If you’re growing hibiscus chances are it has a pest, in fact I’m guessing that’s why you’re here – because you’re looking for solutions to your spider mite infestation or aphid affliction. Hibiscus are tropical plants that grow in specific conditions and when you mess with those conditions it stresses the plant. A stressed plant is going to be prone to pests. Hibiscus that are grown in a greenhouse, then moved to a nursery and THEN moved into your home go through quite a lot in their journeys from fluctuating light and watering to the all important humidity and temperature drops.
The first indication that something might be wrong is likely going to be leaves that look like this. A stressed plant will first yellow then, drop leaves to preserve resources for roots. If you have yellow leaves on your plant the first thing I would do is look for pests. Aphids look like little green jelly blobs and they’ll cluster around flower buds and under leaves. Spider mites are a little trickier because you likely won’t see them until the infestation is pretty bad. I have most experience with spider mites so this is where I’ll focus.
On the leaf above you’ll see the tell tale damage of a spider mite problem. Pin prick holes on the leaves result from mites sucking the juice out of the leaf. You might also notice about halfway up the leaf a very tiny spider web stretching across from the left side, right over the leaf to the left. Enough mites presents enough of a problem that your hibiscus will drop those leaves. You’ll likely notice the effects of the damage and webbing long before you actually see any mites.
Spider mites, as troublesome are they are, are nothing to panic over. The focus should be on getting your plant healthy because a healthy plant is no place for pests.
5 Facts about Spider mites:
- Spider mites are a type of arachnid and not insects.
- Spider mites thrive in dry and dusty conditions.
- It only takes 3 days for a spider mite egg to hatch.
- Mites live up 4 weeks and can lay 20 eggs per day upon maturity.
- Spider mites are less than 1mm in size so they are very hard to see!
If you find your plant is infested with Spider mites the best thing to do is take it into the sink or shower and spray them off with water. Water is the enemy of mites. They can’t hold onto their plant homes and float away on the stream. They also can’t thrive in wet conditions. Considering the life cycle of this pest, it’s best to do this every 3 days for a week or two. If like me, you have a tree that can’t be easily showered off then maybe it’s time for a different approach.
In September I called in some troops. Ladybugs. While the ladybugs were not the ideal solution – they did work. I had ladybugs in my home from September through January and it gave my plant a fighting chance to get healthy. Ladybugs eat both the adult mites and the eggs. I combined this tactic with increasing our household humidity to 50% (remember mites like things dry) and daily misting with a spray bottle. In the photo above you can see tiny black dots on the leaf – those are mites.
Alternatively you can find predatory mites (Phytoseiulus persimilis) to go head to head with spider mites. The reason I opted for lady bugs is that predatory mites require a relative humidity of 60% or greater which is unadvised in a home setting.
Once the pest problem was addressed, I carried on with general hibiscus care and I am happy to report that my plant was healthy by spring and by summer covered in blooms!
A Note about Yellow Leaves
Yellowing leaves on a hibiscus plant with no sign of pests can happen for three reasons.
- Water. Follow your plants needs in respect to watering. Over watering does cause leaves to yellow and drop (under watering will cause leaves to wilt and crisp.) Your plant should be in a sandy, well draining soil mix. Mine is in half general potting mix, half cactus mix and has extra perlite added in as well to ensure water drains away and the roots aren’t sitting in wetness for too long. My hibiscus tree is also in a terracotta pot which is porous. When the leaves wilt I soak the soil through and for me, this happens about twice a week in summer and once a week in winter.
- Seasonality. Some Hibiscus growing in perfectly tropical conditions are green and covered in flowers year round but if you have a plant in your home it may act as a perennial. They can drop all of their foliage with the seasons if temperatures cool and light wanes.
- Stress. Moving a plant from outside to inside, temperature fluctuations and changes in lighting can all cause a plant to yellow and drop leaves. If you have recently changed something about your plants environment and then see yellow leaves, first check for pests, and then let your plant acclimate to it’s new conditions.
I hope this was helpful information and chances are, if you give your hibiscus plant the care it needs and time to acclimate to your home, it will get healthy and be less prone to pests. May I wish you years of beauty from yours!