Category Archives: houseplants

Stunning Streptocarpus

flowerIf you are looking for the perfect houseplant, try a streptocarpus. This beautiful flowering plant is a cousin of the African violet but with more flair. These are easy to find now in the winter at local garden centers that sell houseplants.houseplant

Native to Africa, streptocarpus is commonly called a Cape primrose. There are more than 135 species, and the size varies. The plants you see in the garden centers will have long, strap-like leaves with tubular flowers high above the plant. There are some though with only a single leaf that can range from a few inches to a few feet in length.

Grow these plants like you would grow an African violet. They need strong indirect sunlight by the window or fluorescent tubes. They grow best with day temperatures of 65 to 80 degrees and night temperatures between 65 and 68 degrees. They do not like heat so if you put them outdoors in the summer with your other houseplants, they may perish.streptocarpus

The soil should be evenly moist, but not wet. Let the soil begin to dry out just a little bit between waterings. Do not let water get on the leaves. There is specially formulated African violet soil which works well for streptocarpus plants. They need to be fertilized with a diluted balanced fertilizer. A balanced fertilizer has the same proportion of nitrogen, phosphorus, and potassium, the three numbers below the name of the fertilizer. To prevent a build up of fertilizer salts, periodically leach the plant by letting water run through the soil and out the drainage holes.

A streptocarpus is a type of a gesneriad, member of the Gesneriaceae family. These include the African violet, espiscia, columnea, sinningia, and aeschynanthus to name a few. If you really enjoy growing streptocarpus, try your hand at growing other gesneriads and consider joining the local National Capital Area Chapter of the Gesneriad Society. 

cape primrose

Versatile Kalanchoe Houseplants

Kalanchoe plants (Kalanchoe blossfeldiana) or florist’s kalanchoe are popular holiday gift plants. These blooming succulents are relatively small, no bigger than a foot tall. You may see smaller versions, about 6 inches high, that are perfect for offices.

Kalanchoe plants have dark green, thick succulent leaves with scalloped edges. Plants can have orange, red, pink, or white blossoms. Because they are succulents, water them sparingly and provide as much light as possible.  Fortunately, they tolerate low humidity, which is common in homes in the winter. Make sure they have been planted in a porous, well-draining potting mix in containers with drainage holes.

The flowers last for a long time. When they are past their prime, simply snip off the flower stalks and grow the plant for its foliage. You can keep the plant as a foliage houseplant in the home. When summer comes, you can either leave the plant as is in the house or take it outside on the patio after the last frost date. If you move it outside, put it in the shade first so the foliage does not get sunscald. Later in the summer, give it a well-balanced fertilizer.

It is possible to make kalanchoe plants re-bloom. Like poinsettias and holiday cactus plants, kalanchoe plants need short days and long nights to trigger flower bud formation. In nature, this would occur naturally as the days get shorter and the nights get longer in the fall. However, since you must bring these back in the house before it gets too cold, you have to mimic the transition by putting the plant in a place that has an extended period of darkness every night.

In the fall, put the plant in a room where lights are not turned on (i.e. gets dark naturally) or in a dark closet in the late afternoon for 14 to 16 hours every day. Water less often and do not fertilize. After six weeks, put the plant in a place where it receives light, either natural sunlight through the window or lamps. The plant should start to flower.

If you visit garden centers and plant stores now, even grocery stores, you will see plenty of blooming kalanchoe plants. Purchase an orange flowered one as a Thanksgiving centerpiece and a red flowered one as a hostess gift when you attend a holiday party in December.

Decorate a Norfolk Island Pine for Christmas

Holiday Norfolk Island PineIt’s beginning to look a lot like Christmas! Spotted these Norfolk Island pines at Home Depot today, decorated for the holidays. Shipped from Costa Farms in Florida, these 9-inch containers are relatively cheap considering that the plant will last for years. Add a few more lightweight ornaments, red ribbons, and miniature lights and you have the perfect “Christmas tree” for those who do not want to lug in a large cut tree or prop up an artificial tree. The added benefit of course is that the Norfolk Island pine becomes a houseplant after the holidays.

Based in Florida, Costa Farms is the largest grower of Norfolk Island pines in the United States. According to their website, Norfolk Island pines (Araucaria heterophylla) really do originate from Norfolk Island (the tiny island is between Australia and New Zealand). British explorer Captain James Cook discovered the plant in 1774. In their natural habitat they can reach up to 200 feet (image below).

Instead of trekking out to this tiny island, Costa Farms gathers seed from trees in Hawaii. They sow and grow them in Florida, trimming them at an early age to maintain a reasonable size. By the time the plants arrive at Home Depot, they are several years old but have been pruned repeatedly. Norfolk Island Pine

When you purchase a Norfolk Island pine, give it as much light as possible. It is best to put the plant on casters so it can be rotated to prevent lopsided growth. The plant can live for a long time and get as high as 9 feet.

Fortunately, they prefer to be pot bound so you do not have to re-pot frequently. Make sure the potting mix is porous. They prefer a well-drained mix. Water the plant so the water runs out the drainage holes. Water sparingly in the winter and a little more in the summer. Apply a diluted liquid fertilizer in the summer. Unlike many tropical houseplants, this one tolerates the low humidity that is common in homes in the winter. It does not have to be pruned or trimmed unless of course it is to remove a dead or diseased branch.

In 12 months, decorate again.

Happy St. Patrick’s Day! Enjoy Your Shamrock Plants

Happy St. Patrick’s Day! Although the shamrock plant looks like a three-leaf clover it is actually a species of Oxalis. These are commonly sold as St. Patrick’s Day gift plants but they make great houseplants and garden plants.

The plants can have either green or burgundy foliage. The small flowers rise high above the leaves with five white or pink to white petals. Most people grow them as houseplants but they can be grown outdoors in the summer here in Virginia. Because they are small, it is best to grow them in containers (off the ground level) for better viewing. These are great to plant at the base of a large container that has other flowers to hide bare stalks. Or combine a burgundy foliage shamrock with a green plant like lemon verbena in a container for contrast (just eat the lemon verbena, not the shamrock).

Shamrock plants grow from rhizomes called pips which can rot if overwatered so it is best to let the soil dry out a little between watering. Eventually the plant will go through a dormant period and produce more pips that can be dug up for more plants in the fall.

In the house, the plant is best grown in indirect light with cool temperatures. Usually it is only after you purchase the plant that you learn of its charm. The leaves move up and down every day. In the daytime, at maximum light, the leaves are horizontal or open. By nightfall, when light levels are reduced, the leaves bend down almost as if the plant is wilting. Don’t worry, this is normal and does not mean that you have to water.

Shamrocks are beautiful houseplants but there is one caveat: they do not combine well with pets. Oxalis contains a high level of oxalic acid, which can be poisonous.

Celebrate Valentine’s Day with a Heart-Shaped Hoya Plant

If you were lucky enough to receive a heart-shaped hoya plant, also known as a sweetheart plant or Valentine’s hoya, here is how to take care of this cute little plant.

This heart-shaped leaf is what it is, a leaf from a vine plant called Hoya kerrii. Because it is a rooted leaf and not a rooted stem cutting, it will not grow into a vining plant, it will simply exist as is. There is no growing point to develop a vine. However, if you take care of it, it will last quite a while. Provide a warm room, bright indirect light, and don’t overwater the plant. This is a succulent that needs little water and well-draining soil. Make sure the container has drainage holes.  Since you are not encouraging growth, just survival, you only need to fertilize once a year during the summer.  These plants will stay small, they won’t grow or change, which makes them perfect desktop plants.

In its natural life, Hoya kerrii is a vine with heart shaped leaves. Like other hoyas, these plants make great hanging basket plants. They have fascinating blooms, usually scented. Interestingly, we know about this plant because an Irish medical doctor named Arthur Francis George Kerr worked in southeast Asia in the early 20th century. He is known for his botanical studies of the flora of Thailand. He collected Hoya kerrii in Chiang Mai, which is in northern Thailand, and sent it to Kew Gardens in England where it flowered in August 1911. I am sure he had no idea that over one hundred years later, a single leaf cutting of this plant has become a popular Valentine’s Day gift.

Multiply Your Holiday Cactus Through Cuttings

stem cuttings twisted off holiday cactus plant

Another great winter activity, propagating your holiday cactus. By now it should be finished blooming which is a good time to take cuttings and make many more plants to give away as gifts.

Line up a few clean, small plastic containers such as yogurt containers, fruit cup containers, or plastic cups and puncture the bottoms to allow for drainage. Fill with packaged seed starting mix and water each cup so water runs through the drainage holes.

To take the cutting, simply twist off a piece of stem about three to four segments long. The stems are made up of joined rectangular segments. Each segment is called a cladode. The length should be long enough to insert into soil and stand up. You want to twist so you have the end of a segment or cladode, not mid-way into a segment. Insert into the container, water again, and tamp to ensure the stem is standing upright. You can insert several per container or just one per container.

Place on a tray, in a well-lit place, out of direct sun. The room should be warm, “room temperature,” not a cold, drafty basement.  It is not necessary to place the container in a plastic bag or to fertilize.

stem cuttings planted

Some people insert the cutting directly into the soil while others wait a day or two for the cut part to form a callus. This is done to prevent rotting. I have never had a problem with rotting so I simply insert the cutting into the wet soil.

I do not use a rooting hormone because the plant roots easily. A holiday cactus, also called a Christmas cactus or a Thanksgiving cactus, is an epiphytic plant that grows on trees in Brazil’s coastal mountains. In their natural habitat, they have aerial roots, which is an indication that the cuttings will root easily without added hormones.

For the first few weeks, I water the containers often enough so the soil is moist but not waterlogged.  Because the containers are very small, the soil will dry out faster than a full grown plant in a large container. After a few weeks, I check to see if roots have formed by gently pulling to see if there is resistance. Also, if the plant is still turgid, there is a good chance it has survived the cut and is still trying to form roots. If the plant is obviously wilted or rotted, I throw away the entire plant and container into the trash. This is one advantage to having one cutting per container; if it does not work, you only lose the one cutting and container, not many cuttings in one container.

roots formed on cuttings in 17 days

Eventually, the cuttings will form enough roots so you can transplant to a larger container with potting soil. You can either continue to grow this indoors or put outdoors in the summer and then bring back in the fall. For the cost of seed starting mix, cuttings are an inexpensive gift for friends and family. Makes a great teacher’s gift too!

A Great Houseplant: Anthurium

When I was young, we lived in Thailand and my mother (who grew up in Milwaukee) would buy plants and orchids from the market. I remember one houseplant in particular. The beautiful flowers were so waxy they looked like they had been polished with furniture polish. The red flowers would last for months. We did not know the names of the plants but we enjoyed their exotic beauty. Now that I am older, I know the waxy plants are called anthuriums. Although I associate them with tropical Asian countries, they really hail from South America tropical environments.

Anthuriums are members of the Araceae or arum family. The “flower,” the red, heart-shaped part, is a modified leaf called a spathe. The actual flowers are tiny and appear in the center vertical structure called the spadix. The “flower” lasts a long time, making them ideal for cut flower arrangements.

As a houseplant, anthuriums can grow in low light conditions. However, the more light you can provide the more likely it will bloom throughout the year. It definitely does not like moist soil. Water when the soil is dry to the touch. Anthuriums are easy, low maintenance plants, perfect for the home and office.

Usually one sees red-flowering plants at the hardware store or nursery but pink, green and white, and purple colored cultivars are available. There is even a black flower cultivar called ‘Black Love‘. My plant was less than ten dollars at the local hardware store but it was very root bound in a 4-inch pot so check your plant’s roots after you purchase it.

Anthuriums are the perfect winter houseplant: the flowers last a long time and the plant has an exotic, year round appeal. Try growing this easy houseplant or purchase one as a hostess gift when you visit family and friends this year.

Enjoying Your Holiday Cactus Year Round

holiday cactus

Thanksgiving cactus with yellow anthers and sharp leaf edges

A popular blooming holiday plant is the “holiday cactus” which is an umbrella term to include the Christmas cactus (Schlumbergera bridgesii) and the Thanksgiving cactus (S. truncata). These are not cacti at all but epiphytes from the Brazilian rainforest. In their native environment, they grow among tree branches, in the humid, shady jungles. The Thanksgiving cactus has saw-tooth serrations on the “leaves,” while the Christmas cactus has round, lobed margins. The anthers of the Thanksgiving cactus are yellow while the anthers on the Christmas cactus are purple-brown.

Both of these are grown the same way. Put them in bright indirect sunlight, keep the soil evenly moist, and provide a high humidity level. If you can keep the plant cool, like high sixties, you may be able to prolong blooms as long as 7 to 8 weeks. There is no need to fertilize in the winter while it is blooming.

christmas cactus

Christmas cactus with dark anthers and lobed, rounded leaf edges

Summer Care

In the summer, you can keep the plant indoors as a houseplant or move outdoors after danger of frost is over. Here in Virginia, I take mine out around Mother’s Day. I put mine in full shade first and then in a dappled shade area under a tree.  If you first put the plant in direct light outdoors the leaves will have sunscald, which is unsightly but not deadly.

buds

Buds appear at the end of each stem so the more stems, the more blossoms

In the summer, the plant is tolerant of dry soil. These plants prefer to be pot bound and usually are in small containers that drain quickly. If you are relying on rain, it may be weeks between watering for the small plant and the soil may become too dry so you will need to water it. Fertilize with an all-purpose houseplant food.

In mid-summer, pinch stems back to promote branching and to create more terminals for flowers. Also, this is a time to think about propagating the plant to give new ones to friends and families. Propagating is easy, see the steps below.

Initiate Blossoms

In the fall, bring back indoors before the first frost. To make it bloom again, in September, let the soil dry between watering and start to expose the plant to 5 to 6 weeks of short days. These are days in which the plant is receiving less than 12 hours of daylight. This means no artificial light after the 12-hour period (no lamps in the living room). Temperatures should be cool, below 55 degrees. When buds form, continue regular watering, bright indirect light, and cool temperatures.

Blooms on plants outside are induced by autumn’s short days and cool night temperatures. If you have kept the plant indoors, you may have to artificially induce blooms. Either turn off lights and keep the plant in the dark after 12 hours and reduce the house temperature or place the plant in a dark and significantly cooler room every evening until buds form.

Propagate

stem cuttings twisted off Thanksgiving cactus plant

To propagate, line up a few clean, small plastic containers such as yogurt containers, fruit cup containers, or plastic cups and puncture the bottoms to allow for drainage. Fill with packaged seed starting mix or a houseplant mix and water each cup so water runs through the drainage holes.

To take the cutting, simply twist off a piece of stem about three to four segments long. The stems are made up of joined rectangular segments. Each segment is called a cladode. The length should be long enough to insert into soil and stand up. You want to twist so you have the end of a segment or cladode, not mid-way into a segment. Insert into the container, water again, and tamp to ensure the stem is standing upright. You can insert several per container or just one per container.

Place on a tray, in a well-lit place, out of direct sun. The room should be warm, “room temperature,” not a cold, drafty basement.  It is not necessary to place the container in a plastic bag or to fertilize.

stem cuttings planted

Some people insert the cutting directly into the soil while others wait a day or two for the cut part to form a callus. This is done to prevent rotting. I have never had a problem with rotting so I simply insert the cutting into the wet soil.

A rooting hormone is not necessary; the plant roots easily. Remember these are epiphytic plants that grow on trees in Brazil’s coastal mountains. In their natural habitat, they have aerial roots, which is an indication that the cuttings will root easily without added hormones.

For the first few weeks, water the containers often enough so the soil is moist but not waterlogged.  Because the containers are very small, the soil will dry out faster than a full grown plant in a large container. After a few weeks, check to see if roots have formed by gently pulling to see if there is resistance. Also, if the plant is still turgid, there is a good chance it has survived the cut and is still trying to form roots. If the plant is obviously wilted or rotted, throw away the entire plant and container into the trash. This is one advantage to having one cutting per container. If it does not work, you only lose the one cutting and container, not many cuttings in one container.

roots formed on cuttings

Eventually, the cuttings will form enough roots so you can transplant to a larger container with potting soil. For the cost of the potting mix, cuttings are an inexpensive gift for friends and family.

close up of small white roots with seed starting medium attached

Save Your Geraniums for Next Year

Red geraniums in a large container in May

When my mother lived in Vienna, Virginia, she grew red geraniums in large containers by the front door. Every fall she would pull the plants out of the containers, knock off the excess soil, and place the plants on a shelf in the basement. There was one small window allowing very little light. The following summer, she would pot these up again outside and these plants would come back to life. She did this because her mother, who lived in Wisconsin, also saved geraniums in the fall. However, her mother had a sunny foyer so she would cut her plants back, repot them in smaller containers, and treat them as small indoor plants inside. Both methods worked well. Geraniums can take quite a bit of dryness which is what makes them ideal for overwintering.

If you are growing geraniums consider saving them for next year. Not everyone has a sunny foyer but most people in this area have a basement. For the basement method, this month, before frost, lift the plant out of the container. Shake the soil off and cut off diseased parts and the flowers. Let the plant dry for a few days in the shade so that excess moisture will evaporate. Then place the plant in a large paper bag and close with a binder clip.  Store the bag in the coolest place in the basement.

Periodically, check the plant to see if it is getting too dry or, conversely, moldy. If moldy, just cut and throw away those parts.  If too dry, soak the roots in water for a few hours and then dry and put back in the bag. Eventually, the foliage will die off but that is okay.  In the beginning of April, put the plant in a small container with drainage holes. It may look dead but water, warmth, and light should bring it back to life. Water the plant so water runs out of the drainage holes. Place the container in a room where it is warmer and lighter than the basement. This will trigger the plant to leaf out again. After the average last frost date (Mother’s Day in Virginia), put the container outside. Put it in shade first in order for it to acclimate to the increased sunlight. Gradually, move the container to a full sun location. You can either pot up the plant into a larger, ornamental container, pot up with other plants in a large container, or even plant in your garden for the summer.

If you have geraniums, now is the time to think about saving them so you can enjoy them again next summer. This method should enable you to enjoy your geraniums for many years to come.

Pink and red geraniums in the landscape in August

Tips on Taking Care of your Cyclamen Houseplant

If you received or purchased a blooming  cyclamen over the holidays, here are tips for taking care of this regal queen.  Also called florist’s cyclamen (Cyclamen persicum), this houseplant blooms during the winter with flowers raised high above the foliage, lasting for several months. Cyclamen is available in a range of sizes, from mini to large, as well as magenta, red, pink, and white flower colors. Beautiful as it is, cyclamen is not an easy plant to grow.

While it is blooming, give it bright indirect light. It prefers day temperatures of 60-70 degrees and night temperatures of 40-50 degrees. It also prefers high humidity. Usually homes in the winter have low humidity so place the plant on a tray of pebbles with a little water. However, make sure you have a saucer between the container and the pebbles. The root system is a tuber that is prone to rot.

Water when the soil feels dry, like dry in the top inch, but before it is completely dry. Do not let it sit in water and do not let it sit in the saucer of water. Likewise, when watering, aim for the side of the crown, not on the leaves, and not on the crown (central growing point). If you purchased it in the decorative foil covering, it best to remove that and put the pot (make sure it has drainage holes) on a saucer.

Feed the plant with a diluted liquid low nitrogen fertilizer to prolong the blooms, such as an African violet fertilizer.

After flowering, the leaves will turn yellow. Your first thought may be that it is dying and you need to water or fertilize but don’t do that. The plant is beginning its dormant stage. Don’t try to keep it green with more watering, let it rest during the summer. Put the plant in a cool, dark area with good air circulation. Don’t water or feed during its dormant period.

In the late summer, early fall, bring the plant back to bright indirect light and water thoroughly at first. You will see new green growth. Treat it like when you first purchased it and it should bloom again. It may not look as luscious, but the regal queen should continue to hold her court as a long lasting houseplant.