Did the bud not drop down to the floor? It is very common to have bud drop for a plethora of stress related reasons like temperature swings, water issues (too much or too little) insect pests, etc

location.. potted.. etc... plus a pic of the whole plant ...

you havent given us many facts to work with ...

has anything happened.. weatherwise.. since the flower buds formed a few weeks ago ... vacation .. drought.. etc ...

ken

>Did the bud not drop down to the floor?<

No Luis, the bud is still on the plant but the green casing around the bud is empty. Sounds weird, I know, but they form the shape of the bud but nothing's inside. I can see before they even open up that they're totally empty. ("Full" buds look like they're bursting to get out of the green casing.) The green casing opens up to reveal nothing but empty space, then they yellow and fall off the plant. At least 50% of my buds do this. Very rarely does a full bud drop off.

>location.. potted.. etc... plus a pic of the whole plant ...<

Ken, I'm in Zone 9, Sacramento region, temps in the upper 90s to low 100s. The hibiscus is planted in a large pot. I typically water it every other day -- every day during the hottest temps. I started off the season giving it some Osmocote, then an occasional drink of fish emulsion and molasses.

Edit: Let me add that the leaves look very healthy -- a nice glossy green. The plant itself doesn't seem to be ailing, though I can't say it's grown terribly vigorously since we planted it in May.

Here's another shot of an "empty" bud.

Edit: Oh, and let me add that this is not the first season this has happened. Seems to happen every year, I'm just finally getting around to trying to remedy it.

I Googled this last night, and the prevailing wisdom, which was limited, was that it probably has something to do with too much/not enough water, fertilizer, or sun, as Ken said. I would stop automatically watering every day and start checking if it needs water by pushing your finger down into the pot to see how wet it is, and only watering if it's dry - hibiscus likes moist, not wet.

I would also consider repotting it, or at least checking to see how rootbound it is; the pot is nice and deep, but it's not very wide, and the roots might be circling around.

This whole thing is complicated by the fact that the Hibiscus family is big, and includes tropical, hardy, and shrubby plants, right up to Rose of Sharon, and the internet advice on one does not apply to the others.

>the prevailing wisdom, which was limited, was that it probably has something to do with too much/not enough water, fertilizer, or sun,<

I appreciate the response, Lisanti.

The question remains, which is the likely culprit? Too much water, fertilizer, or sun, or not enough water, fertilizer or sun? These empty blossoms seem to be an uncommon occurrence, judging by the dearth of info I can find online.

Check this out:

https://gardening.yardener.com/questions/Hibiscus-Buds-Turn-Yellow-And-Empty-Inside

Thanks for the link, Luis. It's odd, my Hibiscus is one of the few things in my garden that looks totally happy with no insect damage. :/

I happen to have a spray containing Spinosad. I applied it early this morning, and will keep my fingers crossed.

I appreciate your input.

That really looks like what is left when the opened flower falls off and not an empty bud.

Thanks for the suggestion, but no, that's not the case. I don't get many blooms on this plant -- one every couple of days. So when one is on the way, I watch the bud with great anticipation. But so often, they're just plain empty.

I sprayed recently with a spray containing spinosad. Didn't seem to help much. Still getting empty buds. :(

I have the exact same problem- empty buds. Mine is in the garden, it doesn’t get a lot of sun however. I am in a sub tropical zone in QLD Aus. I get the odd flower but mostly empty ones. It is in an established garden, so it’s been here for years. I do prune it, fertilise.

It's is the most well-known reason we see for hibiscus buds tumbling off. Conflicting watering. At the point when the plant experiences times of remaining sodden, at that point drying out for some time, at that point remaining damp, at that point drying out once more, the hibiscus buds may drop off. To forestall this, attempt to keep your plants uniformly watered.

It's not a case of falling off. It's a case of having empty "shells" for lack of a better word. You get what looks like a green flower bud, but there's nothing inside. It's hollow.

I've had better luck in recent weeks. I ditched my moisture meter and now rely on sticking my finger in the soil to see when I need to water. I also fertilize every other week. I recently got a few days in a row with three blooms opening up -- a new record for me! :)

We live in central PA and have a potted hibiscus that is very healthy. We too get many "empty" pods throughout the year which was a little disconcerting for us. The most blooms we've had at any one time is three or four. Have yet to get a definitive answer as to why there are empty pods. Most, like here, figure that we're doing something wrong. Will let you know if we ever figure it out but for now it remains a mystery! You are not alone! Haha

Yes, like you, the most we've ever gotten at one time on our Hibiscus plant is three flowers, which we managed to do twice last week. It's been a lovely autumn here in Northern California this year, and the flowers are putting on a nice show as the season winds down, particularly the dahlias.

I used to have the same problem. I fixed the issue by alternating feedings with adding a 5-50-4 blooming and rooting fertilizer. So if I fertilize week one with a organic fish emulsion, the second week I hit it with a high phosphorus fert. Now here’s the key, every other month instead of the week one week two fert rotation, I hit it with two straight weeks of Clearex. This “flushes” the plant - actually naturalizes the heavy chemicals so the plant won’t develop root lock up.

try that and your troubles will be over - ie. as long as you’re not drowning the plant. Moist not wet. Steady temps - around 70 and 12-16 hours of a 300 wt or more equal LED

50% phosphorus is off the scale.

No idea what the basis for this statement is:

naturalizes the heavy chemicals so the plant won’t develop root lock up

I appreciate the input here. Late in the season, I started applying Fox Farms' Tiger Bloom fertilizer, which is 2-8-4, and my hibiscus did seem happier. The empty buds seemed less frequent, if not altogether gone. Seemed to work well for my dahlias as well.

Clearex, huh? I could see how this could come in handy to eliminate salt buildup with container plants.

I'm grateful for the suggestions.

What do you mean off the scale ???? phosphorus is vital for root growth and especially for the bud development of flowering plants. I’m confused why you would say off the scale.?... I do this for a living. if you want a lot of blooms , you best know how to push a plant . As far as the clearex, by fertilizing on a regular steady basis , if you dont neutralize or flush the salt build up / ph changes produced by steady fertilization, the plants roots will develop nutrient lockout. (root lockup). the roots cannot absorb what is given.... I see this ph problem in a lot of plants where people do not flush their plants and do not pay attention to their growing mediums ph

If you want more blooms be a better gardener and not just focus on water, window light and fertilizing once every 2 months

Each increment (point) of pH is thousands of times higher or lower than the next one. So I'm not sure how periodically applying a chemical product is going to change the pH significantly, every time it is applied. Or how being able to produce that much of a change so quickly would be desirable.

And of course if fertilizer is not over applied in the first place then there is no need to attempt to correct the effects of these applications later.