Tropical Plants Far From Home

P80811+++++Plants can inhabit nearly every climate on Earth. They live in hot and dry deserts, cold arctic regions, rainforests and just about everywhere in between. Plants seem to have it all figured out. Some even know how to live in our homes as houseplants, although they probably did not plan it that way. Most houseplants are tropical plants that are naturally endemic to tropical ecosystems.

It is actually their tropical heritage that makes them more comfortable in our homes. Tropical climates tend to be conducive to proliferation of all kinds of plants. Those that want to live there must be competitive. Trees compete by growing faster and taller than other trees. Vines compete by climbing the trees. Understory plants that live under taller plants compete by needing less sunlight.

It is these understory plants that do not mind the shade of our homes. Even those that like bright ambient light might never expect to get direct sun exposure. The various ficus trees that might naturally grow tall enough to reach the top of a forest canopy in the wild are still understory plants while young. Because they know how to use resources efficiently, tropical plants do well in pots.

However, these advantages are not so useful out in the garden. Tolerance to partial shade also means that some tropical understory plants need to be sheltered. If too exposed, foliage can get roasted by sunlight or arid wind. (Most tropical climates are more humid than local climates are.) Complaisant roots do not disperse well enough to sustain lush foliage without regular watering.

Ironically, roots of the various ficus trees are very aggressive because they to not disperse deeply, but instead spread out at the surface of the soil where they grow into exposed root buttresses.

The most familiar weakness of tropical plants is their susceptibility to frost. Even though it does not get very cold here, it gets cool enough in winter to offend plants that would never experience cool weather in the wild. Actual frost can severely damage foliage, and can even kill some tropical plants.

Mother In Law Tongue

61116What an unflattering name for such striking tropical foliage! The pointed and strap-shaped evergreen leaves of mother-in-law’s tongue, Sansevieria trifasciata, stand vertically, about two or three feet tall. They are rather rigid, and seem to be plastic with a glossy finish. Almost all modern varieties are variegated with silvery gray, white, cream or yellow stripes or banding. Dwarf varieties stay shorter, with flared foliage.

Because it tolerates shade and neglect so well, mother-in-law’s tongue has always been a popular houseplant. It is sometimes grown in pots outside where it can be sheltered from frost or direct sunlight that might roast the foliage. Pups can be divided from overgrown old plants, but will develop shorter leaves until they recover from separation. Crowded plants might get green sports (unvariegated mutant shoots).

Even Houseplants Can Appreciate Rain

P71116Everyone is from somewhere. Not everyone is fortunate enough to be from California. Most of the various plants in our gardens, even if grown locally, are descendants of plants that were collected from all over the world. Most houseplants are from tropical regions. They perform well as houseplants primarily because they tolerate the sort of partial shade that they would get as understory plants in dense tropical forests.

Along with this advantage of tolerance to shade, tropical houseplants come with other disadvantages, such as an intolerance to frost. So, they are able to live inside the home, but are unable to live very long outside where winters are cool. Even areas of Southern California that do not get frosty can get cool enough to make many tropical houseplants uncomfortable. Consequently, they are confined to their homes.

That might seem to be acceptable to those who not think like plants do. Really, do houseplants even want to go outside? Maybe not. However, shelter from frost and cool weather also shelters them from other weather, such as wind and rain. Without wind and rain, any dust that collects on the foliage stays there. Mealybug and scale insects can proliferate and produce sticky honeydew, which also will not rinse away.

This is why some of us like to occasionally put our houseplants in a cool shower to rinse them off. It eliminates much of the dust, and clears out the stomata (respiratory pores). It does not kill mealybug or scale, but sets them back a bit, and rinses off the honeydew. Showering is also a good way to soak and rinse toxins from the soil. Only African violets, gloxinias and a few plants with fuzzy foliage should not be showered.

The only thing that works better than showering is rain. (Remember that wet stuff that starts to fall from the sky this time of year?) Rain is gentler, lasts longer than a shower, and is located outside where the mess of wet houseplants is not so bothersome. The only disadvantages of rain are that it can be cold, and is often accompanied by wind. A slight breeze would help agitate dirty foliage and dislodge dust, but strong gusts can knock houseplants over, and damage large leaves that are not adapted to any wind. Plants should be sheltered from both wind and direct sun exposure that might happen if the plants are not brought in before clouds clear after the rain.

The Coffee Shoppe That Grows Its Own

P70928There are certain things that we expect to find in a coffee shoppe. Mainly, we expect to find . . . coffee. Yes, coffee, . . . duh. We can get all sorts of coffee beverages; hot, chilled, steamed, infused with things that have no business going into coffee. They have all sorts of cool sounding but strangely irrelevant Italian names that white people enjoy telling people of Italian descent how to pronounce. Yes, my name is Tony Tomeo; and I don’t want twenty cups of coffee with bread. Well, besides the coffee beverages, there are plenty of coffee beans; all sorts of roasts. I do not know of any coffee shoppe that grows any of the beans that it sells, but there is nice coffee shoppe in Felton, The Mountain Roasting Company, that grows coffee trees.

Yes, that is unique. I noticed a few years ago that besides the typical Ficus benjamina, there are three large coffee trees. They look similar to the Ficus benjamina, but are a bit less refined, and lack the braided trunks. They grow up to the ceiling before getting cut back to stumps to start the process all over again. The Ficus benjamina do not grow that well; but the coffee trees are happy enough to bloom there.

I have not asked how they get pollinated. I really do not know how coffee flowers get pollinated in the wild. Somehow, they make a few fruits, known as coffee cherries, with viable coffee beans inside. The seeds get collected, germinated, and potted for customers who have an appreciation for growing something unique. Small coffee trees can now be found in well outfitted nurseries, but it would be so much cooler to grow one that was grown at a local coffee shoppe.

I am embarrassed to say that I do not know how to grow coffee trees. I think of them as tropical plants, but I really do not know. Just because they are cultivated closer to the tropics does not mean that they originated there. I do believe that they are understory trees, that prefer to live in the partial shade of larger trees. Old text, as well as a few not so old gardening books from the 1960s, describe them as houseplants. There is not much mention of them after that. They only recently started appearing in nurseries. I like when old traditional plants make a comeback, particularly if it happens to be an alternative to a boringly common plant like Ficus benjamina.

Wandering Jew

70927It could not have survived out in the desert for forty years. Wandering Jew, Tradescantia fluminensis, would have desiccated before its first summer. Well watered gardens are a completely different situation. Wandering Jew can become invasive and mix with other more desirable ground covers, only to die back and turn dark brown through winter. It starts over the following spring.

The one or two inch long leaves and succulent stems are very tender, sort of like busy Lizzie (impatiens). Stems root wherever the swollen nodes touch moist soil. New plants are ridiculously easy to propagate by cuttings, or simply by scattering pruning scraps wherever new plants are desired, and sprinkling a bit of soil or compost over them. Because it is so tolerant of shade, wandering Jew is an easy cascading houseplant. A variegated cultivar has slightly larger leaves.

Houseplants Bring The Outdoors In

70927thumbPhilodendrons, dracaenas, ferns, palms or any sort of tropical foliage inside our homes only create an illusion of closeness to nature. Naturally, these plants live in very different climates, mostly thousands of miles away. Not only do they have no business in our homes; they have no business on the North American Continent. Some can live in the garden, but only with unnatural watering.

They are only known as houseplants because they ‘can’ live in the house. Almost all are from tropical regions; and most are understory plants that naturally live in the shade of larger trees. They work nicely as houseplants because they tolerate the shade of home interiors. Because they are from tropical regions, they have no concept of winter, so do not need chilling for winter dormancy.

The disadvantages to their tropical heritage is that they are confined to domestic lifestyles here. Many would not survive frosty winter weather. Some might survive, but would not be happy about it. Others would not like the aridity (lack of humidity) during the summer. Houseplants that get moved out to the garden for part of the year must be grown in pots so that they can be moved back in.

While inside, there are no natural predators to control the insects that feed on houseplants. Scale and mealybug can proliferate enough to not only damage houseplants, but to also make a mess of their sticky honeydew below the houseplants they infest. Spider mites can proliferate where dust accumulates on foliage. That is why houseplants sometimes like to be rinsed by a gentle rain.

Since they are confined to pots, houseplants must be watered more carefully than plants that get to disperse their roots out in the garden. Some large Boston ferns and spider plants may need quite a bit of water to be applied very regularly. Some dracaenas, palms and ficus trees may want to get slightly dry between watering. As soil deteriorates, old plants might need to be repotted.

Houseplants are grown for their lush evergreen foliage, and such lush foliage can be sensitive to fertilizer toxicity. Even if fertilizer is applied lightly, toxins can eventually accumulate if fertilizer is applied very regularly. This problem is usually corrected with repotting. However, plants that never need to be repotted might like to be taken outside to get water rinsed through their potting soil.