It can be frustrating to get a plant only to find it dying or not growing as well as it should. In most cases, this is a matter of soil quality and fertilizer needs not being met.
There are additional things to consider when living in a less temperate location, such as Florida, where the elements can be much less forgiving than further inland.
Hibiscus is one of many popular plants that can be grown in Florida gardens but needs a little extra attention, such as some midday shade.
When it comes to fertilizers, are there any special rules, and which fertilizer is best?
The Best Fertilizer For Hibiscus In Florida
In its most basic form, you’ll want a liquid-soluble fertilizer with a 3-1-4 NPK.
But things can get a little more complicated when you consider all of the other products out there claiming to be good for hibiscus plants.
Understanding The NPK Ratio
Before going further, we need to understand the NPK ratio and how it applies to your hibiscus.
The N stands for nitrogen, which is essential for full, healthy growth.
The P is for phosphorus, which promotes healthy blooms.
The K is Potassium, which helps the plant grow strong stems and boosts the immune system.
Hibiscus plants use more potassium than most other plants and require far less phosphorus. For this reason, you should aim for a ratio of 3-1-4 or similar.
For example, 10-4-12 and 17-5-24 are both considered acceptable as long as they’re diluted.
WARNING: Know Your Hibiscus
But now we need to go over something else that’s rather important.
Hibiscus isn’t just one plant, and it’s actually an entire genus with literally hundreds of plants and even more cultivars contained within.
This means that the nutritional needs of one hibiscus could be very different from another one.
For the most part, moderate nitrogen, low phosphorus, and high potassium ratio are the way to go.
However, if you want a truly happy, healthy plant, try to identify the exact species or cultivar you have and follow any instructions for that specific plant.
Fertilizers You Should Avoid
There are a lot of fertilizers out there that sound great but can actually harm your hibiscus.
Perhaps the best example of this is the so-called bloom boosters. These fertilizers are high in phosphorus and believed to promote bigger, brighter flower displays.
While this hasn’t been totally proven, one thing is certain – the phosphorus content is precisely what your hibiscus doesn’t need.
Another big no-no is granular slow-release formulas.
The big argument for these is that they allow you to feed your plants only a couple of times per year and will give the plant nutrients over some time.
Unfortunately, this doesn’t work quite as advertised. Instead, the granules are filled with various nutrients that all degrade at different rates.
While a single granule may contain the proper ratio of nutrients, some will degrade fast, flooding the soil, while others degrade at a much slower pace, resulting in a deficiency.
In the end, you’ll just find yourself spending a lot of extra time supplementing the fertilizer with additional fertilizers to try and restore the proper balance.
The Ideal Hibiscus Fertilizer
So let’s bring everything together.
First of all, try to find out the exact species or cultivar of hibiscus you own so you know if it has any particular feeding needs, as this article only gives a basic guideline for hibiscus plants in general.
You’ll want a liquid-soluble fertilizer, as these deliver the nutrients immediately and fully.
Aim for a ratio with a lot of phosphorus, a slightly lower amount of nitrogen, and a low amount of phosphorus.
Follow all package instructions carefully unless your particular hibiscus requires a specific dilution or frequency for feeding.
Always add a touch of water to the soil first, so the fertilizer absorbs better, then finish the watering with the diluted fertilizer.
Cut back on feeding when the plant is dormant to avoid harmful buildup.
Bonus Tip: Tweaking for Perfection
You can do a few things to give your plant even better care, similar to tweaking your own diet as needed.
For starters, testing the soil is a great way to find out if there’s already an abundance or deficiency in particular nutrients.
Knowing this will allow you to tweak the ratio of the fertilizer you buy to better match what your plant needs.
Also, watch your plant as it grows and take notes.
Sometimes when you have two plants of the same species or cultivar, you’ll find they have very different personalities.
You may find that slightly tweaking how far you dilute the fertilizer may positively affect a particularly finicky plant, such as diluting to ⅕ as opposed to ¼.
Finally, don’t forget that your hibiscus needs other nutrients, such as copper, iron, or magnesium.
These should be listed somewhere on the fertilizer packaging, but you’ll probably have to hunt for this additional nutritional info which isn’t featured prominently like the NPK ratio.