African violets and succulents are easy to start from cuttings.

A Trip to the Dark Side of Gardening

datura bloom
Datura, or Jimson weed bloom.

When we write about gardening and post on social media, garden writers usually choose bright, pretty pink flowers or robust tomatoes as our subjects. Yet, many plant lovers can enjoy flowers and also get a kick out of growing edgier plants.

I live with one such plant lover. In fact, he loves spines and poisonous seeds so much that our daughter and son-in-law gave him Amy Stewart’s book Wicked Plants, The Weed That Killed Lincoln’s Mother & Other Botanical Atrocities (Algonquin Books, 2009) for Christmas last year. He likes to read it right before nodding off at night…

jimson weed plant
Jimson weed is not a pretty plant but the flowers are gorgeous, especially for an evening garden.

I thought I’d share with you some of Stewart’s insights into wicked plants, and list several that thrive in our entryway or rock garden.

Datura and Nightshades

Several deadly plants make up the nightshade, or Solanaceae, family. The one we grow every year (it comes back with a vengeance) is Jimson weed, or Datura stramonium. The entire plant is somewhat poisonous, but the real danger lies in the seeds inside the fruit pod that remains after the flowers fade.

datura seed
The seed head of a Datura.

I admit I love the flowers and watching hummingbird moths feed off the blooms, which open at dusk. According to Stewart, Jamestown colonists found out the hard way about the toxic alkaloids in Jimson weed. In fact, the name has evolved from its original moniker of “Jamestown weed.” The Jimson weed is the dry cousin of other toxic nightshades and grows naturally in some of the worst conditions of the desert Southwest.

angels trumpet flower
Angel’s trumpet flower in a Pasadena garden.

Castor Bean

Castor bean (Ricinus communis) is a member of the Euphorbiaceae family. It’s known for the ricin in the plant’s beans. Eating only a few of the seeds can kill a person. Like the Jimson weed, the toxic beans grow on an otherwise gorgeous plant. In full sun, we’ve had them shoot from seed to 10 feet tall in a summer growing season. The large leaves of the plants we’ve grown turn a dark bronze color. Also like the Jimson weed, the fruit can explode when dried out and scatter the toxic seeds. if you decide to plant this potentially deadly ornamental, you must remain vigilant about cutting off the fruit. I don’t have photos of our castor beans, probably because I keep a distance. But here is a link to more information and some excellent images of the plant and beans.

crown of thorns and pencil cholla
Crown of thorns and a pencil cholla add a little danger to our home’s hallway.

Spiny Euphorbias

The spinier and spikier, the better for our sunny hallway. Relatives of the castor bean in the spurge family include the lovely Crown of Thorns (Euphorbia milii). It also has a sticky, white sap called latex that can irritate the skin. I can’t imagine any animal chomping on the thorny branches, but I’ve seen deer eat rose branches, so it’s good to make sure dogs don’t eat the euphorbia. Euphorbias also include poinsettias, which are not truly poisonous, but can cause irritation if the toxins from leaves contact your eyes or stomach problems if children or pets eat the leaves.

larkspur plants in rock garden
Larkspur plants that reseeded and bloomed in early summer.

Larkspur

Stewart includes larkspur among her “Dreadful Bouquet” flowers. Larkspur is a member of the Delphinium family, and sometimes, the names are interchangeable. Plains larkspur plants are found throughout high plains of New Mexico, Colorado and Wyoming. The plant has dangerous levels of alkaloids in seeds, flowers, sap and leaves and can lead to death in cattle who consume the plains flowers at and after flowering. I love the early spring blooms of larkspur, which reseed between rocks in our garden and took over most of a bed last year. I’ve never seen deer damage, and as long as I wear gloves when handling the plant and avoid taking bites of it, I’m good.

pink and violet larkspurs
I wear gloves when I tend to these pretty Larkspurs.

Oleanders

Oleanders are popular shrubs and hedges in warmer Southwest climates (zones 8 through 10). They have long, slender leaves and colorful flowers. Because the plants grow quickly and need little care, they’re popular choices in landscapes. The plant’s sticky sap carries several toxins, including oleandrin, which can cause nausea and vomiting and affect heartbeat. People have been known to commit suicide by eating the plant, but the main concern is to keep curious children away, since it takes eating less to make them seriously ill. It’s too cold here to grow oleander, but we have a beautiful cousin of the plant that has a similar milky sap, a Desert Rose (Adenium), that we keep as a houseplant in winter.

Adenium with blooms
The desert rose, or Adenium, is a cousin of the oleander bush.

Poppies

The poppy (Papaveraceae) is a favorite Southwest plant. Many species of poppies have toxins that can hurt animals. After all, Papaver Somniferum is the plant that supplies opium. The opium poppy is illegal to grow, but seldom regulated, says Stewart. That’s largely because of how many plants it would take to supply an individual with enough opium to maintain a habit. Our poppies have spiky leaves that distinguish them from the smoother foliage of an opium poppy.

white Oriental poppy flower
A white Oriental poppy bloom.

Other Common but Wicked Plants

Stewart’s book breaks down dangerous plants by plant families and other categories, such as phototoxic plants. These have sap that can burn the skin when exposed to light and include the rinds of limes and other citrus fruits.

Lobelia plant in top of container
Lobelia is an annual here with small, delicate flowers like those I placed in the top of this tiny chiminea.

One of our favorite summer annuals is Lobelia, which also is called Indian tobacco because some ingredients in the plants cause effects similar to nicotine. In small amounts, lobelia can’t hurt you, but it can be toxic in large doses if used as an herbal remedy. I also love, love, the red bird of paradise, another warm climate ornamental shrub. But Even sweet peas and tulips have toxins in various parts of the plants or bulbs.

red bird of paradise bloom
The gorgeous, fiery bloom of a red bird of paradise.

The bottom line is this: All gardeners should use caution when choosing plants for their home or garden to make sure curious pets and children are safe (this is an extensive list of both, and toxicity ratings, from California Poison Control). On the other hand, growing a spiny or dangerous plant can appeal to adults and older children, and be a great introduction into plant care and the gardening bug!