What Is Triangle Palm?
The triangle palm (howea forsteriana) is a popular indoor palm with thin, willowy leaves that can reach up to 5 feet tall at maturity. The triangular shape of the leaves has led to the name “triangle palm” and it is from Australia where the species originates. However, it is now widely grown in tropical regions around the world as an exotic houseplant.
Triangle Palm Care & Maintenance:
The triangle palm is a very easy plant to maintain, especially in the first few years after you get it. It can sometimes be susceptible to spider mites or whiteflies, but that’s not too troubling compared with some other plants.
Light Requirements:
The triangle palm requires medium to bright light. The older the plant gets, the more direct sunlight it will require (up to 4 hours every day).
Water Requirements:
It’s a good idea to water your plant regularly, but don’t overwater. It prefers moist soil and can tolerate dry soil as well as standing water. The triangle palm should be allowed to dry out a bit between waterings.
You’ll know it’s time to water again when the soil feels just slightly dry on top. Thoroughly drench the soil and allow it to drain until there are no more excess water droplets from the bottom of the pot (usually within 24 hours).
If you don’t have great drainage, then do this step in stages by watering only once every few days instead of all at once so that the plant doesn’t sit in soggy soil for long periods (which often promotes root rot).
Fertilizer Requirements:
Feed this plant quarterly with a balanced houseplant fertilizer or palm fertilizer like Palm Booster. Fertilize once in spring when you begin watering again, then do so once more at mid-summer and one last time just before wintertime dormancy. You can fertilize monthly during its active growing period which is spring through summer and fall. Use liquid fertilizer for best results.
You should start to see new leaves emerge every year (or two). When this happens, you can tip prune your triangle palm by roughly 10% and it will grow back fuller and bushier the following year.
It’s also important to note that fertilizers high in nitrogen like Miracle-Gro have been known to cause rapid growth on palms and this may make them more susceptible to spider mites or whiteflies. Avoid using these types of fertilizer when possible. If you really want to use a fertilizer with more nitrogen than usual, use a weak solution (such as 1/4 strength) so the plant isn’t shocked by too much nitrogen at once.
Finally, if the plant does get spider mites or whiteflies, you can use neem oil or insecticidal soap to take care of the problem.
Soil Requirements:
The triangle palm should be planted in fine, medium orchid bark with 1/3 sphagnum peat moss mixed in. There’s no need to fertilize the soil since it will add enough nitrogen for the plant if you’re using a fertilizer that contains nitrogen (like all-purpose houseplant food).
Be careful not to overwater your plant as this can cause root rot. Water until water drains out of the bottom of the pot and allow it to dry out before watering again.
Temperature and Humidity Requirements:
The triangle palm thrives in temperatures around 65-75 F at night and 70-85 F during the day. It is considered a succulent plant, so it prefers cooler temperatures than other plants.
If you don’t have AC or fans, then place it near a window or outside on a shaded patio in summer if your house gets too hot.
Toxicity of Howea forsteriana:
This plant is toxic to cats (and dogs) due to calcium oxalate crystals that are found in many stem and leaf stems as well as some flowers. If consumed by pets, they can cause irritation of the mouth and tongue as well as swelling of the lips, tongue, and throat area which may lead to difficulty breathing within severe cases.
Lastly, it’s important to note that some people are highly allergic to this plant and may have severe reactions if they come in contact with it. It is best to test for allergies before exposing yourself to Howea forsteriana regularly to avoid any issues down the road.
Fertilizing Requirements:
Because it’s a succulent plant, it prefers less fertilizer and more water.
However, if you want to fertilize it or have recently transplanted your Triangle Palm indoors from outdoors, then you’ll need to begin feeding with a slow-release houseplant fertilizer like Miracle-Gro Indoor Plant Food Plus Kelp.
Feed monthly during the growing season (spring through summer) and then only once every few months in winter before transitioning back outdoors in late spring when there is warmer weather.
Potting and repotting Requirements:
The triangle palm shouldn’t be repotted until it has outgrown its current container. You can keep it in the same pot for several years but when you do need to repot, use a pot that is 1″ larger.
You can also transplant into a slightly bigger planter if you don’t want to buy another pot. Make sure the new planter has drainage holes so water doesn’t collect and rot your plant’s roots.
It’s best to avoid using clay pots as they tend to dry out very quickly and will not retain moisture well (especially during cold winter months). Instead, use plastic or ceramic pots that have good drainage and allow excess water to drain freely from your plant’s root area between watering sessions.
Humidity and Air Circulation Requirements:
The triangle palm thrives in humid areas of the home. If you live in an arid climate where there’s little humidity, then keep it on a shaded patio or near a window facing east or west during summer months to give it more humidity while outdoors.
For winter care, it is best to bring your plant indoors and place it near an eastern-facing window with good sunlight exposure. It will need moderate air circulation since stagnant air can cause mildew and other issues that may harm your plant.
Sunlight Requirements:
If you’re growing the Triangle Palm from seed, then a south-facing windowsill is ideal for germination. After the plant has sprouted, move it to a full-sun location and continue to keep it outdoors in direct sunlight.
The Triangle Palm should get at least 4 hours of direct sunlight every day during the summer months indoors but can also thrive on a shady patio during winters if you don’t have any good windows for optimal sunlight exposure.
It’s important that you make sure your plant gets enough light or else it may lose its lush green color and drop leaves. Also, this is a slow-growing plant so it will take several years before you need to think about moving it outdoors permanently in order to avoid scorching the leaves due to too much sun exposure over time.
Triangle Palm Propagation info:
You may propagate by taking tip cuttings from the triangle palm during summertime when new leaves emerge. You’ll know which ones are good because the other leaves will start turning brown around them making it easy to see which ones to take.
If you want to try rooting the triangle palm in water, you will have better results doing so outdoors because it will only survive indoors for a couple of months before quickly dying. However, if you do choose to root it in water inside, use distilled water instead of tap water and don’t fertilize until the new plant is well established.
Place the tip in the water and let it soak for several weeks then plant it in a planter or soil after roots begin forming. This may take anywhere from one month to many years depending on whether or not your plant was actively growing at the time of propagation.
Triangle Palm Pests and Diseases
If you’re dealing with pests or diseases on your triangle palm, here are some natural ways to treat them without using chemicals:
Spider Mites & Whiteflies – Neem oil and insecticidal soap work great for these guys as they don’t like strong smells (insecticidal soap also works for aphids). Scale Insects – Scale insects can sometimes be removed by simply dabbing them with rubbing alcohol on a cotton swab.
Mealybugs – These can be removed manually by dabbing them with rubbing alcohol on a cotton swab. Brown Sap Spots & Drooping Leaves – This may be due to root rot so try digging up the plant and repotting it in fresh soil if you notice brown spots or drooping leaves.
If you’re still having issues, move the plant outdoors for the winter since most pests and diseases will die during cold months of dormancy. In springtime, bring your triangle palm back indoors before any new pest problems arise again outside which may cause the leaves to turn brown once more due to over-exposure to harmful UV rays from sunlight (which can kill these types of plants).
Triangle Palm Problems:
Drooping Leaves – This may be due to over-watering so try cutting back on watering or repotting it in new soil.
Brown Spots & Dying Leaves – The leaves could have been burnt by direct sunlight which can kill the plant if left exposed for too long (if your triangle palm is outdoors).
If you notice brown spots and dying leaves, try moving the triangle palm to a shaded area or indoors during summer months while still bringing it outside each night before sundown for at least 4 hours of sunlight exposure per day.
