Hibiscus is turning yellow

[Shu'ayb]

I have a hibiscus tree I got a few months back because it was grown in another nursery and they used osmocote. The nebari was half an inch out of the pot! After I reported it in straight perlite because it had a 10 inch taproot to keep it up, for 2 months it did amazing. Blooms almost daily, dark shiny foliage. Then I had to move closer to the ocean. Same city but the noticable difference is the fog. It's getting full sun. Today is the day I was going to fertilize but I'll wait till I get a reply.

 

[Vance Wood]

They like tons of Iron.

 

[Shu'ayb]

Should I get some blood meal dissolved into water or use ironite in the same fashion? Also I know it's fall just in my city they all do great year-round

 

[leatherback]

They like tons of Iron.

Thx, did not know this.

 

[sorce]

Welcome to Crazy!

Sorce

 

[shinmai]

I fertilize most of my deciduous trees with fish goop, one tbsp. per gallon, plus a tbsp. of Grow More 10% iron chelate powder, every other week during the not-winter season [we only have two seasons in Wisconsin]. The hibiscus in particular just love that combination.
A little magnesium once in a while is good, too. When I feed my roses, I use equal parts of Bayer Rose food and Epsom salts, which is magnesium sulfate. The difference in the foliage is amazing. You could get the same benefit with the hibiscus by sprinkling a teaspoon or two on the surface once a month, and letting it dissolve its way in when you water.

 

[leatherback]

I fertilize most of my deciduous trees with fish goop, one tbsp. per gallon, plus a tbsp. of Grow More 10% iron chelate powder, every other week during the not-winter season [we only have two seasons in Wisconsin]. The hibiscus in particular just love that combination.
A little magnesium once in a while is good, too. When I feed my roses, I use equal parts of Bayer Rose food and Epsom salts, which is magnesium sulfate. The difference in the foliage is amazing. You could get the same benefit with the hibiscus by sprinkling a teaspoon or two on the surface once a month, and letting it dissolve its way in when you water.

good to know. I have been too gentle. I did see some deficiencies but thought it was due to being dug recently.

 

[Bonsai Nut]

Yo! San Diego in the house!

(1) Welcome to the site!
(2) Have you tested your (guaranteed to be) crappy city water? Given the fact that your hibiscus is depending on your irrigation... it is sad what San Diego has to offer. Check your water quality report from your water utility - they are required to provide it via Cal law. Specifically, check the pH and see how high it is. 7 is neutral. Hibiscus like acidic water (less than 7). I would not be surprised if your water is 8.0 or 8.5. No bueno.
(3) The key to hibiscus is (a) sun (b) humidity (c) soft water. For what it's worth, they have weak roots and don't like to be messed with, but once established they can be quite strong in SoCal. The issue is going to be humidity and water. A hibiscus that is green and happy in full tropical sun in Hawaii is going to sulk, if not outright burn up, in SoCal desert winds. So I found (after 20 years of experimenting) that they do best in landscape where you can give them full sun, but protect them from any wind. Additionally, use acidic soil fertilizer - not so much because they require it, but because you need to counteract the impact of your alkaline water.

Loving the fact I see a lot of pumice. Consider mixing it with some rough cut peat moss. Yeah I know, you have been told to go 100% inorganic, but in SoCal peat will bring you acidity and humidity. If you are mostly pumice, your soil won't clog easily.

 

[Shu'ayb]

So should I just add 30%vinegar to the water to be on the safe side. And I got alaskan morebloom, which is basically fish goo and potash. Thanks for the advice!

 

[JPfagus]

So should I just add 30%vinegar to the water to be on the safe side. And I got alaskan morebloom, which is basically fish goo and potash. Thanks for the advice!

Why would you add vinegar to the water? Not a good idea.
Also 100% perlite is probably not doing your hibiscus any favors.

 

[Shu'ayb]

Why would you add vinegar to the water? Not a good idea.
Also 100% perlite is probably not doing your hibiscus any favors.

I was thinking of repotting it in December. Why would it be a bad idea? I know the holding power blows but the roots of my other plants enjoy it greatly. I have a dieffenbachia that was in straight perlite and did amazing until I moved by bus across san Diego and the shock took all but the main leaves. I understand that the whc is less with straight perlite. But the high porosity of the media allows the nebari to grow more thick and when I first repotted it a month ago it bloomed so much the following week I was shocked. The leaves were like my alocasia almost. Then I moved all the trees with various friends who drive either insane or smooth as heck. The only plant doing this is this one . The other is budding just splitting red should get one last splash of color before it gets too cold. In Linda Vista it is so wet at night if you wipe your shirt with a dry hand it will come back wet. With strangers perlite after a few inches it is like a cantelope. So I don't water more than I have to. I fertilize with miracle grow all purpose every other week. And alaskan morebloom every third week. My camelia is budding so I guess late fall is here. I'm thinking to fertilize two more times and then stop for winter. All insight is an honor from people who understand plants so we'll.