Heres picture 2, this is a pretty severe case

And one more with some new leaves

Once the leaves are burned like that, they will remain that way for the life of the leaf. It looks like either sunburn or fertilizer burn. the new leaves are looking good. As long as your new leaves are fine, I would ignore the old ones for now and keep an eye out for pests. If the plant was dry and it got fertilizer before rehydrating, you may have gotten the burn that way.

Any recommendation on feeding them ? Of the four plants only two are putting on new leaves.

This is not the growing season so fertilizing now is not really necessary. For Austin, I'd wait till mar/apr. Your plants look really good otherwise. Also, go easy on water as they tend to root rot easily during non growing season. When warm and hot, water away!

Once its time to fertilize, browse through this website:

www.hiddenvalleyhibiscus.com - they have some great fertilizers tailored to tropical hibiscus.

It's hard to say what caused the spoiled foliage pictured. It's not sunburn (photo-oxidation). It could be a result of under-watering, a high level of dissolved solids (salts) in the soil solution, depressed root function due to lack of O2 in the rootzone (soggy soil), or oedema due to one or more factors usually including a soggy soil + anything else that slows transpirational water loss including (partial) defoliation.

Never provide bloom booster fertilizers to Hibs in a container. The high levels of P in these fertilizers is very counterproductive to plant health and bloom quality/profusion. Fertilizers with the N:K ratio roughly equal or slightly favoring K and very low P in relation to N and K are best. Fertilizer ratios like 3:1:3, 2:1:2, 2:1:3 are very good. Remember that a fertilizer's RATIO is much more important than its NPK %s.

Since 3:1:2 ratios are excellent choices for a huge % of plants, You might try Foliage-Pro 9-3-6 fertilizer (a 3:1:2 ratio) and augment it's use with Pro-TeKt 0-0-3. Essentially, you'll end up with a 3:1:3 or 3:1:4 ratio with the several benefits offered by the silicon in opalene form contained in the Pro-TeKt. The 9-3-6 is an excellent fertilizer because it contains ALL the essential nutrients (most fertilizers do not) in a very favorable ratio, and it gets most of it's N from nitrate sources - not from urea. This fact helps keep plants full and compact.

Al

Update: So one of my plants didnt make it... it had mounted a strong comeback but suddenly wilted and died-- wilt disease due to some root fungus (my best guess) however the others are alive and thriving. I just got my first bloom and I even planted one of the strong ones outstide back in late January (here in austin it has been rainy and cold lows in the 30s for the past two weeks) Despite adverse weather my outdoor Hibiscus is still full of foliage and buds, perhaps it has gone dormant again till it warms up. The outdoor one is in a highly sheltered area near the house-- which I why I suspect it hasnt bit the dust yet. I will try to post some pictures soon! thanks for your help so far

One quick question: I have repotted several of my plants but the original soil that the plant comes in seems to get waterlogged much worse than the potting soil I put it in. Any one have any recommendations for removing the old soil from the root system? I am afraid of hurting the plant so I just left them alone but I worry that the root rot might strike my survivors if they are drowning in their original potting mix . I have cut back my watering substantially to combat this.

As a follow up I want to say that I used Al's 5-1-1 mix to pot in (or at least my best facsimilie) Al, do you have any recommendations for amending my terrible alkaline, calciferous soil here in Austin ?? I have read a lot about adjusting the pH but as far as addressing the drainage issues there is less information around. I want plant some fruit trees and was thinking of excavating a large swath and replacing/amending that area to help avoid the bathtub effect when only amending the soil near the new plant. My wife does not like the idea of a raised bed (my first thought to avoid soil trouble)

i am glad most of your plants made it! low 30's is about the limit for topical hib's - with lots of shelter. Mine go dormant right about the time i get to below 40 - they simply stop growing and resume in the spring. when i was more inland, i had two that would go completely dormant, lose all their leaves - the temps were more frequently closer to freezing. they don't like to freeze. Many of the specialty ones simply can't handle the low temps and will die off in the cold. make sure to frost protect the ones in the ground next winter! i don't have any of mine in the ground here - so not much help there.

Quick question. Back in January it was in the 70s for 2 weeks and my hibiscus put out 10 or so buds which remained through the freezing weather. Now that it is back in the 70s all of these buds dropped off. Is that a normal response to change in temperature or coming back out of dormancy. I know that pests can causes this to happen too but I havent seen any. Just wondering if I should be concerned about pests. I also notice that my outside hibiscus has developled nice thick tough foliage unlike the delicate foliage of my indoor plants.

if the buds froze - then its possible the freeze killed them off. though - be alert for pests as the weather warms up, the pests all start popping up too! and yes the leaves on indoor/outdoor plants change - they get smaller and harder to protect themselves from the weather. i also have a cutting that is showing much bigger leaves than the parent plant. the parent plant is older and has been through many freezes. good reminder to reboot my plants every so often.

I have had both hardy and tropical hibiscus throughout the years. My tropicals were potted and my hardys are planted in a flower bed. The tropical hibiscus should not be exposed to anything under 50 degrees. This is why I kept mine potted. I would cover them with a sheet on those nights that get cooler than 40. In regards to your pictures of the plants, I have had that issue and it was mostly connected to watering. Hibiscus are EXTREMELY picky about water. I finally purchased a thing from the hardware store that tests the level of moisture in the soil (under $30). It has a small diameter silver wand that you stick into the dirt. On the back of the package was a list of plants and what their ideal water level should be. This has helped me with not over or under watering them. They really do not like either extreme. Another thing you definitely will want to do is spray for aphids. They LOVE hibiscus leaves! Enjoy! Hibiscus are my favorite flowers.