Hibiscus Plant Care – Best Fertilizer, Pesticide, Soil PH, & Temperature

Hibiscus flowers can bring colors and life to any garden. These flowers come in vivid colors and in single petal and multi petal variety. Non GMO variety of hibiscus flower is smaller in size, but the hybrid variety can be as big as our hand! If you love these flowers, you can not stop at having just one or two varieties of hibiscus.

If you have a Hibiscus flower plant at your home, or if you are planning to add one, then read this article till end as it will help you in understanding the needs of this shrub/plant and then you can take care of this exotic flowering plant like a pro.

Hibiscus Plant Care Tips

Best Temperature for Hibiscus

Hibiscus likes hot and humid topical climate with lots of rain.

It is a pretty hardy plant and can tolerate temperatures between 34°F (1ºC) to 115°F (46ºC).  However, you see best growth and heavy blooming only when temperature is between 60°F to 95°F (15 to 35°C).

If temperature drops below 50°F (10°C) at night, then the plant enters dormancy and stops growth. It starts growth again when night temperature rises to 60°F (15°C) or more.

If temperature drops below 32°F (0°C) at night, then hibiscus will not survive. If you live in an area where you see temperatures below freezing, then you should not plant hibiscus in ground. Plant it in a large pot and move it indoor (close to a window that gets sunlight) during winters.

At temperatures above 100°F (38°C), it starts to get some stress and may drop flower buds. You may also notice its leaves showing signs of burning. You can avoid all this by watering your hibiscus daily. Don’t allow its soil to dry out during hot summers.

Sunlight Recommendation for Hibiscus

Hibiscus likes full sunlight and should be planted in an area that gets 2 to 8 hours of direct sunlight depending on temperature in your location during summers.

Hibiscus Red Flower Multi-Petal

So, if you are located in a place where temperature remains in the range of 60°F to 95°F (15 to 35°C) for the whole year, then you can plant hibiscus in a location that receives direct sunlight for 6 or more hours per day.  On the other hand, in cities that see temperature between 40°F to 116°F (5 to 47°C), the summers are very harsh. Here you should plant hibiscus in an area that gets 2 to 3 hours of direct sunlight. Similarly, you can make adjustments depending upon maximum temperature you see in your area.

If you don’t have a place with shade, then make use of green nets during summers.

If you plant hibiscus in a pot, then you have the flexibility of moving the pot to a suitable location depending on the season.

Soil PH for Hibiscus

Hibiscus likes neutral to slightly acidic soil between 6.2 and 6.8 PH. If your hibiscus are not doing well, then check the PH of soil. You can alter the soil PH by using Lime (to increase PH) or by using Sulphur or Alum ( to decrease PH). Wait at least 1 week before re-testing the soil to ensure that the pH levels are ideal for growing hibiscus.

Best Fertilizer for Hibiscus

Hibiscus, especially the hybrid variety is a vigorous grower that keeps producing large sized flowers almost entire year except in the winters. To support that kind of growth, color pigmentation, and heavy flowers, it needs well developed root system, healthy leaves, and strong branches. For all this, we need to give it a proper fertilizer or the growth and flowering will suffer.

Hibiscus Pink Flower

The best fertilizer for hibiscus is worm casting or vermicompost. You can add a hand full of worm casting fertilizer every 30 days during blooming season in summers. It is the best fertilizer for Hibiscus without a doubt.

Commercial fertilizers are not usually necessary for hibiscus. However, if you want, you can use potassium nitrate as booster fertilizer for maximizing the blooms. However, don’t add it too often. Once in early spring and once after rainy season is enough.

Avoid fertilizing during winters.

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Fertilizers to avoid:

Bloom Booster (or similar) fertilizer, DAP (Di-ammonium Phosphate), NPK with high ratio of phosphorus, Rock Phosphate, Bone Meal, or any other chemical fertilizer with high percentage of phosphorus should be avoided. This is because Hibiscus needs very little amount of phosphorus and in high doses, it will slowly damage hibiscus plants over time.

If you have used chemical fertilizers and are seeing yellowing of leaves, bud drying, etc, then change the soil around your hibiscus and replace with vermicompost and garden soil mix (1:2).

Though we advise against it, but if you are still planning to use chemical fertilizers, opt for products that are high in potassium and low in phosphorus. For example, you can use Potassium Nitrate (13-0-45).

Watering Requirements for Hibiscus

Watering requirements of hibiscus plant vary with season.  During winters water it only when the soil has gone dry.

However, water them daily during summers. If required, water them twice a day. Just make sure that the water drains out within few minutes and there is no water standing near it.

Hibiscus Yellow Flower

Still, its possible that during harsh summer, you see buds drop. If this happens, move hibiscus to a shadier place and/or increase the frequency of watering.

Even with this treatment there may be times in summer when blooms just don’t open. This is quite normal in areas that get harsh summers. Don’t get too worried about it. Hibiscus will begin to bloom again when the summer wanes.

Pest Control Tips for Hibiscus

One of the main drawbacks of Hibiscus plant is that it gets affected by frequent pest attacks. Aphids, Mealy bugs, thrips, and spider mites are common hibiscus pests. In addition to that, it also gets affected by fungal diseases like dieback, powdery mildew, etc.

Its important that you start tacking these problems as soon as they occur. It is often difficult to control pests and diseases once they affect the whole plant.

You can treat infestations by spraying the plant with a water hose. If that does not help, then spray neem oil and soap solution.

For fungal infections, a fungicide or Neem Oil spray.

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In the long term, it’s important to keep your hibiscus plant healthy and well pruned so that it can fight the diseases and pests itself.

Another natural way of keeping control over pests like aphids is to let Ladybugs thrive in your garden. These usually harmless bugs, eat aphids and keep hibiscus healthy and pest free.

Hibiscus Blooming Time & Pruning

Hibiscus blooms during summer when it gets atmospheric temperature of 60°F to 95°F (15 to 35°C). As long as it gets this temperature, it keeps blooming. Blooming stops when the night temperature dips below 60°F (15°C).

Hibiscus flower lasts only a day before closing and falling off the plant. It is important to keep the plant tidy by removing the spent flowers and dead branches. This should be done on regular basis.

Other than that, Hibiscus should be pruned every year by one-third in late winter or early spring. Heavy pruning is not advisable.

Best Potting Mix for Hibiscus

Hibiscus likes soil that is moist but well-drained.  So, we recommend a mixture of two parts potting soil, two parts of vermicompost and one part of peat moss.

Clay soils should be avoided, but, if necessary, you can improve heavy clay by mixing in sand.

Frequently Asked Questions.

How to Treat Yellow Leaves on Hibiscus?

There can be several reasons why hibiscus leaves turn yellow. We have covered this topic in a separate article on this website. In short, make sure that you are not over watering or under watering the plant. Look for pest and fungal infestation, particularly for spider mites on the underside of leaves. If you suspect a fungal infection or pest attack, spray SAAF & Neem oil. In case of micronutrient deficiency, spraying with chelated iron or any other micronutrient supplement can solve the issue temporarily. For long term solution, check the soil PH and adjust it to 6.2 to 6.8

Why is my hibiscus not producing flowers?

This can happen due to less sunlight exposure, lower atmospheric temperature, under watering, or excessive use of wrong (chemical) fertilizers. Most people don't realize that ordinary chemical fertilizers like DAP, NPK, Rock phosphate, bone meal, etc can harm hibiscus. Excessive phosphorous reduces hibiscus blooms by immobilizing nutrients in the soil.

What causes bud drop on hibiscus plants?

Bud drop usually happens due to pest infestation or temperature changes. While you can't do much about climatic changes, you can surely control the pest infestation by spraying an insecticide.

Why are bud not opening on hibiscus plants?

This can happen due to nutrient deficiency, pest attacks, or change in temperature. Depending on the reason, you can fix this problem by spraying insecticide, using NPK 16-8-24, or by moving hibiscus plant to a better location.

Final Words

We are sure if you follow the Hibiscus plant care tips provided in this article, you will have more hibiscus flowers, brighter colors, and over time, stronger branches and roots.

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