15 Tips For Growing Beautiful Orchid Flowers Indoors
Orchids can be picky about their growing conditions, which makes them great indoor flowers. There are also a few things you can do to maximize their blooms. In this article, gardening expert Melissa Strauss shares her top tips for growing beautiful orchids indoors!
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Orchids have quite a reputation for being fussy and difficult to grow indoors. In the wild, orchids require little more than a tree to grow on and regular rainfall and humidity. In their native environment, thriving orchids can produce thousands of flowers in their lifetime. Inside a home, they require considerably more effort to encourage those wonderful blooms.
If you have decided to undertake growing orchids indoors, there are a few important factors to consider, and implement. Caring for these plants indoors requires attentiveness and plenty of patience.
Once the right balance has been struck, your orchids should be well on their way to producing those coveted flowers. Here are some tips for creating the right environment for optimal orchid growing.
Terms to Know
- Epiphytic: Non-parasitic plants that grow on trees
- Lithophytic: Plants that grow on rocks
- Terrestrial: Plants that grow in the earth
- Monopodial: growing from one central rhizome, vertically.
- Sympodial: Growing from a central rhizome which moves horizontally.
- Labellum: The bottom petal on an orchid bloom, also called the “lip.”
- Aerial: growing in the air
- Rhizome: Central root from which all growth occurs.
- Pseudobulb: produced by sympodial orchids.
First, Identify the Species
The first step in caring for an orchid is determining what type of orchid you have. The most common types that people keep as houseplants are:
Cattleya
These sympodial epiphytic orchids are commonly known as “Corsage Orchids.” They produce pseudobulbs along their central rhizome. Each pseudobulb has one to two, long, narrow, sturdy leaves and produces one to two flowers. The flowers are generally showy and fragrant with a striking and pronounced labellum.
Phalaenopsis
Also known as “Moth Orchids” these monopodial epiphytes are probably the most common type kept as house plants. They have large, elliptical leaves and grow tall stems with 5-10 blooms on each stem. The flowers have rounded petals and a lip that resembles a serpent’s mouth.
Epidendrum
These are sympodial orchids, some are epiphytic, and some are terrestrial. Epidendrum orchids produce long thin pseudobulbs or canes, which grow many leaves that are short in relationship to the height of the cane. Atop each cane, they produce clusters of small fragrant flowers in a variety of colors.
Oncidium
Also called “Dancing Lady Orchids,” oncidium orchids are sympodial and epiphytic. They grow long, flexible, grass like leaves from each pseudobulb. Leaves tend to have vertical ridges. Flowers grow prolifically on long, thin spikes. The blooms have a large, ruffled labellum that resembles a full skirt, giving them their nickname.
Dendrobium
This species can be epiphytic or lithophytic and is sympodial. They have a wide variety of floral structures and growth habits. Flowers grow on tall canes, which, in some cases lose their leaves after blooming, and produce new flowers where the leaves have fallen from. This deciduous habit is unique to this species as most orchids do not lose their leaves seasonally.
Spathoglottis
Commonly called “Ground Orchids,” they are terrestrial and sympodial. They grow in the ground and their leaves are long, pleated and grass like. Pseudobulbs send up tall stems which can bear more than 2 dozen flowers each in some varieties. The name comes from the Greek words for flower and tongue because the shape of the labellum.
Vanda
Vanda orchids tend to fare better in greenhouses because of their high humidity needs. They are true epiphytes and can grow without any planting medium at all. They do quite well when grown in a wire basket or on a hook. Vandas are sympodial in growth habit and form lots of long aerial roots that hang down gracefully from the central rhizome. The vanda is also one of the only types that has a true-blue colored bloom. All other blue-blooming orchids aren’t real.
Once you’ve identified the species you’ve decided to grow, then it’s on to each important factor that can impact both their growth, and their blooms.
Use the Right Planting Medium
Because of their epiphytic nature, orchids need a lot of air circulation around their roots. As such, regular potting mix will hold too much water and most likely cause the roots to rot. The objective in choosing a potting medium is to mimic the growing conditions of the plant in its native habitat.
Orchid bark potting mix is commercially available at most landscaping and gardening stores, but if you like to mix your own, they are predominantly made up of bark mixed with a bit of charcoal and pumice or sponge rock.
Some orchids may come potted in sphagnum moss or peat moss. These mosses tend to hold more moisture and inhibit air circulation around the roots of the plant. They are good for growing and propagating young plants, but mature plants store water well and do better with either a moss/bark mixture, or no moss at all.
Choose the Right Container
In addition to the right potting mix, the container or pot that you choose for your orchid is very important. The main requirement of an orchid container is its drainage capability. There are three common types of orchid pots sold commercially.
Baskets made from wood or plastic are great for hanging indoor plants. This most closely mimics the natural habitat of an epiphytic plant and allows for maximum air flow. However, they can be a bit messy and need to be taken down to water them if kept inside.
Terracotta pots look like standard flower pots, but they have large drainage holes on the bottom and sides, to allow for that good air circulation. Terracotta has the added benefit of wicking moisture, which helps to prevent rotting orchid roots.
Ceramic pots are more decorative and visually attractive, so they are a top choice for orchids grown as houseplants. They look like regular ceramic pots, but with holes on the sides, usually forming an attractive pattern of some kind. It is important to note that if your pot holds water in an attached dish, it will need to be drained after watering, as an their roots should never sit in water.
Provide the Right Amount of Light
This comes down to knowing your species more than any other factor. Some orchids need almost full shade, while some will not bloom without several hours of bright light daily. Consider where your plant grows in nature and try to emulate that type of lighting.
Most are epiphytic and will grow on trees in tropical and sub-tropical climates. This means they will do well in bright, but indirect sunlight, or dappled sunlight.
Phalaenopsis orchids are best for low-light spaces. They grow in the shade, so they don’t need as much light to produce blooms. Vanda, cattleya, and dendrobium orchids all enjoy several hours of direct, morning sunlight, but need protection from hot afternoon sun. For most other species, the rule is bright, but indirect light for most of the day.
Maintain the Right Temperature
Orchids are sensitive to temperature shifts. This is a factor that makes them good houseplants, as most homes do not experience vast shifts in temperature from daytime to night. Temperature shifts should be accounted for with plants that live outside most of the year.
If you keep your plants outdoors in the warm seasons, be sure to bring them inside during times of extreme temperature shifts, and if the temperature drops below 40°. If you can identify the region where your orchid grows naturally, it should be fairly simple to determine its temperature needs.
Orchids are classified as cool- intermediate– and warm-growing depending on their needs. Most orchids in all categories tolerate high heat in the summer, in temperatures of 100° and higher, they will need more shade and more water to keep from burning or drying out.
Cymbidium orchids require a shift to cool temperatures in the fall to produce buds, so they are considered cool-growing. Spring blooming Cattleyas also have this need for cooler autumn weather to induce buds to form. Dendrobium orchids are considered warm-growing plants. And phalaenopsis are intermediate-growing.
Provide the Enough Humidity
Orchids are predominantly native to tropical and sub-tropical climates. If you’ve ever vacationed in a tropical climate, you know that, outdoors, they have much higher humidity than most people prefer inside their homes. They absorb much of their water and nutrients from the air around them, so their need for humidity is high.
A good rule of thumb in terms humidity needs is 60-80%. On the higher end is preferable. A sunny bathroom window is just about the perfect indoor location. If your orchids are in a room with less humidity, you can raise the levels in one of a few ways.
Orchids can be misted, a humidifier can be used, or a plate of water be placed beneath the plant. When using the last method, use stones to elevate the pot, making sure that the roots of the plant never sit in the water. A lack of humidity can cause wilted leaves or a dying plant.
Avoid Overwatering
Orchids have somewhat specific watering needs when kept as houseplants. The main cause of plant death for indoor plants is overwatering. Overwatering causes root rot and encourages the growth of fungus and bacteria around the foundation of the plant.
If their roots are kept damp or soggy, they will weaken and eventually rot. If you notice your orchid’s leaves turning yellow, there is a good chance you are giving it more water than it needs. A good rule of thumb for watering is to water once per week through the dormant months and allowing the potting medium to dry completely between waterings.
During the blooming season, it’s ok to water twice per week, because the blooms will last longer if they have an adequate supply of clean water
Avoid Underwatering
Underwatering, likewise, can kill an orchid. Orchids do a good job of getting what they need from the air around them, but if the humidity isn’t quite right and their roots are deprived of water for too long, they will use up their reserves and the leaves will crinkle and dry out.
It is easier to revive a dry plant than one with root rot, so I try to err on the side of watering less and misting more, but typically, indoor plants a good soaking once per week, with the opportunity for potting medium to dry out between waterings.
If you keep your orchids outdoors during the warm months, they will need to be watered more frequently. My outdoor orchids like to be watered every 2 or 3 days.
Fertilize, Fertilize, Fertilize
Indoor orchids need to be fertilized regularly to perform at their peak flower production. Fertilizer specific to the species is commercially available, but a balanced fertilizer (20-20-20 works well) can be diluted to about ½ strength and will work just fine if you have that on hand.
During their blooming season, they like to be fertilized about once every two weeks. So, every second time you water, you should fertilize. While dormant, you can reduce the frequency of fertilizing by half, cutting down to once per month.
Inspect for Diseases and Pests
Try to make a habit of inspecting for pests and diseases when you water them. The best defenses against pests and diseases are early diagnosis, and swift treatment. If you know what healthy growth looks like, it is easier to recognize when something is wrong, so familiarize yourself with what your orchid should look like, in optimal conditions.
Most of the diseases that cause damage and death are fungus related. A majority of these issues become noticeable first on the leaves of the plant. Brown spots, or general yellowing of the leaves are strong indicators of root and leaf rot.
Treatment for fungal infections involves cutting away the damaged roots and tissue, treating for fungus and repotting in uninfected potting medium. Powdered sulfur makes a great treatment for treating freshly cut roots and other plant parts.
There are several insects that enjoy feeding on orchids. Scale, mealybugs, mites, and aphids are among the most common. Signs of an insect infestation manifest as damaged and destroyed blooms, as well as pitting and faded spots on leaves. These pests can be taken care of by wiping leaves and stems with isopropyl alcohol on a cotton swab.
Encourage Reblooming
Encouraging your orchid to rebloom encompasses all of these best practices, as well as some strategic pruning. To encourage new growth, locate the lowest node on the stem after flowers have fallen.
Trim the stem off one inch above this node. This will encourage the node to send off a new stem, and new stems mean more flowers!
Provide Post Bloom Care
There are a few maintenance choices to be made after the blooms have fallen. The first, is to do nothing. If the plant is heathy and the spike or stem remains green and flexible, there is no harm in leaving it alone.
You can trim the spike to encourage a new shoot. As I mentioned above, cutting the stem just above the lowest node will encourage the plant to grow from that spot, and can even result in a second blooming stalk forming in the same season.
If the stem turns yellow or brown, it is best to trim it off completely, as once this has occurred, it will no longer bloom. Be very careful in doing this to sympodial orchids that you do not cut off the entire pseudobulb, as these store water and nutrients to encourage and nourish new growth.
Providing post-bloom care is essential to keeping your orchids around for longer than a single season. Orchids are perennial in nature, and can bring you decades of blooms if given proper care.
Prune and Repot at the Right Time
In general, the best time to prune and repot a plant is immediately after it has finished blooming. Repotting while in bloom will almost certainly reduce the life of the blooms, and those flowers are a lot of work, so you want to enjoy them for as long as possible. Pruning is generally not necessary unless there is damaged growth or roots.
Technically, an orchid can be repotted any time that it is not in bloom. If you are repotting to propagate, a monopodial orchid can be cut along the rhizome in any spot that leaves at least 2 leaves intact on both portions.
A sympodial orchid can be propagated by slicing the rhizome between any 2 pseudobulbs. For the best results, and fastest recovery, try not to divide sympodial orchids with fewer than 4 pseudobulbs, new or spent, on each new plant.
Always Clean Your Tools
This is a piece of advice that you will read over and over, in any plant guide, for all plants. The most important factor in pruning and repotting a plant is proper hygiene. The fastest way to spread diseases and pests is by using tools on infected plants, and then not sterilizing before using on a healthy plant.
Your tools should be clean and sharp. Making clean cuts is important because a clean cut heals faster, which helps protect the plant from disease.
Check the Roots When Repotting
Finally, when repotting an, check out those roots. The appearance of an orchid’s roots will tell you a lot about the general health of the plant. If an orchid is getting too much water, or the potting medium is staying too moist, the roots may begin to rot. Rotted roots will be dark brown and mushy.
If an orchid is not getting enough water, the roots will be dry and brittle, and crumble easily. If your plant is drying out, try adding a bit of peat moss to the new potting mix, this will help retain moisture. Increasing the humidity will also help prevent the roots from drying out.
Healthy roots are light green to white. They should be somewhat flexible and you should be able to disentangle them from old potting medium with relative ease.
Final Thoughts
Orchids are definitely a high maintenance plant to grow outside of their native habitat, which includes zones 10-12, and sometimes 9. Striking the right balance of moisture, light and nutrients can be a challenge when you’re starting out with these rather particular plants.
While they are complicated to care for, familiarization with their native habitat and needs is a step in the right direction. The process is involved, but the payoff is so worth it. Orchid flowers are some of the most beautiful and unique blooms in the plant world.
