Houseplants: Share the wealth

I have three houseplants I’d like to share with a friend: a heartleaf philodendron, ZZ plant, and an African violet. What’s the easiest way to divide them?

Many houseplants can be shared. Some root from leaf or stem cuttings, others can be removed from the pot and divided at the rootball. All three of the plants named here are easily propagated.

Heartleaf philodendron: These are easy to root from stem cuttings. You can try to simply cut the tip of a stem with several leaves from the parent plant just below a node (where a leaf attaches to the stem). Remove the bottom leaves, and place the stem in a jar of water. Change the water frequently, and with luck, the stem will begin to grow roots at the node. When there are enough roots to support the plant’s growth, transfer it to a pot filled with sterile potting mix.

A better method, though, is to dip the freshly cut stem in rooting powder (usually sold in garden centers) and stick the stem into seed-starting mix. Water the mix gently, or spray with a mister, and cover the pot and cutting with plastic. Mist it daily. New growth should appear in a few weeks, and the new philodendron can be transplanted into regular potting mix.

ZZ plant: Zamioculcas zamiifolia – ZZ for short – grows from rhizomes (fleshy, sometimes bulbous underground stems), so it’s a simple task to share parts of an overgrown plant. Simply lift the plant out of the pot and separate the rhizomes by pulling them apart gently Replant the rhizomes into clean pots with new potting mix, water, and maintain as usual.

You can also propagate ZZ from plant cuttings. Plant the cuttings in potting mix that drains well, water lightly, and place the cuttings in a warm, brightly lit area. This is a slow-growing plant, so it may take weeks or months before the new plant shows signs of rooting. Whatever you do, don’t overwater. ZZ is usually happier on the dry side.

(For more information about Zamioculcas zamiifolia, check out my article How to Care for a ZZ Plant at HGTV.com.)

African violet: These sweet little plants are easily shared by rooting petiole (leaf stem) cuttings. Cut a healthy leaf with its stem from the parent plant, trim the stem to about and inch or inch-and-a-half long, and stick the end of the stem into damp seed-starting mix. You may want to cover the pot with plastic to keep the cutting humid and warm. In any case, check daily to make sure the soil remains lightly moist. In a few weeks, you will see tiny plantlets emerge from the soil. At that time, you can transplant it to regular potting mix and cut away and discard the parent leaf.

This is a good technique to use when you accidentally knock a leaf off your established African violet. More plants for your friends, and for your own indoor garden!

Water worries for houseplants

Question: I use tap water to water all my houseplants, but I’ve heard that’s not always a good idea. What difference does it make?

Most people don’t think about the water they use to water houseplants —  just turn on the tap and fill the watering can. But what’s in your tap water may make a difference in how your plants grow.

Garden author Barbara Pleasant talks about water problems in her book, The Complete Houseplant Survival Manual. She says most plants prefer “soft” water, which contains low amounts of calcium and magnesium salts, over “hard” water, which contains high amounts of these elements. Water softeners remove the mineral salts through filtration or magnetization, but the water still contains high levels of salt, she says. This could lead to problems when it is used to water plants.

‘Cactus’ blooms for the holidays

My Christmas cactus always blooms early, sometimes before Thanksgiving. Is this normal? How can I keep it blooming longer?

It’s possible the plant you call Christmas cactus is actually a Thanksgiving cactus – yes, there are two slightly different varieties. Look at the stem segments: if the margins have two to four sharp serrations along each edge, the plant is Schlumbergera truncata, the botanical name for Thanksgiving cactus, which blooms slightly earlier. If the segments are more rounded, the plant is S. bridgesii, Christmas cactus. That’s the one more likely to bloom in December or later.

Both are photoperiodic plants – they respond to the change in proportions of light and dark, and begin to form buds as days shorten and nights begin to get longer. They also thrive in the same conditions: bright light and a moderate amount of water, and a dose of balanced fertilizer every now and then. (In her book The Complete Houseplant Survival Manual, houseplant expert Barbara Pleasant suggests once-a-month feeding in winter.)

Christmas and Thanksgiving cacti are generally easy-care plants. They benefit from being outdoors during the summer, but bring them inside when nighttime temperatures drop to 40 to 50 degrees. Place them out of bright sunlight, then when buds begin to form, bring the plant into the bright light.

One other thing to know: when the plant is full of buds, it sometimes seems to resent being moved, so once it’s placed in a good spot for winter, try to avoid moving it. “Once plants begin blooming, they may drop their blossoms if exposed to any kind of stress,” Barbara Pleasant writes. A stable environment should keep those blooms going longer.

They are easy to share. Schlumbergera propagates easily from stem cuttings, and a plant can live for several years, even a decade or two.

Norfolk Island pine for Christmas

QUESTION: I live in a small apartment and don’t have room for a big Christmas tree, so I’m thinking of hanging ornaments and small lights on a Norfolk Island pine in a pot that is sold as a houseplant. How should I care for the plant when Christmas is over?

If you treat it carefully, a Norfolk Island pine is a fine small alternative to a big tree – you may even see them sold in some garden centers already bedecked with a few baubles. If you’re decorating your own, use lightweight ornaments – heavier ornaments could break the limbs – and use lights sparingly. A small string of LED bulbs should lend a festive glow. Remove everything shortly after Christmas is over.

As a houseplant, place the tree it in a cool room in a spot that gets bright, indirect light – a south- or west-facing window is good – and give it a quarter-turn once a week to encourage it to grow straight up.

The biggest threats to Norfolk Island pine are dry soil and dry air. Keep the soil consistently moist, but don’t let the pot sit in water. Increase humidity in its environment as much as possible. A daily misting could go a long way toward keeping the plant healthy. If the air remains too dry, the Norfolk Island pine responds by dropping its needles, and once they’re gone, they don’t grow back.

Houseplant specialists suggest using a balanced fertilizer once a month in summer. And be on the lookout for pests, because spider mites and mealybugs are drawn to this plant. A cautionary note about placing it outdoors when the weather warms up: it’s a very tender plant, and will be damaged if the temperature falls below 40 degrees.

With care, a Norfolk Island pine can last for many years. They are native to the South Pacific (Norfolk Island is a small speck of land between Australia and New Zealand), and in their home environment they grow very large. Indoors as a houseplant, the tree usually grows, over time, to about 6 feet.

Low-maintenance houseplants for a novice gardener

QUESTION: I’m looking for a low-maintenance houseplant to give to a friend who says she kills everything she tries to grow. What’s the best choice for a person like that?

All houseplants need some care, but there are a few that can survive a fair amount of neglect. Here are three:

Snake plant

Peace lily

Spider plant

Snake plant (Sanseveria trifasciata): If you have ever had one of these, it can seem like it lives for years with no care whatsoever. With only a little care, it grows tall, sturdy, sword-shaped dark green leaves with yellow or white edges. It will survive in dim light, but in my experience a little filtered light keeps it growing happily. Water it enough to keep the soil slightly moist, but take comfort in knowing that if you forget to water it for a time, it’ll be okay. I’ve read that plants that grow to old age sometimes produce clusters of white flowers in winter, but I’ve never seen that happen.

Peace lily (Spathiphyllum): There’s a reason you see these things in offices and shopping malls everywhere. They are easy to grow, they don’t need a lot of sun to thrive, and they are not fussy about humidity. Plus, when they’re treated with a modicum of attention, they sometimes surprise you with their elegant, spoon-shaped white flowers. The soil should be kept slightly moist, but if they do dry out too much, they’ll let you know by wilting so dramatically that you run to the faucet to get them a quick drink. They spring back in a few hours.

Spider plant (Chlorophytum comosum): This one looks more delicate than many other houseplants, but it’s tougher than you think, and “an excellent houseplant for beginners,” says houseplant specialist Barbara Pleasant. The mass of strappy leaves grows from a central crown, and the plan soon begins producing small, white flowers on the tips of stems that produce more plantlets. It’s happy in a room with moderate to bright light, appreciates lightly moist soil in spring and summer but can tolerate dry-soil conditions for a time, especially in winter.

Keep your Valentine flowers fresh

Happy Valentine’s Day! Did someone give you flowers?

Whether they’re cut flowers or potted flowering plants, from a florist or from the nearest grocery store, here are tips from a variety of sources and experts on keeping the blooms fresh so you can enjoy them as long as possible.

Cut flowers: If someone hands you a bouquet of cut flowers in a cellophane wrapper, try to get them back in water as quickly as you can. Flowers that have been out of water for any length of time have reduced ability to conduct water into the stems, so hold the stems underwater and cut a bit from the bottom and leave them in water until you can arrange them in a vase.

Use a clean vase and cool water with a floral preservative added. When you cut the stems to the desired length, remove the lower leaves. Check the water level of any arrangement of cut flowers every day, and change the water frequently. Keep the flowers away from heat sources and out of cold drafts.

Miniature roses: If you want your miniature rose to keep blooming, place the pot where it will get a lot of sunlight. Water the plant thoroughly when the soil feels dry, and groom the plant regularly to remove dead flowers and foliage. Fertilize in spring and summer. Miniature roses can be planted outdoors when the weather warms.

Florist azalea: Bloom time will be longer if you keep the azaleas cool at night, though they also do best indoors when they receive good sunlight. Keep the soil moist. If it makes it until spring in good condition, plant it a part-shade spot outdoors.

Cyclamen: These plants also require sun during the day and cool temperatures at night to develop flower buds. They will quickly droop if they are allowed to get too dry. Most houseplant lovers enjoy these for a few weeks or a couple of months while they are in bloom, and discard them when their time is up.

And when the subject is roses, I can’t do better than to give a shout-out to fellow garden blogger Chris VanCleave at Redneck Rosarian. If someone has ceremoniously presented a beautiful bouquet cradled in a sturdy box or wrapped in cellophane, the blooms require (and deserve!) special care. Here’s a link to his excellent advice on preserving your Valentine’s Day roses.

What’s blooming indoors? African violets

My African violets have flowers for just a few weeks, then go for months without blooming at all. How can I get them to bloom longer?

You might think African violets are finicky houseplants, but they’re quite easy to grow. And when they bloom in winter, their flowers can bring cheer to an otherwise gloomy day.

African violet expert Julie Mavity-Hudson of the Nashville African Violet Club passes along these tips: African violets thrive in bright, indirect light and average room temperatures. The soil should be slightly moist, but not soggy (“The thing that kills more African violets than anything is overwatering,” she says).

A plant that otherwise looks robust may not bloom because it’s not getting enough light. Move it to a south- or west-facing window in winter, where the light is brighter. Watch for too much sun, though; direct sun will burn the leaves of African violets. They also do well under plant lights.

These plants also bloom better when they are slightly root-bound, so don’t rush to re-pot. They may also benefit from a light feeding of a bloom-boosting plant food every few weeks. With the right conditions, they may bloom nearly non-stop.

 

 

Mealybugs make a meal of houseplants

One of my jade plants has some sort of white fluff on the stems. Is this normal?

Jade plant is one of many houseplants that can be affected by mealybugs.

White fluff is not normal. Your jade plant is no doubt hosting an infestation of mealybugs, tiny sap-sucking insects that will damage the plants if they are left to multiply. They appear as small, cottony growths on the stems and leaves of jade plants and many other houseplants. They do their damage by inserting their piercing mouthparts into the plant’s tissue and extracting the juices.

Mealybugs thrive in a warm, dry environment – such as inside a home in winter. Female mealybugs don’t fly, but once established on a plant, they can find their way to nearby houseplants so it’s good to get rid of them as quickly as you can – not always an easy task, because that fluff is rather waxy and resistant to pesticides.

The best way to begin to eradicate the insects is to remove them by hand. Dip a cotton swab in rubbing alcohol and wipe them off. You may have to do this two or three times until all the unseen eggs that may have been deposited have hatched. If the infestation is heavier, follow up with a spray of insecticidal soap.

Always be watchful for insects to reappear, and try to get rid of them quickly. In addition to jade plants, mealybugs may find their way onto African violets, ferns, pothos, Norfolk Island pine, schefflera, diffenbachia, pothos, philodendron and many other popular houseplants.

Mealybugs are a common problem, and information is readily available. The North Carolina State University Cooperative Extension provides information here.

Special care for holiday cactus

Our Christmas Cactus usually blooms around Thanksgiving. Sometimes the buds drop off before they’re open. Can you tell me what’s wrong? What kind of care do they need?

Thanksgiving cactus

It’s common to call all of those exotic looking winter-blooming houseplants Christmas cactus, but there is more than one type. (Schlumbergera bridgesii) is the botanical name for Christmas cactus, and it usually does flower around Christmas. But there is also S. truncata, or Thanksgiving cactus, which normally blooms about a month earlier.

In general, any of those “holiday” cacti need bright light and a moderate amount of water. Barbara Pleasant, in her book The Complete Houseplant Survival Manual, suggests letting the soil dry out a little between waterings, and providing a dose of a balanced fertilizer about once a month in winter.

Christmas cacti are photoperiodic plants – that is, they respond to the change in proportions of light and dark, and begin to form buds at the onset of longer nights and shorter days in fall. Blooms open a few weeks later.

They can also be finicky about a change in conditions once they begin to bud – if you move them around, for instance. “Once plants begin blooming, they may drop their blossoms if exposed to any kind of stress,” says Barbara Pleasant in her book about houseplants.

More information and care tips from the Clemson University Cooperative Extension Home & Garden Information Center: the Schlumbergera is native to Brazil, and they grow as epiphytes in tree branches in shady rain forests. They enjoy being outdoors in summer, but bring them indoors when nighttime temperatures get down to 40 to 50 degrees – and certainly before frost. Place them in a cool, dark room, and bring them out into bright light when buds begin to develop.

Here’s how to tell the difference between Thanksgiving and Christmas cactus: Look at the stem segments. Thanksgiving cactus each have 2 to 4 sharp serrations along the margins. The margins of Christmas cactus are more rounded. One other distinguishing factor: When the flowers open, look at the pollen-bearing anthers. The anthers of Thanksgiving cactus are yellow; those on Christmas cactus are purplish-brown, according to the plant experts.

 

For houseplants, go easy on the water

Question: I’m told I’ve been over-watering our houseplants, yet we have sprigs of plants rooting in jars in nothing but water. How can a plant be over-watered when it can also be rooted and flourish in water? And how do you know when you’re watering too much?

Snake plant – Sansevieria trifasciata

Houseplant experts agree that over-watering can have a detrimental effect on houseplants. Soil that stays too wet causes the plant’s roots to rot, and invites fungi that thrive in moist conditions. That’s why it’s important to grow houseplants in pots with adequate drainage, and to allow the soil of most plants to dry between waterings.Different houseplants also have different water requirements, and many need less water in winter when they are growing more slowly. Before you add water, poke a finger into the soil, and only water the plant if it feels dry. Or push a wooden chopstick into the soil, and if it’s not damp when you pull it out, water the plant. It is better for a plant to have too little water than too much, but you also want to make sure it doesn’t wilt.

As for plants rooting in water: many fleshy plants will quickly develop roots in plain water and can later be planted in soil. Ideally, as the roots develop, the water is kept clean by being changed frequently. But if they are kept in water long enough, even those plants that seem to thrive for awhile will eventually lose vigor and may rot, too.