By Mark Wolfe | Updated May 25, 2021 10:03 AM

BobVila.com and its partners may earn a commission if you purchase a product through one of our links.

Hibiscus plants look gorgeous at the garden center. The lush, glossy green foliage makes a perfect background for vibrant pink, red, yellow, or orange blooms. But without the proper care, it doesn’t take long for the flowers to droop and the leaves to turn yellow. Not only do these tropical beauties need ample sunlight and consistent moisture, but they also require good nutrition. Consistent feeding with high-quality plant food boosts the health and vigor of all plants, and hibiscus plants are no exception. In fact, these heavy feeders are more sensitive to nutrient swings than many other plants.

The best fertilizer for hibiscus plants must support all phases of growth: foliage, stems, roots, and flowers. With so many available options, knowing which product to buy can be challenging. The list of top picks that follows addresses a variety of gardening styles and plant health concerns. Continue reading for the rationale behind the recommendations and reviews of each product.

It is vital to choose plant food that works within a particular gardening system. Organic gardeners appreciate natural ingredients that support healthy soil, while many other gardeners simply want an effective plant food that delivers the proper nutrients when the plant needs them. Read on for tips about the factors to consider when shopping for the best fertilizer for hibiscus based on your gardening style.

Fertilizer comes in many forms. The first choice most gardeners encounter is liquid versus granular. The primary difference lies in the amount of time it takes for the plants to absorb the nutrients—and how long they last.

The nutrients in liquid plant food are immediately available, delivering visible results within a few days. Whatever the plants don’t absorb at the time of application quickly washes through the soil, so use these products frequently.

Granular fertilizer dissolves gradually, delivering a slow and steady feeding. Results may not be visible until a week or two after application, but the effect may last for 6 weeks or more. Hibiscus plants benefit from a combination of time-release granular for a long slow feed, plus regular applications of fast-acting liquid in times of greater nutrient need, like between bloom cycles.

Plants absorb the nutrients from organic and inorganic fertilizer similarly, but the nutrients are made available differently. Inorganic nutrients dissolve in water and are immediately available for plants to use. Organic plant food must be transformed by soil-dwelling microbes into a form that is usable by plants.

The benefits of inorganic plant food are that it is inexpensive, easy to use, and delivers a higher nutrient load pound-for-pound than organic plant food. But it can lead to a depletion of soil organic content over time. Organic fertilizer is also more likely to burn plants if overapplied.

Organic fertilizer feeds the plant indirectly by first feeding soil microbes. This leads to a healthy increase in soil organic matter and more efficient nutrient use over time. But organic fertilizer works slowly, making it less effective for correcting immediate plant deficiencies.

Nitrogen (N), phosphorus (P), and potassium (K) are the three main nutrients that plants use in large quantities: N for foliage growth, P for root and flower development, and K to regulate a variety of metabolic processes. They are listed on fertilizer packaging as a numerical ratio, such as 10-10-10 or 12-4-8, always in the order N-P-K. These numbers, called the guaranteed analysis, reveal the percentage by weight of each nutrient in the fertilizer mixture.

Hibiscus plants use relatively large quantities of N and K and far less P. At planting time and annually as new growth begins in spring, fertilizer with an analysis like 10-10-10 will provide a balanced startup feeding. For regular feeding, choose a plant food with a fertilizer analysis like 12-4-8 or 17-5-24.

When new leaf growth begins in spring, apply a granular or slow-release fertilizer. This will ensure a mild, steady feed as the plant grows new foliage and forms flower buds. Follow up two or three more times through the growing season with slow-release plant food for consistent nourishment.

Apply liquid fertilizer with high N, low P, and high K content throughout the growing season. Mix the fertilizer at half the recommended strength and feed twice as often for more consistent results. Begin when flower buds start to form and continue through late summer or early fall when the weather begins to cool, and the plant prepares to enter dormancy.

The soil condition refers to physical properties like particle size and compaction. The condition affects moisture retention, drainage, and aeration. Hibiscus plants grow well in moist, well-drained soil that is not tightly compacted. Containers work well, as do well-prepared garden beds. Soil that stays wet is not suitable for these plants.

The amount of organic matter in the soil affects its ability to retain nutrients, such as after fertilizing with liquid plant food. Soil with more organic matter retains fertility longer and more consistently than soil with less. When gardening in the ground instead of containers, use organic fertilizer to support and increase organic content in the soil.

These top picks represent some of the best fertilizers for hibiscus plants. They feature a mix of organic and inorganic and granular and liquid options. All of these fertilizers will work either independently or in combination to promote healthy plants with deep green foliage and an abundance of vibrant flowers.

Carl Pool Hibiscus Plant Food is an inorganic granular fertilizer that delivers 10-4-12 NPK, including 3.34 percent slow-release nitrogen for steady growth. It also includes 10 percent sulfur to balance soil pH; calcium and magnesium for healthy roots, stems, and leaves; and six additional micronutrients to support overall plant health. For regular maintenance, apply it around any potted or in-ground hibiscus monthly for best results. This product comes in a convenient resealable 4-pound plastic jar.

An inorganic option for regular maintenance feeding of tropical hibiscus plants, NELSON PLANT FOOD Hibiscus Food boasts a 10-4-12 NPK analysis, plus six additional micronutrients to boost overall plant health. This combination fertilizer includes both quick-feeding and slow-release nitrogen for continuous nourishment. It’s formulated for use with in-ground and potted plants, so apply it monthly throughout the growing season for best results. This granular product is available in 2-, 4-, 15-, and 25-pound resealable jars.

Scotts All Purpose Flower & Vegetable Food is an easy-to-apply and slow-release 10-10-10 plant food that boosts the soil’s basic nutrient load. This nonorganic granular formula is immediately available for plants to absorb. Each application lasts up to 2 months, making it an excellent backup for regular applications of fast-acting liquid plant food. Only two or three applications per year are necessary to boost the health and vigor of hibiscus and other garden plants. It comes in a 3-pound resealable bag.

Osmocote Smart-Release Plant Food delivers steady, season-long plant nutrition from a single inorganic application. The 15-9-12 NPK analysis is further supported by 6 percent sulfur to balance the soil pH and seven additional micronutrients to support general plant health. Apply it once in the spring, and supplement with liquid plant food throughout the season as needed. This granular product comes in a 1-pound resealable plastic jar.

With a general-purpose fertilizer analysis of 12-4-8, Miracle-Gro Liquafeed is an inorganic formula that is safe to apply every 2 weeks for vigorous growth, deep green foliage, and bright flowers. Use it in combination with slow-release granular plant food for consistent nourishment of heavy-feeding hibiscus. The starter kit includes the hose-end applicator and a 16-ounce Liquafeed concentrate cartridge. Each cartridge covers up to 400 square feet.

Organic products are all about promoting a diverse and healthy soil biome that naturally feeds plants. EarthPods Premium Hibiscus Plant Food does just that with a mild 0.2-0.2-0.4 NPK analysis, plus 70 trace elements, humic acid, fulvic acid, and a host of beneficial microbes. These elements stimulate soil-dwelling fungi and bacteria, increase soil organic matter, unlock native fertility, and enhance nutrient transfer from the soil to the plant. Insert an EarthPod concentrated capsule into the soil at the plant base, and that’s it. Each container includes 100 EarthPods.

Overwatering, drought damage, or general neglect can quickly lead to plant damage and infestation. BAYER CROP SCIENCE All in One Flower Care Granules feed and protect with a single application. The inorganic granular formula includes a 6-9-6 NPK fertilizer, imidacloprid and clothianidin insecticides, and tebuconazole fungicide. Work the granules into the upper soil layer around each plant, and water in thoroughly. Each application lasts for 6 weeks. It is packaged in a 4-pound resealable plastic jug.

Miracle-Gro Performance Organics All Purpose granules offer a 9-2-7 NPK analysis perfect for hibiscus, along with other nutrients that support healthy roots, foliage, and flowers. Results are visible within 7 days, compared to untreated plants. The fertilizer feeds for up to 6 weeks per application. Use this organic fertilizer alone, or supplement with liquid plant food as needed. The product comes in a 2.5-pound reclosable jug.

Keep reading for answers to some of the most frequently asked questions about using fertilizer and hibiscus plant care.

Although a blooming hibiscus makes an attractive gift and a beautiful display, it requires intense light to grow well. For best results, plan on growing hibiscus outdoors, as long as the weather allows. When temperatures dip below 40 degrees Fahrenheit, bring the plants indoors to overwinter them.

Hardy hibiscus, including rose of Sharon and many perennial types, come back year after year in temperate regions. Tropical hibiscus will not withstand freezing temperatures and should be either brought indoors for the winter or considered an annual to be discarded at the end of the season.

Whether they grow in the ground or containers, the care of a hibiscus plant is similar. Grow them in full sun to partial shade. Water them frequently to prevent the soil from drying out. Feed them lightly and regularly. And occasionally loosen the soil surface over the plants’ root zone to promote water and plant food penetration.

Use a combination of balanced organic or slow-release granular fertilizer and high N and K liquid fertilizer. Spread the granular plant food on the soil surface. Apply the liquid by soaking the root zone.

Apply slow-release fertilizer two to four times per year, depending on the length of the growing season. Apply a weak solution (quarter-strength or half-strength) of liquid fertilizer weekly.

Disclosure: BobVila.com participates in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for publishers to earn fees by linking to Amazon.com and affiliated sites.

Copyright © 2022 Acton Media Inc. All rights reserved.