Yellowish Hisbiscus Leaves

What's wrong with my hibiscus? The new leaves are dark green, and then they turn yellow. They still look healthy--just lose their green color. Do I need to add something to the soil?

I would give it some epsom salts and that should green it up. But you might wait for more of an expert to chime in.

I would add ironite, aka iron sulphate. Guaranteed not to burn the plant. It just makes nutrients already in the soil, more available to the plant. If magnesium deficiency is the problem, that's when I think you use Epsom salts which is magnesium sulphate. Maybe these products do the same thing, I dont know. Ive used ironite many times, never disappointed. I used Epsom salts on my brugmansia and almost lost it so Im kinda afraid of it but Im inexperienced at its use.

A little compost wouldn't hurt.

I agree with Frost...compost is always the safest answer and top dressing followed by a good watering is easy-do!

Im sure you already know that yellow leaves starting at the bottom and falling off is caused by over-watering. I understood that the whole plant looked yellow but thot I would mention this, too.

Thanks for the responses. My soil is very "amended." I've used lots of compost, and my beds are so full I think I would have to dig some dirt out before I could add anything else.

I'll look into the ironite.

And thanks for the overwatering tip. I don't think that's it, but I'll watch it. The leaves seem to all come in dark green and then turn yellow. No leaves have died. They all look healthy except for the color.

In my limited experience, Hibiscus really react to over watering. Another idea is that if the compost is not "finished" the composting will rob your plants of nitrogen and they will be yellow instead of green. I noticed that the veins of the leaves are still dark green. This suggests nitrogen deficiency but at this point I do not know what has caused it. Since you have really amended your bed, my money is on unfinished compost. There is not much you can do except add nitrogen until the material you added is finished rotting (composting).

This message was edited May 7, 2011 8:02 PM

sybram, I don't know if you have the awful clay soil we have over here in this part of Johnson County but... I have had a lot of problems with yellowing leaves or what I think is chlorosis. My plants and shrubs start out dark green and then eventually several have the yellowing problem. My new beds are elevated and really good amended soil that drains well but it sits on horribly dense red clay and when the roots reach the natural clay level, I think that's what causes the problem. The clay processes water very poorly. I've had good success with Hi Yield (brand) Liquid Iron with Micro Nutrients. I buy it at Lone Star Ag (used to be Mann Ag) in Cleburne. Another DG member recommended it to me.

I had a section of holly bushes that I thought were going to die with yellow leaves. I had accidentally over-watered them with my underground drip irrigation and they are in an area of my yard that I could not elevate the beds at much, so they have more contact with the clay. I used the Liquid Iron and it really brought them around.

The problem with ironite, at least as it used to be formulated, is that the iron sulphate is not readily available to the plant. The best product I've found is Sprint 330 - which I warn you is hideously expensive. It is the only product I've found in over 50 years of gardening that actually works on the problem and, trust me, I've used every one you can imagine: I use it on roses, gardenias, cleyera (which I wish had NEVER been planted), etc. The product is in powder form which you mix with water. I've seen plants respond within a week to ten days to it. But . . . . . . it is really expensive. I also put out chelated sulphur granules as backup about twice a year. This product breaks down very gradually, but helps me not have to use Sprint quite as often.

I also am using the new formulation of MicroLife Acid, but I truly rely on Sprint 330. Prepare yourself for sticker shock, but I've found it worthwhile enough that, although I shudder, I pay the price!
Leslie

iron sulphate is not used by the plant in my understanding. It's action is to un-chelate if I may coin a word, the minerals that are tied up by chelation in the soil. This makes the formerly chelated nutrients now available to the plant. The soil had the nutrients all along but in chelated form, the plant could not access them.

Some usefull info on Epsoms salts which I have used in the past. http://www.epsomsaltcouncil.org/garden_usage_tips.htm

Wow! So much for me to read up on. Thanks all.

I'll just add my 2 cents since we have so many Hibiscus and are used to their symptoms.

Hibiscus like acid......yellow leaves are usually a sign of lack of nitrogen......if you have acid food....you can use it, but we do natural.

We use home made compost mixed with coffee grounds to bump up the nitrogen. Cheap and very effective....just top dress and water in. Our compost also has peat moss mixed in it. We call it com-peat. So com-peat and some coffee grounds. Starbucks gives used coffee grounds away free if you don't drink it.

sybram, I can get you a 5-gallon bucket of coffee grounds any time you want it. We get more than we need from a friend's restaurant.

Thanks morganc. I have a little ph meter around here somewhere. I try to find it and check that soil.

I've always been afraid it didn't get enough water, but funny if I've been going too far the other way.

Dogs_N_Petunias, I would love the coffee grounds. Please g-mail me, and I'll pick them up ASAP.

Thanks, Jenna, for the coffee grounds. Now, how much to use? I used Osmocote on the hibiscus earlier (6 wks), so should I add anything to the coffee grounds now, or just use that now, and wait and see?

This message was edited May 14, 2011 8:25 AM

Sybil, I'm not experienced with hibiscus, so do not know how much coffee grounds to add. Hopefully, Morganc will give you some specifics on that.

We use gallons of the coffee grounds in our big compost bins, along with kitchen scraps, oak leaves, grass cuttings, llama and miniature donkey manure and some granulated agricultural molasses. Let that process for about 3 months and it is wonderful stuff.

When I made my new elevated flower beds about a year ago, I used sort of the lasagna method by putting down coffee grounds first right on the grass because I've been told it attracts the earth worms, didn't dig it up at all, then cardboard or newspaper, then a few more sprinkles of coffee grounds and then a mixture of compost and soil about 6 to 8 inches deep. The beds have done great. Very few places where the grass managed to come through and lots of big worms.

Almost all soil in Johnson County is alkaline and can benefit from acidic amendments, or so I've been told.

Glenna

As to coffee grounds.......we have our hibiscus in large pots so we can move them into a greenhouse over winter.....so I can only speak to what we do. With a large 12 inch or more pot.....I throw in about a half to 1 cup of coffee grounds, water it in and wait a few days. Then throw in more if necessary.

I am told by The Natural Gardener folks that Cottonseed Meal is also used for greening things up. All natural so no burning. We have some but haven't used it like the coffee grounds yet.

Whatever you use natural or otherwise if you out too much Nitrogen on a plant it will burn it ,I myself would try the ironite first with it you can see results almost immediatly al it does is lower the Ph value Plain old sulphur will also do that

Well, I got some Ironite, but I had already applied some coffee grounds that Glenna so graciously gave me. I also have sulpher. The problem is I don't know how long to wait before adding more coffee grounds, or do I abandon the cg and just go with Ironite...............or sulpher...................and if so (or not) how much do I add. I haven't read the Ironite pkg directions, so it may say on there.

Advise please on my next move. BTW, I used a big scoop of coffee grounds, but of course you don't know how much hibiscus. Hmmmmmm...........I'd say there's about a five foot diameter circle of hibiscus.

I think I may detect a little greening. It's been a week or so since I added them with two waterings.

The used coffee grounds have never hurt anything I have put them on. Sometimes I even poured used cold coffee on the plants and they thrived. We check our plants daily, so if there is ever a problem we are right on it.

I used to pour my left over cokes from the car on my plants. Never hurt anything and they seemed to like it.

Wow! I love you guys and the wealth of information you share. Thanks all.

Great idea, Glenna. I have a wall date calendar in my mud room for that purpose. Now, if I can just get better at jotting stuff down, I'll have it made.

I use the calender on my puter as a journal for my garden and since I check on Dave's every day I do remember to do the journal

Oh, to be so consistent, Grits. Maybe someday...................

Hey now I didn't say I was consistant only during planting/harvest seasons I enter the temps as a rule first thing every morning and any other weather conditions that may be revalent such as T&L and rainfall amounts ..this lets me look back as far back as the age of this puter (March 2006),..today I was fretting about being so far off the pace this year then looked back to last year and am within one week on most plants and no more than 2 weeks on others ,just unseasonally cool this year...