Sometimes we get questions that sound more complicated than they really are. After observing an odd occurence in my own home, I’ve been contemplating this one: “Why is my Thanksgiving Cactus blooming in March?” Sometimes, it’s a very simple answer: Because it’s not a Thanksgiving Cactus – it’s an Easter Cactus.
However, that’s not the case for MY cactus. Using the image below, I’ve correctly identified my plant as a Thanksgiving Cactus (Schlumbergera truncata) based on its leaf structure. It also bloomed profusely last fall. So what gives?
A couple of weeks ago, while watering, I noticed that some buds were forming on the window side of the plant, but not on the other side facing me. I turned the plant around. A few weeks later, it’s “bloom city” on that side, but the other side has exactly zero blooms.
I did some investigation, and it turns out that blooms require two things: cooler temperatures and long nights. These cacti are short-day plants, which means that blooms are triggered by long dark cool nights. They need for between 14-16 hours of uninterrupted darkness and 8 hours of daylight for between 3 – 6 weeks to set flower buds. Our winter seems to fit that bill — flowering that shows at Thanksgiving will often be followed by a second rush just before, at, or maybe after Easter because of the light and temperature.
Once you notice that your cactus is budding or re-budding, it’s a really good idea to leave it in exactly the same place, and to not move it. Moving the plant may result in bud drop. Also, while in flower, allow the soil to dry down somewhat between waterings.
Many plants will root well in water but some, like Streptocarpus, will form stringy, fibrous roots that may have difficulty becoming established when planted in soil. That is why a leaf cutting is advised. It is quite an amazing process as both leaves and roots are formed and the leaf cutting does not become part of the new plant.
You should have all your equipment clean and ready. Take a healthy leaf from a well hydrated plant and either cut out the midrib of the leaf, creating two leaf pieces or cut the leaf into 5cm sections from top to bottom. Have a clean pot already prepared with moistened soilless potting mix or half and half potting mix and perlite (medium). Your moistened medium should still be crumbly, not forming clumps, as that may mean it is too wet and may cause your leaf cutting to rot. Take your leaf cuttings and place them in the soil. Placing them about 2.5cm deep is advised but my leaf cutting wasn’t that big. As you can see parts of the leaf curled up but I still managed to get results. Five plantlets so far!
After your cuttings are in the soil, place your pot in a plastic bag to keep the humidity high. Leaf cuttings have no roots to support them so they need the high humidity. Place your bagged pot in a warm, bright spot but not in direct sun. It is advised to open the bag every week to release excess humidity and to water as needed. You may find you never need to water while the pot is bagged.
In about 6-12 weeks you will hopefully have little plantlets forming. Wait until they have developed enough leaf and root tissue and then pot on to 3-4” pots and enjoy your new plants.
Seeing bugs outside is generally pretty tolerable as we know that many of them are pollinators, but seeing them inside our houses is a completely different story, right? Fortunately, it’s usually easy to manage most indoor pests with little more than some water, a cotton swab, and a soap solution. It all starts with a few preventative actions:
Whenever you happily bring home a new treasure (or sometimes, victim!), make sure that you carefully inspect them. Many types of houseplant bugs piggyback their way into your house from friend’s homes or stores. Look on leaf undersides, along the stems, and even in the soil for signs of common pests (sticky substances, flying cloud when disturbed, little bumps, fine silky webbing).
Put your new treasure in solitary confinement for a few weeks, like in a spare room. Even if you think a new plant is pest-free, it may have pest eggs or larvae that you can’t yet see. Watch it carefully and only put it in close contact with other plants after it’s been confirmed to be pest-free. If the pandemic has taught us anything, quarantining is right at the top of the list and it applies to plants as well as humans.
Place a few yellow sticky cards in among your plants. Many pest insects are attracted to the color yellow, and they’ll quickly get trapped on the card. Check the card every few days for any insects. If you have some on the card, you probably have many more on the plant itself.
For all infestations, the first thing to do is to move the affected plant away from all other plants. Quarantine!
Then, take the plant to the bathtub/shower and spray it with water. Many bugs are tiny and are easily washed off the plant. Be sure to rinse both upper and lower leaf surfaces. After the plant has fully dried, use a light-weight horticultural oil or insecticidal soap to smother the pests. Reapply the oil/soap every 10-14 days for two more applications for the best control.
If you detect small bumps, wipe the plants with a cotton ball soaked in rubbing alcohol and remove the bumps if possible.
If you detect pests in the soil, it’s often caused by overwatering. Reducing the amount of water, or watering your plants from the bottom instead of the top should take care of the problem. Spraying the soil lightly with insecticidal soap occasionally often helps as well.
We turn to searching for information online or in books on how to care for our plants. Unfortunately there are a lot of inaccuracies surrounding certain beliefs and practices concerning them. Since most of our attention is now focused on indoor gardening, let’s look at five questions concerning houseplants.
1. Are Poinsettias Poisonous?
You may have been gifted with a Poinsettia (Euphorbia pulcherrima) and you may be concerned because you have heard that they are poisonous. The plant, while not edible, would need to be consumed in large quantities to be harmful. That being said, it still is wise to keep the plants out of reach of pets and children as some consumption may lead to digestive distress. Like other members of the Euphorbiaceae family, Poinsettias produce a milky sap and so handling the plant without gloves may affect those with a latex allergy.1
2. Can Houseplants Filter or Absorb Pollutants?
Recently I read in a book on houseplant care that plants draw in harmful volatile organic compounds (VOCs) such as formaldehyde and benzene and clean the air for us. Two examples mentioned included the Peace Lily (Spathiphyllum) and the Spider plant (Chlorophytum comosum). It stated that the former can filter out formaldehyde and the latter both formaldehyde and benzene. While it is true that plants have the ability to absorb pollutants, large numbers are required to have a significant impact. The belief that plants clean the air may be associated with a single NASA study2 from the 1980s that was conducted in an air-controlled laboratory setting and not in an open home or office setting. More recent research has determined that a building’s air handling system or open windows is more effective at reducing pollutants than plants. One would require 10-1000 plants per square meter in order to be comparable.3
3. Will Misting and Pebble Trays Increase Humidity?
We may struggle with maintaining optimum humidity levels in the winter for our tropical houseplants. Many books and online sources recommend increasing relative humidity around plants through misting and placing the plant pots on trays filled with pebbles and water. Misting is generally ineffective because the water evaporates so quickly. It would have to be done constantly to have an impact. Concerning pebble trays, an experiment published in the American Orchid Society Bulletin found that in the winter (set in a home in Minnesota), relative humidity levels were raised only slightly. The RH at 40 mm above the tray was measured at 3%; at 110 mm 2%; and at 300 mm it measured 0%.4 Using a humidifier is really the only method that has the ability to increase humidity levels significantly.
4. Should you Use Ice Cubes for Watering Orchids?
Recently I read a comment on the Master Gardeners of Ontario Facebook site that someone said that their Moth Orchid (Phalaenopsis) came with a tag advising them to use ice cubes as a method of watering it. It seems that this advice is really intended to help prevent new Orchid owners from overwatering their plants. While there is a study that found that using ice cubes did not negatively affect the health of the orchids, it was only conducted for a period of 4-6 months. A problem with using ice cubes is that it has the potential to accumulate salt build-up (from water and fertilizer) that can affect the plant’s longevity in the long term.5
5. Should you use Leaf Shining Products or Oils?
Some sources advise using commercial shine products or oils to help make a plant’s leaves shiny and reduce build-up of dust. However, there is research indicating that the use of leaf shine on Weeping Fig (Ficus benjamina) caused the plants to have a reduced tolerance to low light stress, resulting in three times as much leaf loss as untreated plants.Treated plants required higher light levels.6 Another problem is that they can block the pores or stomata in the leaves of some plants, resulting in reducing the plant’s ability to photosynthesize and respire.
Cummings, Bryan E. and Michael S. Waring. Potted plants do not improve indoor air quality: a review and analysis of reported VOC removal efficiencies. Journal of Exposure Science & Environmental Epidemiology. Volume 30, pp. 253–261 (2020). Online:https://www.nature.com/articles/s41370-019-0175-9
Kohl, Douglas. A Study in Humidity: Douglas Kohl Evaluates the Effectiveness of a Common Method to Raise Humidity around Orchids Growing in the Home. American Orchid Society Bulletin, 63(8). 1994. pp. 916-917.
If your houseplants are on “vacation” on the back deck this summer, then at around this time you should think about getting them ready to move back inside for the winter.
Bring your houseplants indoors before night time temperatures dip below 7 or 8 degrees (C). Most tropicals will suffer damage at temperatures below 5 degrees, a few even below 10 degrees.
Sudden changes in temperature, light, and humidity can be traumatic to plants, resulting in yellowed leaves, dieback, wilting, and even death. To prevent shock when you bring houseplants back indoors, expose plants gradually to reduced lighting.
Before moving day, inspect plants for insects and diseases, and treat as appropriate before bringing plants back inside. Spray them a couple of times over a 2 week period with a mild soap and water mix so that you don’t bring bugs from outdoors in with your plants. Alternatively, soaking the pot in a tub of lukewarm soapy water for about 15 minutes will force insects out of the soil. Allow the plant and pot to dry completely afterwards. If snails, earthworms, or other insects burrowed in the soil, you might want to repot the plants, placing a piece of wire screening over the drainage hole to keep them out next year.
Personal anecdote: A couple of years ago, I brought a large cactus planter inside without inspections or the soaking method. The next day, we found a curious “deposit” left behind by some unknown critter on our kitchen floor and we kinda freaked out. We set live traps in the house and were on high alert for a chipmunk or squirrel or even something huge with big teeth that could drag us out of bed by the big toe. It was a little bit traumatic. A day or so later, my son found a large toad in the living room and we connected the dots. Turns out that toads leave very large deposits for their body size (Google it!) and closer inspection of the cactus planter showed an open hibernation hole. Whew!
Moral of the story? Check your plant pots for toads too!
Continuing on a similar theme to last week’s blog on Orchids by Master Gardener Cheryl Harrison, I thought I would touch on another family of plants that are tropical and exotic; the Bromeliaceae family. Known as Bromeliads, it is a large family which includes more than 50 genera and at least 2,500 known species which are native mainly from an area stretching from the southern U.S. to Central and South America.
Before COVID, we would do an annual visit to the Sarasota area in Florida. One of my favourite places to visit is the Marie Selby Botanical Gardens. Selby Garden botanists have made hundreds of expeditions into the tropics and subtropics and have contributed to the most diverse living and preserved collection of epiphytes in the world. They have a greenhouse that is beautiful to walk through with very knowledgeable volunteers to answer questions.
Many bromeliads are stiff-leaved, rosette-forming plants with brightly coloured leaves, bracts and flowers. The majority of them are epiphytic, meaning that they grow on the branches of trees without taking nutrients from the tree. They can also be lithophytic which means they reside on rocks, and the remaining are generally terrestrial, meaning that they grow in soil. Bromeliad flowers can last several months, but they generally only bloom once. The mother plant will produce new plantlets, also called ‘pups’. They are incredibly resilient but do not like to be overwatered. Their roots are usually used for balance and not for transferring nutrients. Instead, the leaves take in all of the water and nutrients the plant needs. They never breath out carbon dioxide almost as if they hold their breath in order not to lose moisture. It is a very special photosynthesis.
Many bromeliads have leaves that form a reservoir to hold water at their bases (known as tank bromeliads), with the largest holding up to two gallons of water. Types that don’t hold water are called xerophytic or atmospheric bromeliads.
One of the most well-known Bromeliads is in the Ananas genera. This is the pineapple, Ananas comosus. Europeans first found out about bromeliads when Columbus went on his second trip to the New World in 1493. The pineapple was being cultivated by the Carib tribe in the West Indies. After colonization, it was rapidly transported to all areas of the tropics and became a very important fruit.
Another genus is Tillandsia. It is the largest group in the family and this genus is also known as “air plants”. Most do not form tanks and have grey-green leaves and are densely covered with fuzzy scales that give the plants their characteristic colour. Tillandsia require more humidity than other bromeliads and tend to dehydrate in the dry air of most homes, but can still be grown successfully with more frequent watering.
Spanish Moss falls under this genus, Tillandsia usneoides. It is very prevalent in Florida and is neither Spanish nor a moss. Unlike other epiphytes that have roots to anchor themselves to their host tree, Spanish moss has tiny scales on its leaves and its curved structure to cling to its host tree. It is important for diversity as its large mats that drip from trees harbor a great variety of insects, birds and bats. In Florida, you usually see Spanish Moss clinging to Live Oaks.
Bromeliads will survive for months or even years under less than ideal conditions. They need satisfactory light, temperature and humidity. It is best to use water that is not softened. You should use a potting mix that holds moisture yet drains quickly. Orchid bark mixed with course perlite and humus is good for most bromeliads. The small air plants only need to be misted with a spray bottle or put in a bowl of water for an hour. If you would like to learn more about these amazing plants, visit University of Wisconsin-Madison.
The idea of growing and caring for orchids may be daunting, but perhaps you would like to try something new. Don’t be afraid! A few years ago, I was seduced by a beautiful, exotic bloom and bought my first orchid. I was very happy to discover that even I could successfully grow orchids!
All of my orchids are Phalaenopsis orchids; these are the easiest ones to grow. I love the airy sound of the Latin name and it suits the common name perfectly which is “moth orchid”. These orchids bloom in many different gorgeous colours and have shiny, thick and leathery green leaves. Their aerial roots are part of what makes them look so exotic. They like the average home’s indoor temperatures and light levels so make great indoor plants.
Phalaenopsis orchids are epiphytes, or air plants, which means that they grow on rocks or trees in their natural, usually tropical or subtropical, habitat. They get much of their water and nutrients from the air. As indoor plants, these orchids will need to be potted in a special potting mix. Orchid potting mix often contains bark, vermiculite, perlite and moss. Regular potting soil retains too much water which will rot the roots of your Phalaenopsis orchid. Orchid pots often have holes in the sides of the pot in order to keep the roots well aerated. This inner orchid pot is then often placed in an outer more decorative pot as shown in the picture above. Orchids need to be repotted every 2-3 years as the bark in the potting mix breaks down. Orchid potting mix is available from many of our local nurseries.
Phalaenopsis orchids do not like direct sun but will do well in indirect light close to an east or west window. You may put them outdoors during the warm summer months but not in direct sunlight. They like high humidity and may benefit from sitting on a drip tray.
I water my orchids once a week. I flood the surface of the potting medium with room temperature, non-chlorinated water until it runs through the bottom of the orchid’s pot. I allow the excess water to drip from the bottom of the orchid pot before placing it back into its outer pot. I have also used ice cubes to water my orchids. Place 2-3 ice cubes on the surface of the potting media, not on the plant, once a week, and let them melt. I know, I know, ice to water a tropical plant??!! The Ohio State University and the University of Georgia did some experimenting to prove that ice cubes will not harm your orchid. Check out the results here (Watering Phalaenopsis orchids with ice cubes) . I do not fertilize my orchids but if you wish to do so here is a link (How do I feed my orchid).
When you purchase your orchid, it may be in full bloom. Don’t just look at that beautiful bloom! Check the plant for signs of poor health, disease and/or pests. The plant’s leaves should be firm, shiny and green not pale and floppy, wrinkled, cracked or missing pieces. There should be no insects living on your plant. If you can, look at the roots in the pot, make sure that they are white/cream coloured. Black/brown roots indicate root rot. The best place to purchase your orchid is from a reputable local nursery. Big box stores may have what appear to be lovely plants but you may bring home more than you bargained for…perhaps pests or disease that will kill your orchid and infect your other indoor plants.
The gorgeous blooms on your orchid will eventually die and drop off. Cut the flower stem back to the node closest to the where the bottom flower was located. The stem may die then you will cut it off close to the parent plant or it may develop into a new flower or a baby plant called a keiki. Cooler night temperatures may encourage reblooming. I move my plants to my cooler basement to encourage them to rebloom. Note that they are still exposed to lots of indirect light during the day in my basement.
Don’t be afraid. Give Phalaenopsis orchids a try. They are well behaved indoor house plants and their blooms are spectacular!
Just 3 short weeks ago I shared my thoughts on the impacts of the coronavirus (COVID-19) on our gardening activities, shortly after the World Health Organization declared it to be a pandemic.
So many events have been cancelled – garden shows, seminars, Seedy Saturdays (and Sundays) – that even the cutest cat photos are not making us feel any better. (yes these are my two cuties – Lulu and Roxy).
Although garden centres and nurseries that grow their own stock are permitted under the conditions of the Emergency Management and Civil Protection Act (as an agricultural activity), many of our favourite nurseries have closed their doors to in-person shopping and resorted to online sales with no-contact pickups at their entrances in order to protect staff and the public.
Fellow gardeners are panicking. After all, this is the time of year when we finally get outside again, clean up our gardens, start seeds, decide on our plans, and look forward to purchasing our favourite plants at the stores.
However, gardening is not cancelled. This year will definitely be different, and we will have to adjust.
In these chaotic times, let gardening be therapy, providing a place for you to find calm and peace.
Working in the soil, with the sun on your face, can take away your worries, at least temporarily. You are using your hands, digging in the dirt, taking in the fresh air, watching the birds flutter around the yard and – best of all – all the news and social media is in the house! Your garden is an escape!
For families with kids at home, gardening offers the opportunity to get the kids outside and busy, while building their self-esteem and bringing variety to what has suddenly become a lot of time spent together. For those on their own you are never truly alone in a garden – there are always birds, bugs, plants or other living things to observe all around you.
COVID-19 is forcing us to re-examine how we live, and how we consume goods and services. This has translated into an increased interest in people wanting to grow their own food, taking us back to World War II, when millions of people cultivated Victory Gardens to protect against potential food shortages while boosting patriotism and morale.
We still don’t know whether we will be able to get starter plants, so many people are ordering seeds. As a result, seed companies are experiencing a deluge of orders, with many stopping new orders until they can catch up. Your local Master Gardener groups and horticultural societies can help you out if you need some advice on how to grow plants from seeds.
Start some seeds.Just seeing something grow out of the soil is a very positive experience. Hopefully you have some seed starter mix around (or can get some) and you can use anything to grow seeds in – from old roasted chicken containers to yogurt cups to folded up newspapers.
Check out social media gardening groups– there are groups out there for every topic under the sun, from seed starting to plant identification to perennials. Since the pandemic began, I have noticed far more people joining these groups, which is wonderful because gardeners just love to share their experiences.
Plan your vegetable garden – figure out which ones you can grow easily from seeds. Learn from others and search Google for ideas.
Stuck inside on a rainy day? Find some online gardening classes or check out YouTube for some good instruction videos on any number of gardening topics.
Get outside for a walk in nature – while maintaining physical distancing, enjoy getting some exercise and seeing all the plants emerging from their winter slumber.
Repot your houseplants. You might just find they reward you with some lovely blooms once we start getting more sunshine.
Hopefully soon we’ll be able to look forward to getting plants at our favourite nurseries (you can be sure they are working very hard to find safe ways to do this). When we do, make sure you support your local nurseries and #buylocal as much as possible.
Until then, find your inner gardening zen, whatever that may be, and enjoy all that spring has to offer. I know I will be sitting by my garden pond, thinking about brighter days ahead.*For best information on the COVID-19 situation contact your local health unit or the Government of Ontario website. Peterborough Public Health, led by Medical Officer of Health Rosana Salvaterra, also has great resources.
African violets are the plants that immediately come to mind when anyone asks me about houseplants. This plant is an old favourite for good reason. I have two. As the name implies, African violets are native to the cloud forests in the mountains of east Africa. Many of the native plants are threatened or endangered due to habitat loss. African violets are not violets (family Violaceae, genus Viola) but are included in the family Gesneriaceae, genus Saintpaulia.
African violets are classified by size from the “Mini” which are less than 7.6 cm (3 inches) in above-ground diameter to the “Giant” which ranges from 30.5 cm – 40.6 cm(12-16 inches). They are pretty plants even when not in flower which they will do almost continuously under good growing conditions. Their flowers may be single, semi-double or even double. This refers to the rows of petals on the flowers. Flower colours include blue/violet, pink, fuchsia, white and bi-coloured. Their dark, green leaves appear velvety because they have a fleshy texture and are covered with fine hairs. The plants maintain a compact form but do come in a trailing form. Lots of choices!
African violets prefer soil that has excellent drainage because the plant may rot if water lays on top or the soil stays water logged. You may purchase specific African violet soil to help ensure a porous growing medium that allows water to percolate through.
Water your plant so that the soil stays moist all of the time but pour off the standing water from the saucer under the plant to prevent the soil from becoming water logged. Do not get water on the leaves of this plant because disfiguring rings will appear where the leaf has been damaged. You may also use a system that allows you to water your African violet from the bottom. This can be as simple as filling the saucer under your plant with water then allowing the plant to absorb water from the saucer. Discard any water left in the sauce after about 45 minutes. Remember to check the surface of the soil to make sure that it is moist … if not, then repeat this process. There are also self-watering pots available. Over-watering or under-watering will damage and may eventually kill your plant.
African violets like bright indirect light. A sunny, warm window is okay in winter but in summer, place your plant in a north or east window or just sit it back from a south or west window so that it does not receive direct sunlight. African violets prefer cooler temperatures at night around18C (60F) and up to 27-29C (80-85F) in the day. Too cool temperatures will stunt their growth.
Like any houseplant, African violets can suffer from some diseases and insect pests including botrytis blight, powdery mildew, mites, mealybug, aphids or thrips. Be sure to purchase your African violet and all of your house plants from a reputable seller to avoid these problems.
With all of the new African violet cultivars and their colourful blooms, why not try one? If you enjoy house plants then the African violet may be the one for you!
Christmas is only a few days away and hopefully you have all your cookies baked, your shopping done, presents wrapped under the tree and your decorations up. Here are a few last minute tips to help you and your plants through the next week.
If you are taking plants to family or friends, bundle them up before putting in a warm car so they won’t be shocked from the drastic temperatures. If you buy a poinsettia, be sure the clerk wraps it well as they are very susceptible to drafts. If you are taking the plant home before you give it away, remove the paper or plastic wrapper to let the plant breathe once you get it into the warmth of your home. Check the soil to be sure it is damp and water if necessary. The same applies to any arrangement you might be transporting. Keep warm and watered so the plants are happy.
If you have leftover cut evergreen pieces, now is the time to use them up. BC cedar and Ontario white pine look the nicest. Make little arrangements for in your bathroom either in oasis or in water. Place stems in vases along with fresh flowers. Lay fresh greens on mantles, side tables or your dinner table. Add stems around your amaryllis bulb or with your paperwhites. You can purchase a WiltProof product which when sprayed sparingly on fresh greens, will prolong their life. Please be mindful of fire hazards when you are decorating with fresh greens.
And have a Merry Christmas and a Happy Holiday Season!