Yellow Veins

[Pachrian]

I found this on my Chariots of Fire this morning. What causes these yellow veins and what do I need to do?

[Darkhorse]

I have seen this before too.  some leaves just seem to yellow this way.  the whole leaf will probably turn yelloe.  ive noticed the yellowing leaf veins more often in certain cvs too, particularly silver memories.  not sure why.

[Pachrian]

This is so strange, I've never seen it before. I'm wondering if it has something to do with fertilizing. I switched to the Acid Blend fertilizer and just earlier this week saw 2 leaves on the same plant with a bit of fertilizer burn.

[Charlie]

I've seen this a few times but don't know what causes it. I've never seen it spread and plants with it recover on their own in my experience. It could be one of the rare mites, or temporary nutrient deficiency caused by a root problem, or who knows what. Please let me know if it does not go away and particularly if it spreads.

Charlie

[Pachrian]

I *think* it might have been caused by some kind of insect that somehow sucked the juice out of the new shoot. All these new leaves became very deformed and I ended up taking that opportunity to prune that branch back. So far I haven't seen any new leaves like his, knock on wood.

[Charlie]

That kind of thing happens sometimes. Often it remains a mystery but thankfully disappears on its own most of the time. They are worried right now about the Apple Brown Moth spreading outside of the downtown San Diego area. Apparently the little beastie can do a lot of damage to ornamental plants. I'm hoping to never see one up close and personal.

Charlie

[motherof4]

MY CREOLE LADY HAD A LITTLE BIT OF THAT YELLOW VEIN THING...I DONT KNOW WHAT IS WAS...ITS SEEMS TO BE LOOKING BETTER..LYNETTE

[Charlie]

Uli, looking back at your original photo I see a white speck on the leaf to the right of the small shoots. It's the right size and shape to be a whitefly - have you seen any tiny bright white colored flies buzzing around? They can cause yellow mottling as they suck the juices from the plant. If you see them it's a very good idea to treat early before they get established. They hate water blasting so your mite treatments would probably work to drive them away, too. If they do manage to get a hold they are fairly easy to get rid of with either Safari or Bayer Tree and Shrub drenched into the pot.

Charlie

[Pachrian]

Yes, I do get the occasional cluster of whiteflies in my yard...they love the cannas. I usually catch them when it's only a few flies, and I wipe them off with a soapy papertowel, that way they don't fly off and land somewhere else. Still, with the small yards we have here it's a battle I know I can't win, my neighbors all rely on their gardeners to take care of their yards once a week and they couldn't care less.

[blupit007]

Hi
 
  I just started getting some yellow leaves on a couple of my hib's.  All different patterns too.  Some all yellow, some spots, some veins.  And some with all 3 on the same plant.  I took some photos to show.  I went out with my 20X mag and looked them all over and over for the past 3 days and see nothing crawling.  Belle has some warty looking dark forms on her underside of the leaves though.  But other then that, everyone is super clean.  Some small spiders on them, but I leave them alone. 

  I feed with the HVH formula each Wednesday.  2 Wednesday's ago I added some seaweed plant food to the mixture.  Then a couple days later I added a 1/2 teaspoon of Epsom salts on top of the soil (which would be my second time doing so this summer).  Do you think one of these new additives might have done this?  I hope it is not bugs, as I just brought them all into my office in preparation for Hurricane Earl...
 
Yikes! ~ Kristen

[Charlie]

We have to keep in mind that not all yellowing of hibiscus leaves indicates a problem. Hibiscus naturally change their leaves. Leaves age, hibiscus drop them, and then new ones grow back in. Also, some problems are temporary and caused by changes in the climate. Hibiscus react to the change, and then return to normal quickly. This can happen following a heat wave that lasts a few days, or after the first chilly night of fall, or from things we never notice such as sun spot activity, insect attack that comes and goes quickly, and so forth.

If you do not find any insects with a magnifier that is a good sign that you don't have to be concerned. One of the best techniques for dealing with a few yellow leaves is to remove the leaves. Out of sight and out of mind. Of course if even more leaves turn yellow the next day or two you may want to re-examine the situation.

Some years ago an old time hibiscus grower made the comment that he had never seen a leaf yellowing problem that wasn't fixed with applications of either iron or epson salts. He was talking about the long term change in leaf color, not the kind of leaf yellowing that comes from spider mites or other pest attacks. I can't argue with that and always apply one or the other or both when leaves do not look nice and green.

Another consideration is the use of HVH Booster (potassium nitrate). Many minerals balance each other and in this case the potassium can upset the balance with magnesium. For that reason it is a good idea to apply either chelated magnesium or epson salts (magnesium sulfate) whenever using the Booster.

Charlie

[blupit007]

Thanks Charlie,  I think another factor that I didn't mention is that the temp dropped to the 60's at night 2 weeks ago, then last week it was about 90-100.  I forgot to water them and they got droopy and really dry.  Then I went with the hose and drowned them... oops.  no good huh?!