Why Your Hoya Isn't Growing

Why Your Hoya Isn’t Growing

I stared at my Hoya carnosa for three months straight last winter. Not a single new leaf. Not even a hint of movement. Meanwhile, my friend’s Hoya was putting out vines like it was trying to escape her living room. I felt like a plant failure.

Here’s what I learned after digging through research papers, pestering my local nursery guy, and finally figuring out what I was doing wrong. If your Hoya looks alive but refuses to grow, one of these five problems is probably the culprit.

The danger of over-potting Hoyas

This was my big mistake. I bought a tiny Hoya pubicalyx cutting in a 2-inch pot and immediately moved it to a 6-inch pot because I thought I was being nice. Giving it room to grow, right? Wrong.

Hoyas actually hate having too much soil around their roots. In their natural habitat, many species grow as epiphytes, which means they cling to tree bark with minimal root space. They’re used to their roots drying out relatively fast. When you put a small Hoya in a large pot, the soil stays wet for too long. The roots just sit there in damp potting mix, and instead of growing new leaves, the plant focuses all its energy on trying not to rot.

I didn’t see any growth for months because my Hoya was stressed. The soil would stay moist for over a week after watering, and I noticed the bottom leaves started looking a bit yellow. That’s when I finally repotted it into a 4-inch pot, and within three weeks, I had two new leaves starting.

According to research from the University of Florida’s Environmental Horticulture Department, Hoyas prefer to be slightly rootbound. They actually grow better when their roots fill up most of the pot space. When you look at the bottom drainage holes and see roots poking through, that’s not a crisis. That’s often when Hoyas decide to put out their best growth.

If you recently repotted your Hoya into a much larger container, that could explain the growth halt. The fix is simple but annoying: you need to downsize. Choose a pot that’s only 1 to 2 inches larger than the root ball. Make sure it has drainage holes. Use a chunky, well-draining mix with lots of perlite or orchid bark so water moves through quickly.

After I fixed this with my pubicalyx, it went from doing nothing to putting out a new vine in about a month. Sometimes the solution really is just a smaller pot.

Mealybugs hiding in the vines

I almost missed these little demons on my Hoya linearis. The plant wasn’t dying, but it stopped growing completely in spring, which made no sense because that’s when Hoyas are supposed to wake up and start pushing out growth.

Mealybugs are sneaky on Hoyas because they hide in the leaf axils, which is that little pocket where the leaf meets the stem. On some Hoya varieties with thick, waxy leaves, you might not notice them until you have a full infestation. They look like tiny bits of white fluff or cotton. If you see any, you probably have more than you think.

These pests literally suck the sap out of your plant. They drain the nutrients and energy that should be going toward new growth. Your Hoya might look okay overall, but it won’t grow because it’s spending all its resources just trying to survive the attack.

I found mealybugs on my linearis when I was wiping down the leaves one day. There were maybe five visible bugs, but when I started really inspecting the vines with a magnifying glass, I found dozens hiding along the stems. No wonder the poor thing wasn’t growing.

The treatment took patience. I used a cotton swab dipped in rubbing alcohol to kill the visible bugs, then sprayed the whole plant with diluted neem oil once a week for a month. I also isolated it from my other plants because mealybugs love to travel. According to Penn State’s Department of Entomology, mealybugs reproduce quickly, and even a small population can seriously stress a plant and halt all growth.

Check your Hoya carefully if it’s not growing. Look in the leaf axils, along the stems, and even in the soil surface. If you spot any white fuzzy spots or a sticky residue on the leaves (that’s honeydew, which mealybugs excrete), you’ve found your problem. Treat it immediately. Once I cleared the infestation, my linearis started growing again within two weeks.

Above: A close up look at the symptoms.

Why new leaves fall off

This one drove me crazy with my Hoya kerrii. The plant would start pushing out a beautiful new leaf, I’d get all excited, and then three days later the leaf would turn yellow and drop off. It happened four times before I figured out what was going on.

New leaves falling off usually means inconsistent watering. Hoyas can handle some neglect when they’re dormant, but when they’re actively growing, they need reliable moisture. The key word is reliable, not constant. If you let the soil go completely dry for weeks, then suddenly drench it, then let it dry out again for a long time, the plant gets confused. It starts growing, then panics and aborts the new growth because it doesn’t trust that water will be available.

I was watering my kerrii maybe once every three weeks, and only when I remembered. Sometimes I’d feel guilty and water it twice in one week. My schedule was all over the place. Hoyas need a rhythm. During the growing season, which is roughly spring through early fall, most Hoyas want water when the top inch or two of soil is dry. For me, that ends up being about once a week in summer.

Research from Iowa State University Extension notes that inconsistent moisture is one of the main reasons Hoyas drop developing leaves and buds. The plant needs steady conditions to support new growth. If it can’t predict when the next drink is coming, it won’t waste energy on leaves that might die anyway.

I started checking my kerrii every few days by sticking my finger in the soil. When the top felt dry, I watered thoroughly until water ran out the drainage holes. I did this consistently for two months. The next time a new leaf started forming, it actually made it to full size. Now I have a whole string of successful leaves because I finally got the watering rhythm down.

If your Hoya keeps aborting new growth, pay attention to your watering schedule. Write it down if you need to. Find a pattern that works and stick with it.

Wrinkled leaves mean root trouble

When I see wrinkled or puckered leaves on a Hoya, my first thought used to be “it needs water.” Sometimes that’s true, but more often, wrinkled leaves mean the roots are damaged and can’t take up water even when it’s available.

My Hoya australis started looking wrinkly last fall. I watered it, and nothing changed. The leaves stayed soft and weird looking. I watered it again a few days later, thinking maybe I didn’t use enough water the first time. Still wrinkled. That’s when I realized something was wrong below the soil line.

I pulled it out of the pot, and sure enough, the roots were brown and mushy in spots. Root rot. This happens when the soil stays too wet for too long, usually because of poor drainage or overwatering. The roots suffocate, start to rot, and then they can’t absorb water anymore. The plant shows drought stress symptoms even though the soil is damp.

According to the University of Minnesota Extension, root rot is extremely common in Hoyas kept in standard potting soil without added drainage material. Regular potting mix holds too much moisture for these plants. You need something that drains fast, like a mix of potting soil, perlite, and orchid bark in roughly equal parts.

I had to cut away all the brown, mushy roots on my australis until I was left with just the healthy white ones. Then I repotted it in a much better soil mix and a smaller pot. I didn’t water it for almost a week to let the cuts heal. After that, I watered sparingly until I saw new root growth starting. It took about six weeks before the leaves plumped back up and the plant started growing again.

If your Hoya has wrinkled leaves and you know the soil is moist, don’t just keep watering. Check the roots. Healthy roots are white or light tan and firm. Rotted roots are brown, black, or gray and feel mushy or slimy. If you find rot, you need to act fast. Cut it away, repot in fresh well-draining mix, and adjust your watering habits.

A Hoya with damaged roots won’t grow new leaves. It’s too busy trying to survive.

Above: The tools you need to fix this.

Don’t cut the peduncles!

I almost made this mistake with my Hoya carnosa when it finished blooming for the first time. The flower stalk, called a peduncle, looked dead and brown after the flowers dropped off. I had my scissors in hand, ready to snip it off to tidy up the plant.

Thank goodness I googled it first. Hoyas bloom from the same peduncle year after year. If you cut it off, you’re removing the spot where next year’s flowers will grow. The plant will have to spend extra energy growing a new peduncle before it can bloom again. Some Hoyas take years to bloom in the first place, and cutting off the peduncles can set you back significantly.

This matters for growth because blooming takes a lot of energy. If your Hoya is spending energy regrowing peduncles that you keep cutting off, that’s energy not going toward new leaves and vines. According to the American Hoya Society, mature peduncles are essential for reliable blooming, and their removal is one reason some Hoyas never bloom in cultivation despite being old enough.

The peduncles look ugly, I’ll admit. They’re these little brown stubs sticking out from the vines. But leave them alone. On some of my Hoyas, I’ve seen the same peduncle produce flowers three years in a row. That’s efficient.

If your Hoya isn’t growing and you’ve been cutting off the peduncles, stop. Let the plant keep its flower stalks. You might notice it puts more energy into leaf growth once it’s not constantly replacing parts you’re removing. Plus, you’ll get more reliable blooms, which is always nice.

I haven’t personally bought some of the more finicky blooming Hoyas yet because my apartment doesn’t get enough light, but from what I’ve researched, this peduncle rule applies across the genus. Don’t cut them unless they’re completely dead and crispy all the way to the base, which is rare.

Growing Hoyas taught me that sometimes doing less is better than doing more. Smaller pots, consistent watering, leaving things alone. These plants don’t need us to fuss over them constantly. They just need us to get the basics right and then step back. My carnosa is finally putting out a long vine now that I’ve stopped overthinking everything. Turns out, the plant knew what it needed all along.

References

University of Florida Environmental Horticulture Department. “Hoya Production Guide.” IFAS Extension.

Penn State Department of Entomology. “Mealybugs.” Extension Publications.

Iowa State University Extension and Outreach. “Houseplant Care: Watering.”

University of Minnesota Extension. “Root Rot in Houseplants.”

American Hoya Society. “Hoya Culture and Care Guidelines.”