Hoya are known for their beautiful foliage – making them a popular choice among houseplant enthusiasts. Also known as a wax plant, wax vine, and waxflower – Hoyas are also grown indoors for their beautiful, sweet-scented blooms – each different and unique depending on their variety.
While Hoyas are relatively easy to care for, they are not immune to many common houseplant issues. This blog will go through a few of the most common houseplant issues that could be affecting your Hoya, how to identify as well as troubleshoot them.
Common houseplant issues that affect Hoyas include overwatering, poor drainage, temperature stress, pests, and disease. Getting care and the growing environment right for your Hoya can help mitigate most of these issues.
Yellow Hoya leaves can be indicative of a couple of issues potentially impacting your houseplant. Giving context to the origins of Hoyas will help you to better understand the types of growing environments they tend to thrive in.
Like most tropical houseplants, Hoyas enjoy bright light and warm humidity. Native to Asia and Australia, Hoyas are epiphytes and grow on trees – using their trees and branches to hoist themselves and grow upwards.
Trying to emulate a similar environment when growing Hoya can help to ensure the health of your Hoya and prevent yellow Hoya leaves from occurring.
Unfortunately, once leaves begin to turn yellow it is very unlikely that they can be salvaged. We do not recommend pruning or removing leaves that are beginning to turn yellow as the plant is transferring nutrients out of it before it lets the leaf go. But do not despair! New growth can still occur once you identify and resolve the issue that led to the yellow leaves in the first place.
Overwatering and Poor Drainage
Hoyas do best with a light watering hand as too much water and poor draining potting mix can negatively affect their root system – which will impact the entire plant. Roots require oxygen and airflow, which is why using a well-draining potting mix is essential for ensuring your Hoya’s continued growth.
Allow the first 2 inches of the soil to dry out completely in between waterings. If you are unsure, you can stick your finger in the soil to feel for moisture. You can also choose to use a moisture meter to test the moisture of the soil – however, we recommend sticking the indicator into the soil a couple of times to get the most accurate reading.
When Hoyas receive too much water and poor drainage, chlorophyll will break down in the leaves – which causes the yellowing you see. If you notice that the bottom leaves of your Hoya are turning yellow first, test the soil and check for moisture. Also, look at your pot – is there a draining hole to allow excess water to pass through?
If the potting mix is soggy (or stays soggy after watering several days later) and/or there is no drainage hole at the bottom of your pot – it is time to re-pot your plant or otherwise deal with the perils of root rot. Repotting will allow you to assess your Hoyas roots. Are they brown and mushy? If yes, then root rot is likely the culprit.
Any brown mushy roots will need to be cut off. Place the remaining healthy roots in a container of 1 part rubbing alcohol to 3 parts water. This will help sterilize the roots. Leave in the mixture for 45 minutes – 1 hour. Repot in well-draining, chunky potting mix with a drainage hole. Just a heads up – if you have removed a good portion of the root system due to root rot, you can expect that many of the leaves will also fall off.
While overwatering is the common culprit to the demise of the Hoya, underwatering could also be the reason why your Hoya’s leaves are turning yellow. Even though Hoyas can tolerate dry conditions, if you are watering your Hoya too infrequently, its leaves can and will turn yellow.
You’ll also know that you’re underwatering your Hoya just by doing a quick physical assessment – the entire plant will look dehydrated. To fix this, start watering your Hoya more regularly. Keep track of the frequency in which you water your Hoya by using a notebook, calendar, or even an app to keep yourself accountable.
Too Little Light, Too Much Light, Light That’s Just Right
Hoyas prefer bright light and tend to do well in East and West facing windows, or a few steps back from a south-facing window (but keep in mind that the lighting will change depending on the season). However, too much direct sunlight can damage and burn their leaves. Yellowing of the leaves, as well as browning of the tips of the leaves, can indicate that your Hoya has been exposed to too much direct sunlight.
Hoyas tend to not do as well in low light conditions. Before leaves begin to turn yellow, the leaves will become greener or revert to green depending on the variety of Hoya you have as they try to absorb as much light as they can.
Unfortunately, improper lighting can also lead to the demise of your Hoya’s health – as poor lighting means it is unable to sustain its foliage growth. If you’re worried about your plant’s lighting conditions being too low – consider opting for a grow light to supplement and provide your Hoya with the light it needs to grow.
Getting the Nutrition Right
Nitrogen deficiency is a common culprit of yellow leaves in Hoyas. You’ll be able to identify if a nitrogen deficiency is occurring in your Hoya by looking at the texture and feel of the leaves – soft, limp and weak.
Nitrogen deficiency is caused by insufficient nutrients in the potting mix – if it’s been a while since you last repotted your Hoya, it might be time to consider fertilizing or re-potting in a new nutrient-rich potting mix. Most mixes have sufficient nutrients to last the plant for a couple of years.
If you’re opting for the fertilizer route, keep frequency in mind. In the growing season (spring through summer) you’ll need to fertilize your houseplant more frequently than in the fall and winter months. Be sure to follow the instructions of the fertilizer you use carefully, as over-fertilizing can lead to other issues.
Acclimating Your Hoya and Yellow Leaves
Yellowing leaves in Hoyas due to acclimation are the result of stresses associated with a change in the plant’s growing conditions. This is typical of new plants you are introducing to your home environment – as they get used to not being in their previous nursery conditions. Acclimation stress can also occur when the season changes – especially in the transition from summer to fall.
What usually happens is that the oldest leaves of the plant will yellow and fall off first. If multiple leaves are falling off in a short time, it might be time to reassess the growing conditions – ensuring your Hoya is receiving the optimal growing conditions for it to thrive (bright light, infrequent watering, chunky well-draining soil mix).
Old Foliage Yellowing
Hoyas can shed old leaves when it prioritizes new growth. If you see new growth points as your Hoya leaves a couple (few) leaves – this should not be a cause of alarm.
However, if there are no new growth points and multiple leaves are yellowing and falling off – it is time to reassess the conditions of your Hoya and make adjustments based on what you find.
In sum, yellow leaves on your Hoya can be the result of a myriad of causes – from lighting, potting mix, watering, fertilization, and acclimation – you will need to identify the why before you can make the correct adjustments to ensure your Hoya’s continued growth.
When in doubt, just keep in mind the native growing conditions of Hoyas and how they translate when growing them indoors – bright light as well as allowing the potting mix to dry completely between waterings are a good place to start when troubleshooting your Hoya’s yellow leaves.
And if dealing with your Hoya’s yellow leaves becomes more of a burden, do not worry! You are not a bad plant parent for not being able to figure out what was wrong with your houseplant. We wish you all the best with identifying and resolving the issues with your Hoya houseplant.