Top 10 ways to kill a houseplant

It’s easy to kill a houseplant.

No matter how green his or her thumb, every gardener has a sad tale about the orchid that expired, the pothos that went to pot, or the weeping fig that dropped every blessed leaf.

You can gnash your teeth, rend your garments and fume. Or you can get busy and figure out what went wrong.

Houseplants fail for a handful of reasons.  Here are my top ten:

Overwatering

The number one killer of houseplants is overwatering. Roots need both water and air to thrive.  Waterlogged soil chokes roots.

Most plants like to dry out between each watering.  Stick your finger in the soil. If it feels dry, water until the water runs out the bottom of the pot.  Let the water drain and dump the excess.

Water needs vary. Cacti like it dry. African violets like moist soil.  Find out what your plant needs and give it just that.

Improper drainage

Poor drainage also causes roots to rot.  So, make sure every pot has a drainage hole.

Low humidity

Our winter homes are dry, dry, dry.  When the heat comes on, humidity takes a nosedive.

Set plants that need higher humidity – like orchids – on a tray of pebbles with a bit of water.  Mist humidity-loving plants such as ferns once a week.  Or get chummy and shower with them.

Low light

Too much or too little light is tough on houseplants.  Read the tags and do some research in books or online to find out what your plants prefer.

Sun-worshipping orchids need strong light while dracaenas are happy in lower light.  Place each plant where it will get what it needs.

Drafts

Oh, how houseplants hate a burst of cold air or a blast of heat.  So keep them away from doors, fireplaces, radiators, vents, or chilly windows.

Overfertilizing

Indoor plants don’t photosynthesize at the same rate as outdoor plants, so they need less fertilizer.  In winter, fertilize at half the suggested strength or not at all.

Ignore pests

Bugs hitchhike on houseplants that summered outdoors.  Be vigilant and deal with pest problems swiftly.

Look for spider mites’ webs, sticky leaves from aphids or leaf bumps that are scale.  Contact your local Extension office for an ID or fix or contact the Ask Extension experts.

Shock

If your houseplant is happy, don’t move it.  Most plants resent a change of scenery.  Drama queens like ficus weep copious leaves with even the slightest change.

Pot-bound

Roots too small for a pot circle madly, strangling houseplants.  If you notice roots circling or peeking out of the bottom of the pot, it’s time to repot.

Choose a pot an inch or two bigger than your existing pot and repot with fresh soil in the spring.

The wrong soil

A light soilless potting mix is good for most houseplants.  Garden soil is a no-no, too heavy to drain well.

Some plants need specific blends.  Cacti like a sandy mix while orchids need a special chunky orchid potting mix.  Do your research.

Stop killing houseplants.  Avoid the dreaded top 10.  Your plants will love you for it and reward you with years of health and beauty.

 

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension. This article was previously published by Herald-Mail Media. Read more by Annette.

 

How Horticulturists Turn Quarantine Into ‘Gardentine’

While it seems that everything in our world is different today than it was two months ago, one thing hasn’t changed — nature! Maryland’s stay-at-home order has given everyone the opportunity to explore their natural surroundings and given them the itch to garden to relieve tension and do something productive.

So what do University of Maryland Extension horticulturists do to stay grounded during ‘gardentine?’ Just like you, we take pictures of our flowers, gardening projects, and all things nature and send them to each other, natch!

Stephanie got us started by wishing us a happy Earth Day!

horticultural distancing is not a thing

Stephanie and I went on a socially distant walk, participating in the City Nature Challenge iNaturalist project for the Baltimore area. Here are a few of the 53 species we identified for the project. Not too shabby!

Scroll over or click on the images to see the plant names.

One of my neighbors really upped the game by providing informational signs along the sidewalk for everyone’s enjoyment! Thanks, Kathy!

Christa started her “Sketches from the Yard” journal on the 10th day of quarantine. She says drawing, painting, and writing about her observations around the yard and garden is a creative thing she can do at home and is something that helps her relax during these strange times.

“When I look at the details of a plant and try to document it, it gets my mind off the coronavirus news for a while and helps me focus on what is still normal and beautiful around me. I have appreciated my garden harvests of fresh greens, herbs, and even a few carrots that survived our mild winter. And the new tulips I planted last fall were delightful to see in bloom! At the end of this project, I will have a record of my garden and how meaningful it was to me as a place of serenity during this quarantine time.”

She is quite the garden journalist! You can follow her on Instagram @mrscarignan.

Debbie is growing microgreens in a salad box on her balcony.

microgreens in a salad box
Half of the box is arugula and half is lettuce that has just started to germinate. Proving that you don’t need a lot of space to grow some of your own food! Photo: D. Ricigliano
salad box
This is what a salad box can look like when it’s ready for the first harvest. Yes, you can get multiple harvests from salad greens. Photo: HGIC

Miri has quite the impressive indoor garden! The ridiculous volume of houseplants keeps her sane! (Her words, not mine!) Maybe Miri will write a blog post featuring her various mini orchids and Tillandsias and include the routine she uses to keep them all so happy! (Hint hint!) She also entertains herself by secretly diagnosing plant problems on walks through the neighborhood. No photo evidence of that here!

Marian is helping her daughter plant a salad box from a distance by sharing the Home & Garden Information Center’s salad box instructions. See how you can build and plant a salad box or a salad table too!

salad table
I can see that Marian is also using a floating row cover to protect those seedlings from frost and/or marauding squirrels and chipmunks! Photo: M. Hengemihle

Jon has a huge and very productive garden every year! He always gets his garlic planted in the fall.

garlic
This spring the garlic tips have turned yellow either from the cold or the beginning of his perennial problems with white rot and bulb mites. Oh no! Photo: J. Traunfeld

Jon also grows his own seedlings every year and generously supplies the office with baby plants! Thanks, Jon!

growing transplants on a light stand
Here is Jon’s light stand setup. He’s growing downy mildew resistant ‘Prospera’ basil, many varieties of pepper, tomato, eggplant, zinnia, and tithonia. Photo: J. Traunfeld

Wanda enjoys tending her orchids indoors.

orchids indoors
She soaks them in a container of water for about 10 minutes every 2 weeks in the winter and once a week when it gets warm. Photo: W. MacLachlan

Wanda has lovely gardens outdoors too.

raised beds
Here she and her husband are revamping their raised garden beds in an attempt to exclude deer, raccoons, groundhogs, rabbits and (fingers crossed) chipmunks! When finished, these 3 raised beds will be in a closed cage. Stay tuned for a progress report! Note from Wanda: The dark piles in the 2 beds are castings from her indoor vermicomposting project. Wow! Photo: W. MacLachlan

Jean has a passion for pink and her houseplants prove it!

plants on a windowsill
Luckily, she has a south-facing window so she gets a lot of light. For the succulents, she mixes potting soil with some perlite and avoids overwatering. High sun exposure and good drainage is key to her healthy and happy houseplants! Photo: J. Burchfield

Ria – I sheltered in place for part of the last 6 weeks at the home where I grew up in Virginia. I went on several walks taking photos of things in bloom, but I needed to get my hands in the dirt! I had assured Jon in February that I was absolutely not going to create another garden to manage there. He had a good laugh when he saw the photos of my new garden! So much for my resolve, I needed to garden!

For the last 40 years, only daffodils and a perennial hibiscus have grown in the small triangle of space bordered by the split rail fencing, if you don’t count that sneaky Bermuda grass. If you look closely, you might be able to see the pomegranate that I got in Colonial Williamsburg about 5 years ago. It has never even bloomed, let alone produced fruit!

bare ground new garden
To create the new 24’ x 12’ kitchen garden, I killed the grass (mostly Bermuda grass and various other weeds), spread thick layers of newspaper over the area and covered it with soil that had been excavated to install French drains. Photo: R. Malloy
add organic matter to a garden
Then I spread ten bags (2 cu. ft. each) of media labeled for raised beds in 3 rows each about 2.5’ wide, leaving room for a path between each row. I mulched between the rows and around the perimeter of the garden with wood chips from 3 tree stumps that we ground up last summer. I made sure not to incorporate the wood chips into the soil with the plants. Photo: R. Malloy
planting a new garden
I planted a variety of herbs, sweet cherry and grape tomatoes, salad greens, and flowers to attract pollinators. Photo: R. Malloy
new garden
My husband extended the split rail border. I surrounded the garden with green plastic covered wire mesh fencing to deter the rabbits and groundhogs. I am under no illusions that it will really prevent them from getting in! At some point I will need to add a solar powered electric fence like the one I have in Maryland. Photo: R. Malloy

Please join us by taking time each day to connect in some way with nature and stay grounded during ‘gardentine’ and beyond!

By Ria Malloy, Program Coordinator, Home & Garden Information Center, University of Maryland Extension

Orchid Care: Consistency Is Key

Phalaenopsis
Creating an environment that mimics an orchid’s native habitat will ensure plentiful blooms. To thrive, each orchid needs the right spot. Check your orchid’s individual profile. Photo: Rachel Rhodes

My love affair with orchids began in college. It was the winter of 2007 while in Belize for a winter semester class “Tropical Agriculture, Conservation, and Ecosystems.” Sitting along the tranquil headwaters of the Bladen River, our guide detailed the dynamic relationship of the ecosystem that surrounded us.

In the heart of the rainforest, the delicate balance of our environment beats like a drum. As our guide described the four layers of the rainforest from the emergent layer, to the canopy layer, to the understory, and the forest floor, birds chirped and vivid blue morpho butterflies fluttered around. Our guide pointed above us to the most beautiful mesmerizing orchid I had ever seen; the black orchid.

The black orchid gently dangled off the leaning tree beside us, its greenish-yellow petals and sepals had the most beautiful purple blotches near the base. While the “lip” was shaped like the valve of a clamshell, it was deep purple to black and radiated with purple veins. I had never encountered such a fascinating flower.

After the class ended, I dove headfirst into all things orchids to absorb as much information as I could. The orchid family boasts some of the most extraordinary and diverse flowers in the plant kingdom, with around 30,000 species and 120,000 hybrids.

Generally, orchids are divided into two groups; epiphytic and terrestrial. Epiphytic orchids are usually the orchid we most frequently see (Phalaenopis and Cattleya). Epiphytic orchids use their tough roots to anchor themselves to trees. They receive nutrients from rainwater and leaf debris and they absorb moisture from the air. Terrestrial orchids grow with their roots in the ground. They are most commonly found in grasslands or boggy areas. Understanding the type of orchid you have, their growing conditions, light requirements and flowering season is integral in ensuring your success.

orchid
Glazed pottery and ceramic orchid pots come in varying hues, shapes, and sizes. Decorative pots are fun but make sure to keep an orchid in its original plastic container and place it inside the decorative pot. If you take it out of its plastic container, too much air will get to the roots and the orchid will dry out faster. Photo: Rachel Rhodes

After much trial and error, I have learned a few things. With orchids, consistency is key. A majority of our orchids such as Phalaenopsis only bloom once a year in late winter through early spring (January to March). Getting them to rebloom is the ultimate prize as a gardener. The best way to encourage flowering is make sure that you have the proper lightening, ample water, and the right amount of food.

First, getting the light right is one of the most important factors. Phalaenopsis and Paphiopedilum like morning light from an east-facing window. This provides an orchid with a few hours of direct sunlight without hurting the plant. The sun can be very damaging to the leaves of an orchid, so the right placement is key. If you do not have an east-facing window, you can make other spots work by following these principals. North facing windows simply do not provide enough light to sustain the healthy growth of an orchid. If this is your only option, you will need a grow light to give your orchid the boost of light it needs. If your orchid is in a west-facing window put up a sheer curtain to protect it from the heat of the summer sun. Furthermore, if using a south facing window a sheer curtain is advisable year round. Unlike Phalaenopsis and Paphiopedilum, Cattleya like bright light from a south or west facing window.

applying water to orchid roots
Water your orchid once a week. Make sure that you take it out of its decorative pot, leaving it in its plastic container. Run water over the roots for a few minutes avoiding the leaves. Allow the plant to air out for a while before putting it back into its decorative container. Photo: Rachel Rhodes

Just as getting the right lighting is crucial so is watering. When watering your orchids, always water in the morning. This guarantees that the moisture has time to evaporate. If you water at night, it allows water to settle in the nooks of the bark, which promotes fungal growth. Avoid watering or misting the leaves. Misting tricks the guard cells on the leaves to think that the humidity is higher than it actually is. This can cause your orchid to dry out faster. Additionally it can lead to crown rot if water settles in the nooks of the leaves. Orchids love humidity. To increase humidity you can use a humidifier set at 40-50% or use a humidity tray.

mealybugs on orchid buds
Mealybugs are a common orchid pest, especially on moth orchids (Phalaenopsis).They are little white fluffy insects that are closely related to scale insects. They love new growth and flowers. Unlike scales, mealybugs wander in search of feeding places. They damage the overall vigor of the plant, weakening it and causing the loss of leaves, buds, and flowers. Photo: Rachel Rhodes

All plants require nutrients to grow and thrive. Epiphytic orchids like Phalaenopsis live in trees where they receive nutrients from rainwater and leaf debris. Pot-grown orchids depend on feedings to produce healthy leaves and beautiful blooms. With proper feedings, a well-fertilized orchid will keep their leaves longer and will produce more flowers. When feeding, it’s best to use orchid-specific fertilizers. Orchids also thrive from “weakly weekly” feedings when blooming by diluting fertilizer to ¼ strength rather than a full dose once a month.

By Rachel J. Rhodes, Master Gardener Coordinator, Queen Anne’s County, Maryland, University of Maryland Extension. Follow the Queen Anne’s County Master Gardeners on Facebook. Visit the UME Master Gardener webpage to find Master Gardener events and services in your county/city. 

February Tips and Tasks

Houseplants by window

  • Day length is increasing and the sunlight is more intense. Houseplants will begin to show signs of new growth. It is time to start fertilizing your indoor plants.
  • Leaf yellowing and leaf drop from houseplants can be a result of low light conditions combined with overwatering. Spider mites are another possible cause.
  • Spring bulbs can still be planted if the ground is not frozen. Inspect the bulbs and plant only the solid, healthy ones as bulbs can deteriorate when stored.  They may still bloom this year but will not be as vigorous. Do not cut back the green foliage that emerges, let it die back naturally.
  • Keep garden beds covered with shredded leaves, straw, or bark mulch to minimize the risk of soil erosion and nutrient run-off.
  • The Maryland Lawn Fertilizer Law prohibits anyone from using fertilizer products to melt ice and snow on steps, sidewalks or driveways.

Find more February Tips and Tasks on the HGIC website.

Q&A: Why Is My Clivia Plant Starting to Yellow?

clivia plant
Q: Many years ago, I purchased a Kaffir Lily (Clivia miniata) at the Philadelphia Flower Show and it has special meaning to me. Recently, the bottom leaves are turning yellow. What is causing this and what should I do? Also, sometimes it does not bloom well. Is it true that they need a rest period?

Answer: It is normal for the older leaves to turn yellow and eventually shrivel as the plant ages. Prune off the affected leaves. The rest of the leaves should be green, strappy, and healthy. Yellowing of younger leaves can indicate overwatering: a more-serious symptom. The potting mixture should dry out slightly between waterings when it is actively growing and completely dry out during the rest period.

Clivias do need a dormant period to help with blooming. Starting in late fall or early winter, withhold water and fertilizer and move the plant to a cooler area where temperatures are in the 40–50° F range. Keep it there for about 6–8 weeks, then move it back to a sunny location and begin to water again. You will soon see some
new growth and a flower stalk. At this point, begin to fertilize it every two weeks with a water-soluble houseplant fertilizer at half-strength. They bloom best when pot bound. Repot your Clivia every three to five years in the spring, after the flowers fade, when necessary.

Visit the Home & Garden Information Center website for more information about houseplant care.

By Debra Ricigliano, Lead Horticulturalist, University of Maryland Extension Home and Garden Information Center. This article was published originally in the December 2019 issue of Washington Gardener magazine. Read more posts by Debra.

Have a plant or insect question? University of Maryland Extension’s experts have answers! Send your questions and photos to Ask an Expert.

Q&A: What causes orchid leaves to turn yellow and shrivel?

orchid with yellowing leaves

Q: Why are my orchid leaves turning yellow and drying up? The plants are located in the bathtub where they get sun daily from the south and west window.

A: While it is normal for the oldest leaves of moth orchids (Phalaenopsis) to turn yellow and dry up as they age, when there is uniform yellowing and shriveling of newer leaves, it is a sign of distress. The shriveling suggests there is a lack of water reaching the leaves. Check the root system of your plant. If the roots are in poor condition, they cannot take up water. Overwatering can cause roots to rot. If you haven’t repotted your orchid in a couple years, the potting medium may have broken down and become too dense to allow for good drainage. Bacterial rot also can occur if water is allowed to sit around the center shoot or in the leaf sheaths for a long period of time. Water only in the morning so that your plants can dry out by nightfall. Never let them stand in water and keep the plants in a location where they can get good air circulation, indirect light, and a warm daytime temperature above 75F. Watering instructions can be found in our orchid care video.

See additional information on Phalaenopsis orchid care on the Home & Garden Information Center website.

By Christa K. Carignan, Maryland Certified Professional Horticulturist, Coordinator, University of Maryland Extension Home & Garden Information Center

7 Cheery Blooming Houseplants to Help You Beat the Winter Blues

The winter doldrums have settled in and as we count down the days to spring, why not brighten up your interior spaces with houseplants? Blooming plants cheer up a room with pops of color. Popular as gifts, their big advantage over cut flowers is that they are longer-lasting. And sometimes, given proper care, they can even bloom again.

Easy Blooming Houseplants

anthurium
Anthurium Photo: D. Ricigliano

Anthurium (Anthurium andraeanum)
The striking long-lasting flowers of this houseplant provide the color while the dark green, leathery, arrow-shaped leaves are attractive on their own. Botanically speaking, the flowers consist of a hood-like spathe surrounding a twisted spadix. They come in shades of white, red, pink, and, occasionally, orange. Easy care anthuriums bloom in medium light locations. During active growth periods, keep the soil moist and fertilize with a standard houseplant fertilizer in spring and summer.

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