What is the best fertilizer for tropical hibiscus planted?

Hello everyone and a happy spring to all of you. I took the plunge and purchased a beautiful tropical hibiscus with amazing blooms and buds. Now my challenge is to keep it blooming during the summer. I have no trouble keeping it alive, but I stuggle with keeping it blooming, or should I say I've had trouble in past years. So, I come to you asking for help.

Carolyn

There are some special fertilizers just for Hibiscus, hopefully someone who's tried those will come along and give some perspective on whether they actually work better than other ferts. My experience has been that they'll bloom fine using the regular fertilizer that I use on all my other containers (two years ago it was Miracle Gro, last year it was Ironite, this year we'll see!) I also used Messenger last year and that may have helped, but I didn't have it the year before and still had blooms. I'm pretty lazy about the fertilizer and don't do it nearly as often as you're supposed to and mine still bloomed fine, so if you're having trouble getting yours to bloom it may be something else besides fertilizer (either that or I've just gotten lucky!).

Thank you for your reply. I usually use Super Bloom when I use non-organic fertilizer. I'll give it a go. I really love the flowers on this plant!

Carolyn

Doesn't Super Bloom have a high middle number? It was my understanding that hibiscus, unlike other blooming plants, do better with less phosphorous.

That said, I used to work for a large fern and tropical wholesaler, 8 acres under glass. The owner used whatever fertilizer was cheapest at the time; the blend never mattered to him. The plants always did well so I guess............whatever.

Thank you for your reply from SC. I just know if we all put our heads together we'll get just the right fertilizer for this plant. My plant in the past grew, but failed to bloom, so I'm guessing it wasn't the right fertilizer for blooming.

Carolyn

I use the "special" fertilizer from Hidden Valley Hibiscus and have had excellent results - they also have a new addition called "bloom booster" that you use with the fertilizer. I just started using the combo, so I don't know how it will compare yet.

I know that David from A Touch of the Tropics sells a "special" mix as well.

karen

Hi Carolyn

Hibiscus don't want a high phosphorus fertilizer. If you can get something in the 2-1-2 ratio. We offer a 20-10-20 fert that is excellent with all of the mircro nutrients your hibiscus need but you can always use a balanced fert as well like 10-10-10 or something similar. High phosphorus ferts like Super Bloom or Bloom busters do not make more flowers and in the long run they can be harmful to your plants.

Hope this helps.

David

Thank you Karen and Dave for your replies. I love the "A touch of the Tropics" site. I think I'm good to go now.

Carolyn

I think any good commercial fertilizer works well, if the ph of the soil makes the nutrients available to the plant. Ph has been more of a factor in my experience than the actual brand or type (organic/inorganic, numbers, etc.). I have to test my soil every year, because the only water available (well water) has a high ph, and a high salt content. My house plants fare great, because I water them from my rain barrels. Never have to "adjust" their ph. Can't reasonably do that with the greenhouse/grounds, so when I notice a "general decline", I send off some soil samples. They inevitably come back in the 8.0 and up category, and I whip out the gypsum and iron sulphate, and in a month or two, things are growing normally again. BTW, the "Low Country" where I live is generally noted as having "acid" soil. And generally, they're right. Just not in my case. So it helps to check...

Thank you StonoRiver for your reply. So what's your take on the pH of the soil if we plant these beauties in potting soil? Isn't MiracleGro soil usually neutral? Hum, got me thinking now>>>>

Carolyn

Stono, those of us along the coast are gardening on soil formed over millions of years of crushed oyster shells. We have a high pH down here too. Gypsum is often hard to come by around here; where do you get yours?

Carolyn, I can't speak for Miracle Gro soil but I know if I root hydrangeas in ProMix they bloom bright Pink so it must be a neutral to higher pH.

Hello Stono and all

Stono I completely agree with you about ph because without a the correct ph (for hibiscus this would be between 5.5-7) your plants may have nutrients unavailable to them. For those of us in pots though your typical potting mix has the proper ph for most plants so nuitrients would be there. Different plants have different requirements. Hibiscus want a high nitrogen, low phosphorus, high potassium food or at the least a balanced fert. Don't disregard the minor elements though. Things like magnesium, iron, zinc etc that will keep your plants at their best. Many commercial brands of fertilizer don't include these so you have to buy chelated iron etc. By the way, for hibs one tablespoon of epsom salts once a month will keep your hibs nice and green...magnesium! Make sure you buy a high quality fert that includes minor elements.

Stono in general I agree that feeding your plant something is better than nothing but it's worth the effort to find the right food for the right plant.

David

^~^~^~^~^~^ running right out to put epsom salts on my hibiscus babies......

Ardesia---I got my gypsum at Cross Seed a couple of years ago. I had to fight to get it, so I bought 150 lbs. of it, and I'm now running low. I think Hyam's may be willing to special order it if they don't carry it. Cross has gotten terribly unreliable lately.
David---couldn't agree more with you that meeting an individual plants nutrient requirements is always the best way to go, providing they can get to those nutrients. My point was simply to make sure the ph of your soil ALLOWS the plant to use those nutrients---after that, I'm not so sure it matters which brand/type of fertilizer you use matters. I've had excellent luck just using a common 10-10-10 (WITH micronutrients). What the plants didn't need, they ignored. There seems to be enough of what they really DO need in the 10-10-10 formulation to cover their needs. But only if the ph allows them full access to it. I do have to apply it monthly, though. I'm experimenting this year with a 14-14-14 slow release with a (supposedly) 6-8 month release cycle to see if that can cut out the monthly walk-around-throw-fertilizer cycle. Ya just gotta keep trying...

Hi Stono

Yeah, we're on the same page exactly and really was clarifying for those who don't know. One word on slow release ferts by the way, many of them are temp sensitive and in hotter weather they release lots of fert quickly and in cooler climates they release less fert. So the amount of time they are good for is dependent on your climate. This is really true in the dry heat of the desert like Az. where the pells will only last perhaps half the expected time. I like to use time release in with my mix as an additive. Seems to speed things along and it's the best fertilizer for those who don't have the time for water soluble or can't remember to do it.

David

Well Stono, we know your fertilizer won't last very long around here don't we. LOL

I generally count on about 8 weeks for a timed release that says it lasts for 4 months. Another thing to consider is that *occasionally* we have torrential rains (not that I've seen much of that lately). I suspect the unusually heavy rains will also deplete the timed release stuff faster.

Gotcha David. The one I'm experimenting with IS temperature dependent. I started using it last fall, and saw immediate (and encouraging) results. Figured I'd finally found the "silver bullet" of fertilizers, and my problems were solved forever---apply it twice a year, and "forgedaboud it". Used it in the (warm) greenhouse all winter, but started noticing a "general decline" as we moved into spring. Plants were yellowing, and became particularly susceptible to spider mites. I threw some good old 20-20-20 liquid fertilizer on them (I think it was Schultz), and they responded almost immediately! My conclusion is simply that there is no "perfect" fertilizer. It's up to us growers.
Now here's a question for you: I'm using a temp-dependent time release. I store the unused fertilizer in it's original bag in an unheated shed. The temps in that shed can often exceed 100 degrees, meaning the pellets release their nutrients like crazy. Where do those nutrients go? I guess the bottom line question is, is there a shelf-life on these products?
Ardesia; becoming convinced once again that "the old ways are the best ways". Will continue my experimentation with slow-release fertilizers, but I'll have a gallon or two of "hot flash" liquid fertilizer available for emergencies...nothing I've found so far beats attentiveness...

Today's bloom:

Hey Stono

As long as the time release isn't wet the nutrients aren't going anywhere. It isn't until you apply water to the pells that they release their load. That's why they can stay on a store shelf.

As far as the perfect fertilzer goes it's the fertilizer that you use that's perfect. Most folks don't use fert so anything is better than nothing. I do advocate time release if my customer doesn't want to hassle with liquid or can't remember to use it. But, if you do use it try and get a brand that has all of the micro nutrients because if you're going to use fert you might as well get the best you can.

David

David,

In regards to providing all the minor-elements. I've heard palm fertilizer can be a good choice for some hibiscus. Is this true?

Hi

If the palm food has the correct numbers and the micro nutrients then yes it would be good. Palms and hibs should share approx. the same needs. But don't let labels fool you. Companies name products as hib food or palm food or orchid food but then don't really have the correct make-up. We have a company here that has a product for hibs but the numbers are completely wrong. I have tried to contact the company but they frankly just don't care. People see palm food and automatically assume it's correct...but often it's not. Look at the numbers. That's what's important.

Hope that helps

pic is Enchantress

David

Thanks David. I'll be out tonight trying to find a good balance. I'm looking for a 15-5-15 I think. Or should I get a higher middle number for blooming purposes? I'll make sure whatever I get has the micro-elements. Chances are I'm also going to get a slow release formula for a change.