houseplants – Page 2

House Plant Reboot

If your houseplants could talk, they would tell you that they like natural daylight—the kind you get outdoors—better than artificial light of any kind. They might also say that the winter-time humidity level in your house is too low. They hope that the compensatory misting you give them does something good for you, because it doesn’t help them very much. Neither does the overwatering that they get from time to time. In the midst of saying those things, some of them might yawn, as winter is a time when many houseplants’ growth cycle slows.

What do your plants want in the winter? The following will help keep them in good shape until spring sets in and growth cycles start anew.

Tidying Up

Anthurium 'A4' (PACORA™) PP11728 — Wipe down the leaves of large-leaved plants, such as this *Anthurium*, if they become dingy or dusty. (Jessie Keith)

Your plants, especially those that have summered outside, probably could use a little TLC. Prune out weak stems, and cut back those that are too gangly. If the plant has glossy leaves, like a gardenia, gently wipe the foliage with a damp cloth to eliminate pore-clogging dust. Check stems, leaves, root ball for pests. Many can be dislodged with a stream of water or application of insecticidal soap. If the plant is pot bound, repot with fresh media, like Fafard® Professional Potting Mix, in a clean container that is about one third larger than its predecessor. Winter will not bring much growth, but it won’t bring strangulation either.

Light

Clivia are midwinter bloomers that need bright indirect light for good flowering. (Jessie Keith)

If you are blessed with a lighted greenhouse, all you have to do is find appropriate spaces for houseplants that prefer a bit of shade. But if you, like many gardeners, have to rely on windowsills, try to put most of your plants in south-facing ones. This may be too much for some popular indoor varieties, like African violets or fancy-leaf begonias. Save areas with bright indirect light, like north-facing windows for them. Be sure to rotate your houseplants regularly to even out light exposure and avoid lopsided growth.

Fertilizer

In general, fertilize plants when they are in active growth. For most plants this means little or no feeding in late fall and winter. The caveat is that you should know your plant. If it is a winter bloomer, it may need fertilizer during the colder months. A little research on individual species will ensure that you fertilize properly for winter blooms.

Humidity

Calathea lancifolia — Low humidity caused the leaf edges of this Calathea to turn brown and dry. (Jessie Keith)

Houseplants like more humidity—generally 40-50 percent— than the average indoor environment provides in winter. If all your plants are in a single room, think about investing in a humidifier. The added moisture in the air will be good for you, the plants and any wooden furniture in the immediate area. If a humidifier is not an option, fill deep plant saucers with pebbles and water and stand the plants on them, making sure that the bottoms of the pots are not standing in water. Replenish the water around the pebbles every few days or as needed. If plants are grouped together and each stands on a bed of pebbles and water, the humidity level around them will be comfortably high.

Watering

Agave victoriae-reginae 'Variegata' — Succulents, such as this variegated *Agave*, need very little water in the winter months. (Jessie Keith)

Overwatering is the most frequent cause of houseplant death. Fortunately, it is also the most preventable. Before you water, take a look at the plant. Is the top inch of the soil dry to the touch? If you pick up the container, does it feel relatively heavy or light? If the specimen in question is a succulent, it is best to water them very sparingly in winter. If your plant appears to be too dry, gently feel a leaf or two. Thirsty succulents tend to have slightly flaccid leaves.

If the plant is dry, water thoroughly until water flows out of the holes in the bottom. Deep watering once or twice a week in the winter is much better for overall health than adding a little water every day. Some houseplants, such as African violets and Streptocarpus, need to be watered from the bottom to keep their leaves from getting wet; moisture on the leaves causes spotting and damage.

Temperature

Pilea cadierei JaKMPM — Tropical plants like this *Pilea* need warm temperatures to grow well indoors. (Jessie Keith)

The majority of popular houseplants like the same indoor temperatures as the majority of humans. Like us, they also prefer to avoid extremes. Ambient temperature around 70 degrees F is generally good. If you house your plants on windowsills, don’t let leaves touch the cold glass panes. Avoid positioning them over radiators too. Intermittent cold drafts from doors, windows or vents can also be harmful.

Languishing

Kalanchoe blossfeldiana JaKMPM — Flowering potted plants may languish when you first bring them indoors for winter. Give them good care and they should revive. (Jessie Keith)

In late fall or early winter, houseplants that have spent the summer and early fall outdoors often languish while adjusting to lower light, less humidity and fewer daylight hours. If the plant is in the right light situation and receiving adequate water, it will adapt and recover after a few weeks. That does not mean that your plumbago or oleander or prize geranium will behave like the blooming fool that it was in the summer. It means that it will live to dazzle you again when warm weather returns.

The same may hold true with houseplants that you purchase from a nursery, garden center or other retailers. Many have been raised under near-ideal conditions and will need adjustment time as they get used to your particular indoor environment.
Houseplant care follows the same rules as care of any other kind of plant. If you are observant, the plant will generally tell you what it needs. Watch for signals and respond accordingly. If the soil is too wet, cut back on watering. If leaves appear burned around the edges, move the plant to a place with less light. About the time you are feeling droopy due to winter blues, your plants may be similarly afflicted. If you have given them good care, both you and the plants will recover as the hours of daylight increase.

Streptocarpus are houseplants that should be watered from the bottom and kept just moist in winter, never wet.

South African Bulbs for Indoor Growing

*Lachenalia aloides* var. *quadricolor* is beautiful and flamboyant.

Most Cape bulbs follow the seasonal rhythms of their native land, beginning to push leaves in late summer or fall (whether watered or not), and flowering at their appointed time in late fall, winter, or early spring. Their flowers also tend to share a certain likeness, with many species bearing heads of narrow, tubular, brightly colored blooms on stout scapes – the better to attract and accommodate the long-billed, brilliantly hued sunbirds that pollinate them.

Cape Hyacinth

Veltheimia bracteata (commonly known as forest lily or cape hyacinth) beautifully exemplifies these Cape bulb traits. Handsome in their own right, the lustrous, wavy-edged, strap-shaped leaves (with perky wavy-edged margins) emerge from fleshy, tennis-ball-sized bulbs in late summer. In midwinter, red-hot-poker heads of tubular pink flowers develop on fleshy purple-flushed scapes that slowly elongate to 18 inches or so. Flowering peaks about Valentine’s Day, but continues for several weeks before and after. An almost indestructible house plant, Veltheimia bracteata thrives in bright indirect light, relatively tight quarters, and a porous potting mix (such as Fafard® Professional Potting Mix with RESiLIENCE). Shallow planting (with the “shoulders” exposed) suits the bulbs well. Plants prefer a dry, shady summer rest after the foliage begins to flag in late spring.

Lachenalia

Showy, tubular blooms also make a frequent appearance in the genus Lachenalia. Lachenalia aloides is perhaps the most flamboyant, flaunting proportionately large golden-orange blooms that nod on 10-inch scapes in mid- to late winter. Some forms of this species take the flamboyance one step further, adding horizontal bands of crimson, yellow, purple, and green to the floral color scheme. Variety quadricolor is one such dazzler, with orange-based blooms that shade to yellow at their midriffs and purple-red at their tips. Flowers of the cultivar ‘Nelsonii’ have brilliant red buds that turn lemon-yellow with lime-green tips as they expand. Purple splotches ornament its stems and leaves, another characteristic of many forms of this striking species. Other highly ornamental species include Lachenalia bulbifera, with lipstick-red flowers that open around Christmas, and Lachenalia rubida, whose freckled, rose-pink, late fall blooms are the earliest in the genus. Lachenalia hybrids are also now available, most notably in the form of the African Beauty Series (including ‘Namakwa’, ‘Rupert’, and ‘Romaud’).
All of the above lachenalias prosper in containers. Shallow planting (one inch deep or so) in a porous potting mix is best, with moderate watering during the growing season. Lachenalias like it cool and sunny while in growth but should be moved to a dry, shady location when dormant.

Lachenalia fanciers often find themselves drawn to the many species that flower in less gaudy but equally seductive hues (sometimes with fragrance thrown in). The flowers of Lachenalia viridiflora, for example, are of a luminous, other-worldly turquoise-green, making for a singular late fall to early winter display. These lesser-known and lesser-grown Lachenalia species can be somewhat tricky in cultivation, but all are worth the effort.

Haemanthus

Not all Cape bulbs fit the tubular mold. Haemanthus albiflos is a striking example, brandishing white, up-facing shaving-brush flowers on short fleshy stems in fall or early winter. The leathery, tongue-shaped, evergreen leaves are also attractive. This drought-tolerant species is practically indestructible if shallowly planted in a porous potting mix in a bright but not too warm location.

Oxalis

North American gardeners tend to think of Oxalis species (commonly known as wood sorrel) as horticultural thugs. Many Cape Oxalis, however, are of a far more rarified (and less invasive) plane, featuring jewel-like flowers and lush, ornamental foliage. Oxalis purpurea deserves a place on every cool sunny windowsill in need of winter color. Its numerous varieties flower in a rainbow of colors, from white to rose-pink to raspberry-red to lemon-yellow, and its rich green “shamrock” leaves are sometimes suffused or blotched with contrasting colors. The cultivar ‘Ken Aslet’ – distinguished by felted silvery leaves and brilliant yellow flowers – is usually sold as this species (but probably belongs under Oxalis melanosticta). Also invaluable for winter bloom are lilac-flowered, fuzzy-leaved Oxalis hirta; candy-striped Oxalis versicolor (with white, carmine-edged petals); and numerous other Cape Oxalis. All flourish in a porous potting mix kept reasonably moist in winter and dry and relatively cool in summer.

Look for these and other winter-blooming Cape bulbs in mainstream and specialty plant catalogs, as well as in local greenhouses and grocery stores. A touch of South Africa can do wonders for a dreary winter’s day.

Holiday House Plant Hangover

The holiday razzle-dazzle is over, and it’s back to real life. Nothing symbolizes the banality of January more than the Holiday Houseplant Hangover, a unique form of misery that comes from dealing with the remains of once-gorgeous amaryllis, paperwhites, Christmas cactus, and poinsettias.

Some people cure the condition with tough love, depositing the declining plants on the compost pile or in the trash, and speeding to the nearest garden center for a few fresh-faced African violets or moth orchids. Then there are those die-hards who consider it a moral failing to discard a desiccated poinsettia. They devote themselves to the fading botanical belles, taking all the pains necessary to ensure eventual rebloom.

If you are one of those two types, you already know what to do, but what if you are a fence-sitter, unable to decide if your flowerless Christmas cactus is worth lifting a weakened, post-holiday finger? The cure for your case of Holiday Houseplant Hangover depends on the type of plant and your level of commitment. Before making your decision, weigh the options below.

Paperwhites

For most people, paperwhites (Narcissus tazetta varieties) are one-shot wonders. Many varieties, like the popular ‘Ziva’, are marginally hardy (USDA Hardiness Zones 8-10) outdoors in cold winter climates, though others are considerably hardier. If you live where they won’t survive, make a guilt-free trip to the compost bin.

Those basking in environs with warmer winters can plant the paperwhite bulbs outside in the ground in spring, where they may prosper in years to come. Store them in a cool, dark place after they bloom indoors before planting then 6-inches down in the cool spring soil. Forced bulbs often take a year off before reblooming.

Poinsettias

Is a poinsettia plant (Euphorbia pulcherrima) that you bought at a big-box store for $4.50 really worth many months of aftercare? If you think it is, it’s possible to keep it going. After the blooms fade, move it to a uniformly brightly lit spot, where the temperature hovers between 60 and 70 degrees Fahrenheit. Water thoroughly when the top of the soil feels dry, but don’t let water pool in the plant saucer. Apply a soluble houseplant fertilizer once a month, according to manufacturers’ directions.

Lop the old flowering stems back to about 4-6 inches in early March, making sure a few leaves remain on each stem. This is also a good time to repot, if necessary, using a high-quality potting soil mixture, like Fafard® Ultra Potting Mix.

In spring, when night temperatures consistently hover above 50 degrees Fahrenheit, place the plant in a lightly shaded outdoor location. Prune the shoots back again in mid to late July to encourage branching. Around Labor Day, bring the poinsettia inside and place in a sunny spot.

To get it to bloom, keep the plant in total darkness from 5:00 pm to 8:00 am every day, before returning it to its lighted position. You can either cover it with an opaque black cloth or place it in a dark room. Reduce water and fertilizer applications during this time. Continue this routine from October 1st to December 1st, by which time you should see the festive colored bracts we all associate with the holidays. The plant should be ready for its second turn in the spotlight.

Amaryllis

Amaryllis (Hippeastrum hybrids) often flourish in the long-term, though they may produce fewer blooms the second year, without good care. Clip off dead flowers, but don’t remove stalks until they begin to turn yellow. As the bulb sprouts new leaves, water when the top of the soil feels dry and fertilize every two weeks.

Like poinsettias, amaryllis appreciates a summer vacation outdoors but are happiest in a sunny location. Bring them inside at Labor Day. If well cared for and allowed to remain evergreen, the plant will eventually rebloom in its own time. To control the timing, stop watering and let the plant languish in the dark for eight to 12 weeks, returning it to a brightly lit place when new growth appears. Resume watering and fertilizing.

Amaryllis like to be cozy in their pots, so only repot every three years, making sure that the new container is no more than two inches wider than the bulb’s diameter. Detach and pot any offshoot bulbs that have sprouted. They will grow on and may eventually flower. (Click here to learn more about growing and caring for amaryllis year after year.)

Holiday Cactus

Post-bloom Christmas cactus — Post-bloom, keep your cactus in a bright, sunny space for the remainder of the fall and winter.

Thanksgiving and Christmas cacti (Schlumbergera truncata and Schlumbergera bridgesii, respectively) often enjoy a healthy afterlife. Thankfully, the plants are relatively unfussy. Post-bloom, keep your cactus in a bright, sunny space for the remainder of the fall and winter.
Like poinsettia, holiday cactus can vacation outdoors in semi-shaded comfort. Pinching back stems in June will result in more flowers later on. When it comes to flowering, these holiday favorites share poinsettia’s proclivity for long, dark spells. To control bloom time, the plants should spend six weeks on a regimen of fourteen hours a day in continuous darkness and ten hours of bright light, at an ideal temperature of about 68 degrees Fahrenheit.

Water holiday cactus when the soil surface is dry, except in the fall, after the plant has set buds, at which time the soil should be kept uniformly moist. Fertilize monthly from late winter through summer’s end with soluble fertilizer diluted to half strength. Every few years, repot in spring, using a mixture of six parts high-quality potting mix, like Fafard® Professional Potting Mix.

Whatever option you choose to cure Holiday Houseplant Hangover, don’t add guilt to the mix. Life is too short and houseplants too plentiful to mourn a poinsettia.

Growing Miniature African Violets

Miniature African violet (Saintpaulia ionantha hybrids), look and act very much like their larger violet siblings. The big difference is the small size. Minis feature a basal leaf rosette that is only 3 to 6 inches in diameter, making them perfect for limited growing space, terrariums and other special situations.

African Violet History

African violets are not true violets, but members of the Gesneriaceae family. Their wild ancestors were first collected in 1892 from forests in what is now Tanzania by Baron Walter St. Paul, a German colonial official, and amateur botanist. St. Paul sent the specimens to his father in Germany, who passed them on to Hermann Wendland, Director of the Royal Botanical Garden, who first described them. Eventually, the new genus was christened Saintpaulia, after Baron St. Paul. The species name, “ionantha” means “violet-like,” in honor of the purple flowers.

The violets arrived in New York in 1894. They caught on with plant lovers and by 1946, they were so popular that a group of enthusiasts formed the African Violet Society of America (AVSA). The society, which is also the registration authority for new violet varieties, now describes itself as “the largest society devoted to a single indoor plant in the world.”

Red African Violets — Petal edges may be exuberantly ruffled.

African Violet Sizes

As the vogue for African violets grew, breeders created new varieties, expanding the range of flower and leaf forms and colors, as well as plant sizes. Miniatures are one of a handful of recognized size categories. The others are micro-miniatures (less than 3 inches in diameter), semi-miniatures (6 to 8 inches), standard (8 to 16 inches) and large (over 16 inches). Minis, micro-minis, and semi-minis are genetically predisposed to small size, but may occasionally grow larger than the dimensions that define their categories.

African Violet Flowers and Leaves

Like their larger relatives, minis may have single, semi-double or double flowers. Traditional single flowered varieties feature five petals, with the two on top slightly smaller than the bottom three. Petal size is more uniform on varieties with single, star-shaped flowers. Petal edges can be flat, slightly wavy or exuberantly ruffled. Color possibilities include shades of white, pale green, pink, red, yellow, purple and blue-purple, as well as combinations of those colors.

Miniature African violet leaves are sometimes as interesting as the flowers, with variations in shape, size, texture, leaf edges and color. Some varieties bear bi-colored foliage with contrasting variegation in shades of green, tan or cream.

Pink African violets — Semi-double varieties may feature bi-colored petals.

Miniature African Violet Care

Beautiful minis need loving care. This starts with a free-draining, soilless potting medium like Fafard African Violet Potting Mix. Good drainage is essential to violet health because too much moisture causes deadly crown rot. Once potted up, minis should be watered whenever the surface of the soil feels dry to the touch. Feed the plants each time you water with a diluted solution of balanced fertilizer (for example 20-20-20), following manufacturers’ directions, or using one 1/8 teaspoon fertilizer per gallon of water. If you water from the top, avoid the leaves, as water droplets cause unsightly leaf spotting. Water from the bottom by filling the saucer and allowing the plant to stand for an hour before emptying out the remaining water.

Indoors, minis need bright, indirect light from east or west-facing windows. South-facing windows may also provide good light in the winter but need to be covered with sheer curtains in summer to prevent leaf burn. Promote balanced growth by turning the plants about 90 degrees each time they are watered. Plants may also vacation outdoors during the growing season, as long as they are positioned in light shade.

Grooming African Violets

Groom miniature African violets by removing dead or dying leaves. To promote flowering and maintain the plants at the optimum size, do not allow them to produce more than five horizontal rows of leaves. Rejuvenate overgrown specimens by removing the lowest row(s) of leaves and repot, if necessary, using fresh potting mix. Minis and other African violets flower best when they are somewhat pot-bound.

For more information on minis and other African violets, contact the African Violet Society of America, 2375 North Street, Beaumont, TX 77702-1722, (409) 839-4725.

Indoor Bloomers for Midwinter Cheer

Streptocarpus 'Party Pinafore' — Streptocarpus ‘Party Pinafore’

Most of us in the Frozen North could really use a hit of spring about now. How about flowers, for instance? Or better yet, how about a lush plant in full bloom, providing a colorful (and therapeutic) dose of midwinter cheer?
That won’t be happening in most of our gardens for a few weeks yet (although here in southern New England the early witch-hazels often open their spidery blooms before February is out). On the other hand, any number of plants will provide a bevy of winter blooms in a sun room or kitchen or any suitable indoor space, given a modest investment of care. Furthermore, some of them double their display with equally showy foliage.

Purple-leaved Oxalis

One sure sign of spring’s approach is the mass arrival of purple-leaved oxalis (Oxalis triangularis) in supermarkets and department stores, in anticipation of St. Patrick’s Day. This handsome and easy-to-grow perennial is much more than a one-holiday wonder, however. Although the deep-maroon, three-lobed, shamrock-like leaves give it obvious St. Patty’s Day caché, they are perhaps even more appealing in winter, especially when punctuated with the pale pink, funnel-shaped flowers that this South American native produces year-round. Plants can also be purchased as “bulbs”, which are actually scaly, caterpillar-like underground stems (rhizomes) that should be planted horizontally an inch or two below the soil surface in Fafard® Professional Potting Mix. Full to partial sun, almost any potting mix, and anything but total neglect will keep this tough perennial happy. It is also remarkably cold-hardy, functioning well as a foliage accent in mixed borders and other perennial plantings from Washington DC into the South.

Calatheas

Calatheas, like purple-leaved oxalis, are typically known and grown for their showy foliage. Yet, a few surprise us with blossoms that stand clear of the foliage in an arresting and anything-but-drab display – rather than cowering blandly near the bases of the leaves. Among the best of these showy-flowered peacock plants are a series of hybrids developed in Indonesia in the early 2000s. And none is better than the cultivar ‘Holiday’, whose striking blooms – with rose-pink, pale-eyed petals tipped with olive-green – open sporadically throughout the year. When not in flower, ‘Holiday’ provides ample ornament with its broadly oval, bright green leaves marked by purple-black chevrons and silvery, purple-edged margins. Other ever-blooming calathea hybrids include ‘Constellation’, ‘Jungle Cat’, ‘Maria’, and ‘Royal Standard.’ (Their flowery parent, Calathea loeseneri, also makes a wonderful subject for a shady indoor nook.) All calatheas prosper in full to partial shade, warm humid conditions (although they’ll tolerate less), and a coarse humus-rich potting medium. Fafard African Violet Potting Mix is a good fit. Repot and divide plants yearly or once every two years.

Orchids

Terrestrial to semi-terrestrial orchids of many types bloom beautifully in the winter months. Most notably are Cymbidium, Paphiopedilum, and Phaius species, grexes, and cultivars. All provide bright, long-lasting floral color and thrive in Fafard’s Premium Orchid Mix, which offers a perfect blend of fir bark, chopped coir and perlite.

Spiral Ginger

For sheer nonstop flower power and ease of care, few plants can match spiral ginger (Chamaecostus cuspidatus, formerly Costus cuspidatus). The golden-orange, ruffle-edged, blooms look almost orchid-like and appear year-round on cane-like, 2-foot-tall stems clothed with glossy, dark-green, broadly lance-shaped leaves. Flowering is most abundant in summer, but blooms continue to open throughout fall and winter, particularly in warm humid niches. Give it bright shade, a fertile compost-rich growing medium, such as Fafard® Organic Potting Mix, and moderate watering for maximum display. Other members of the costus tribe, like dwarf cone ginger (Costus woodsonii) and crepe ginger (Cheilocostus speciosus), thrive in similar conditions, and are also well worth seeking out.

Oxalis triangularis 'Francis' — Oxalis triangularis ‘Francis’

Streptocarpus

No discussion of winter-blooming (and ever-blooming) houseplants would be complete without mention of cape primroses. Members of the southern African genus Streptocarpus, and close relatives of African violets, these little evergreen perennials perch easily on a modest windowsill (fitting happily in a 4-inch pot), where they bloom their heads off year-round, the funnel-shaped flowers smiling from atop wiry, 4- to 8-inch stems. Hybrids abound in all manner of luscious exotic colors and patterns, with the flowers’ two rounded, ear-like upper lobes typically differing in hue from the three lower ones, and their throats often bearing dramatic contrasting streaks. Partial shade, Fafard African Violet Potting Mix, mild humid summers, and coolish somewhat drier winters will result in nearly constant blooms, and loads of midwinter cheer.

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