Opinions please...

G'day all!

New to gardening and growing Hibiscus. I have two President Hibiscus trees planted in my garden, (about 2 weeks now) and today, I was looking at the flowers and I swore I saw a small greenish bug sitting on one of the flowers. It jumped or flew away quickly so I didn't get a good look, but it was smaller than a grain of risotto. Further inspection of the leaves revealed holes in numerous leaves and some white film on the underneath side of many leaves.

I am pretty sure it was an Aphid that I saw, and from what I can tell, the holes in the leaf (macro photo posted below ) match those done by the Aphid.

Can someone please confirm this and tell me what is the best and safest was to rid my trees of them?

Cheers,

Mac
LBK, FL
Zone 9b

I'm not sure you have aphids...first of all there's never just one, you'd see others hanging out (most likely on tender new growth or on flower buds, not typically on a tough old leaf like the one in your picture). They also don't tend to move much, they find a spot and sit there and suck on plant juices. And I've never had them make holes in leaves--they suck the juices out of them but don't chew holes in them. The white film on the underside of the leaves also is not a symptom that they would typically cause. So the first step is to figure out what you have so that you know how to kill it. Can you post a pic showing the white film on the underside of the leaves? That may help narrow it down.

G'day ecrane3! (Wish I knew how to address you a little more cordially, considering you graciously answer all of my posts for help - haha).

As requested, here is a photo of the bottom of a leaf showing the whitish film. I got to thinking after my post, could the white film be dried neem oil? I sprayed the plants about a week ago for posterity sake and for leaf shine, so maybe the film is old neem that didn't drip off? I haven't tried to wipe it off yet, so I don't know if it comes off easily. I will check today.

I think the tiny green bug I saw yesterday must have JUST landed on the plant. It was sitting on the flower itself and not on a leaf, and my understanding is, Aphids hang out on leaves not the flowers. I also have seen a few ants crawling on the flowers which may mean have been around at some point.

Here's the underbelly of the leaf. Let me know what ya think. I haven't seen anything on the new growth areas or flower buds before they open.

Do you have any Hibiscus in your garden? Do you know if the 1cup of white vinegar to 1 gallon of water poured on the soil at the base of the tree helps the yellowing of leaves? (Read this online and the theory is it boosts the acidity of the plant and thus reduces yellowing of the leaves).

Whatcha think?

Thanks for being my personal sounding board for my rookie gardening! Much appreciated! :)

Cheers!

Mac

This is another leaf I found this morning.

And another...

New photo posted at the NBJ thread, BTW.

Mac

Here's a better shot of the leaf posted above. Something has really had it's way with this one... bloody hell!

Any reason for the blooms to fall off leaving the stems sticking up like this? It's almost as if somethng like a bird is marauding the buds and snapping them off. I do find many empty green parts of the blooms on the gound, but there are no buds in them. The stems look healthy so I am not sure what's going on here.

Here are the empty bud "shells" I find all over the ground.

What's your grasshopper population like? I've see grasshoppers eat the flower right out of the bud before it even blooms.

Anne

I think Anne may be right. It Looks like a muncher to me.

I live out in the country and there's just nothing to stop them. Although I do try to put out bird feeders to entice the birds to the yard. I think that helps. I know that there is something called Nolo bait but where I live it doesn't do any good.

AuntAnne & Pizonne: Perhaps you are on to something!! When I mow or water my lawn, I do occasionally have them fly up from the grass at me and fly away. (They are the long-distance flying ones - I think called Bird Grasshoppers). I see maybe one actively flying per day, BUT my house IS flanked on both sides and to the rear by heavily wooded, undeveloped lots, (see photo), so I am certain there are many more. I have never SEEN one on my Hibs, but that doesn't mean it isn't happening.

Any advice? Should I be trying to attract bats now? haha

Thanks AuntAnne!

I fear I am like you and where I live which is smack in the middle of a swampy, jungle-like area, so I don't think the NoLo product will prove effective for me either.

Are there any specific birds I should be trying to attract that fancy the bird grasshoppers? Their bodies are about two inches long, with a wing span of 4" here.

Any recommendations on feeder types or bird seed mixes?

Thanks a million!

Mac

This message was edited Apr 23, 2009 12:44 PM

I haven't ever planted my hibs in the ground, though in my zone I could. They seemed to like the red ones best so the best that I could do was keep the pots as close to the house as possible, ie away from my garden and lawn. So I really don't know what to advise on the ones in the ground. Hopefully someone will have advise to offer.

Anne

Like the red ones best, huh? Well, this must look like a Filet Mignon to the little buggers, then!

Thanks for the insight thus far Anne. Maybe someone else will have a suggestion. What birds should I be trying to attract? Anything specific?

Cheers,

Mac

Hey Mac, I think it looks like grasshopper holes too. Grrr, I hate those little buggers, and if I can catch them with my pruners, their sad hibiscus-eating lives are cut short (lol).

I wonder if the Bayer 4 in 1 powder would discourage them. Or neem one something like that. What do grasshoppers NOT like that wouldn't hurt the hibs, cayenne or something like it? Perhaps there's some companion plant that discourages them. I've heard that marigolds discourage snails maybe there's something comparable for hoppers.

Anne

You know, I was recently reading about a natural product to cut down on the grasshoppers - those suckers are just almost impossible to get rid of, at least here in So Cal. I'll look it up and repost :-)

There's an article on Dave's that says that something called Robber Flies....I think that was the name, eat grasshoppers.

G'day all!

Hmmm.... no, no Robbers for me. We had them in Australia and they are wicked. They kill everything from bees to dragonflies, ladybugs to cellar spiders. They are vicious killers. They inject their prey with a neurotoxic venom to paralyse the prey, then enzymes in the venom turn the bug into bug soup rather quickly and the resulting liquified slime is then consumed by the robber fly drinking it. Truly a wicked predator. Problem is, they multiply rapidly and then you have too many and then swarms of them can occur. No thanks on the Robber Flies, but a GREAT WAY to kill grasshoppers for sure!

I think I am going to try to attract some birds with a birdbath and feeders. Anyone know where I can find an attractive, low-profile birdbath? Something more decorative than the old cement-casted ones of yesteryear?

Thanks again, everyone! Appreciate the tips and advice.

Cheers,

Mac

I was out watering when I got to thinking. The grasshoppers are the reason I can't have gladiolas or hollyhocks for that reason. I still have a few gladiolas that come up but as soon as they put up the stalk for the bloom the grasshoppers chew through the base and there goes the bloom. It seems to be worse the hotter and dryer it is. So far we're having a wet cool spring.

A

G'day Anne! Thanks for that tidbit of info Anne. I was just about to plant two rows of Glads across the rear of my home, so now I am not sure if I will if they attract grasshoppers or will not survive longer enough to bloom.

Bloody hell... I am running out of ideas to colour up my lawn. Seems everything I want to plant is prime eating for grasshoppers.

I have recently planted some Aztec Gold sunflowers. They are about an inch tall.

Do you know if the hoppers are going to destroy these as well?

Thanks Anne.

Happy Saturday! :)

Mac

Mac, I can't say that your glads would be eaten. I don't know about your climate there but we get very hot and dry here. That's when the hoppers are the worst here, and they move in on the plants. I have irises and daylilies without problem. But you never know what works until you try it.

me

Okay... I will give them a try then.

It's Florida, so it can and does get hot, (80-90 degrees recently), AND it's also very dry currently as we are experiencing a severe drought. Come June however, it will be officially hurricane season and of course it will rain practically every afternoon to some degree, whether there is an active storm or not.

Because of this, I may wait until the middle of May to plant the Glads. How long do they take to come up? I have a couple of bags of a "25 corms, Hybrid Mix" bag. The planting time says Feb/Mar for my area, but I am not sure why this makes a difference in Florida. The conditions are pretty much the same in Feb/Mar as they will be in May or June, with the exception of the 10-15 degree increase in heat. These will only get partial, morning sun (approx. 4 hours) and I was waiting as long as I could to plant them so they could be watered by the supplemental rains.
Hope I am not too late.

Regarding my Hibs, I have recently experienced yellowing of the leaves as well as the hungry, hungry grasshopper issue, so I used the vinegar/water technique to increase the acidity of my soil. This has helped reduce the yellowing of the leaves, but the blooms have slowed down considerably and they aren't as pretty when they do bloom. Not sure the trade off is worth it.

Anyway, thank you for your input along the way. :)

Cheers love,

Mac

If your hibiscus are in containers I'd check your pH before you go trying to adjust it--I'm not convinced it's a pH issue, that doesn't tend to be as much of a problem with container mix. And if your pH is too high, I don't know that I'd use vinegar to adjust it, you'd probably be better off with sulfur or something like that instead.

You might try fertilizing them and see if that helps, look for a fertilizer that has iron in it since iron deficiency can cause leaves to be yellowish with green veins. Or if the leaves are turning completely yellow (no green veins), that can be a sign of inconsistent watering. Whenever the weather is hot I tend to have that happen to mine a fair amount because they get a little too dry between waterings, and alternating between really dry and then really wet makes them unhappy. The trick is to keep the moisture level more consistent.

Thanks Ecrane3! The hibiscus trees are planted in the ground outdoors. The 1 cup of vinegar to 1 gallon of water treatment was a trick I read about online and it has proven to be quite effective, but I also haven't watered them everyday either. I am so paranoid now about over-watering from the NBJ episode I can't find a happy medium now, I guess! Haha. The leaves were turning completely yellow, not the yellow with green veins look, consistent with iron deficiency but thanks again for the reminder. I will also watch for that.

I have well water with a noticeable sulfur odour. If I water my plants with it could the soil become too acidic or is it a different composition of sulfur?

Are your hibs in pots or do you have yours in the ground? Are they trees or bushes?

That's exactly why I would check your soil pH before you add any vinegar to it, I have a feeling your soil pH is probably already a bit on the acid side. The water you use to water is part of what contributes to your soil pH, but unless you've been having a lot of trouble with your plants it probably just keeps your soil a bit on the acid side but not excessively so. But I would not recommend adding additional acidifying agents like vinegar unless you've done a pH test and know that you need it. Also if the leaves were completely yellow with no green veins, then it is absolutely not a pH issue, it's probably a watering thing as I mentioned, or they'll do that if they're recently transplanted as well.

Mine are all in containers because they don't like our winters so I need to be able to put them in the greenhouse--inconsistent watering which leads to the yellow leaves is definitely more of a problem in containers than in the ground, but if your soil is sandy it could happen to plants in the ground too.

Mac
Have you checked out the thread entitled "The recipe"?

Anne

I think your idea about adding water to attract birds is spot on. There are many low profile birdbaths out there and right now the water is more important than food for the birds. I use decorative pottery/ceramic pie plates set among the plants. I also have a shallow regular birdbath. Shallow seems to be the key as the birds (around here anyway) prefer shallow water. Do you have Wild Birds Unlimited store near you? They always have a wonderful selection of interesting bird baths. Be sure to use mosquito dunks or drops to prevent skeeters.

And, I second ecranes suggestion to never try and adjust the pH without a soil test.

Good luck.
alice

ecrane do they do as well in pots as in the ground? How big a pot do you use? I've just gotten into the tropical hibiscus and have all three in the ground but there are a few others I would like to purchase, I just don't have flower bed space to put them in so would have to go into a pot.

In my garden they do far better in pots because my winters are a bit too cold for them to stay outdoors, and most of my garden is in full blazing sun and doesn't get watered very much so they'd be unhappy in the summer too. If you can give them appropriate conditions in the ground, as with anything I expect they'd probably be happier there. But many people grow them in pots so there's definitely no reason you can't do fine in containers. As far as pot size, as with anything you will need to start it off in a pot that's the appropriate size for the plant you have, and pot it up as it gets bigger.

Are they pretty much water hogs?

G'day Anne!!

No I haven't read "The Recipe". I am new to DG and am learning how to get around still.

Can you send me a link?

Thanks!

Mac

They're do need a decent amount of water although I wouldn't consider them a huge water hog. In my case I've purposely planted most of my garden beds with plants that have very low water needs so I don't water the beds frequently enough to grow things with "normal" water requirements.

I think it is our hot nights on the east coast Liz, our plants grow/metabolize 24/7 in the warm weather whereas yours get to rest at night.

Mine are all in pots and during the hottest part of the summer I have to water every day and they prefer twice during July. Mac, I'm not very computer literate. Can someone else do the link to the "recipe" thread?

Anne

It's not too hard to paste links--if you know where the thread is go into it, and use your mouse to highlight all the text that's up in the address bar of your browser (it'll say http://davesgarden.com with some other stuff after that) Hit control-C to copy it, then come back here and hit control-V to paste it into a reply here. If I had any idea where the thread was I'd do the link for you but I am not familiar with it.

Here is the link to "The Recipe" I have been using this on my brugs and hibiscus and after about a week or so of spraying every other day, everything greened up beautifully from sad pale green. I do not use any fish emulsion.. did in the first batch I made and can't stand the smell!

http://davesgarden.com/community/forums/t/956114/

I noticed some variations of the recipe include bloom booster fertilizer--for hibiscus you do not want to add that, they don't like a lot of phosphorus the way some other plants do so you shouldn't use bloom booster type fertilizers on them since they are too high in phosphorus.