Hibiscus flowers are large, colorful blooms that steal the show despite only lasting a day or two. However, to produce lots of these beautiful flowers, hibiscus plants need lots of water. In this article, we’ll look at the watering requirements for hibiscus plants.
The Importance of Watering Correctly
Water is crucial for hibiscus plants because it’s an essential part of photosynthesis. During photosynthesis, plants mix solar energy and carbon dioxide absorbed through their leaves with water absorbed through their roots. This produces glucose that is then used as fuel to manufacture cellulose – the basic material of plant tissue.
Because water is so crucial in cellulose production, up to 95% of a plant’s total mass can consist of water. When their roots absorb water from the soil, plants also take in important nutrients like nitrogen, phosphorus, and potassium. These nutrients are used to produce healthy leaves and develop flower buds.
When to Water Hibiscus Plants
Hibiscus plants are divided into two types; hardy hibiscus and tropical hibiscus. Hardy hibiscus grows in USDA Zones 4 to 9 and can survive winter temperatures down to -30ºF. Tropical hibiscus grows in warm, humid climates in Zones 9 to 12.
Despite their different temperature requirements, these two types of hibiscus have the same water requirements. Hibiscus are thirsty plants that like slightly moist soil at all times. This is because hibiscus flowers only last for one or two days. As such, these plants have to produce lots of flowers throughout the growing season.
Most hibiscus plants require a couple of inches of water every week from spring until late fall. Water hibiscus plants whenever the top inch of soil feels dry to the touch. You may have to water more frequently in periods of dry weather.
Seasonal Changes to Consider
The amount of water that hibiscus plants need can change slightly depending on seasonal factors. During hot, dry summers, hibiscus plants need to be watered more frequently. In some areas, you may have to water your hibiscus once or twice a day.
In Zones 9 to 12, tropical hibiscus are evergreen plants that can bloom throughout the year. This means that they require watering all year round. Give tropical hibiscus 1 to 2 inches of water each week, even in winter.
Hardy hibiscus are deciduous plants that inhabit colder areas in Zones 4 to 9. Unlike tropical hibiscus, hardy hibiscus goes dormant in winter once they’ve dropped their leaves. Water your hibiscus less frequently during these inactive periods.
How to Water Hibiscus Plants
Watering hibiscus plants correctly enables your plant to get enough water while reducing the risk of diseases or pests. Here’s a quick guide detailing how to water hibiscus plants:
Check that the top inch of the soil feels dry before watering. This helps prevent overwatering. Most hibiscus needs 1 to 2 inches of water each week during the growing season.
Aim your watering can at the base of the plant and water the soil. Avoid getting any water on the leaves or flowers, as this can lead to diseases like powdery mildew.
Signs of Overwatering
Although hibiscus plants need slightly moist soil, too much water leads to serious problems like root rot. The main symptoms of overwatering include:
- Brown, mushy, or smelly roots
- Drooping, wilting, or yellowing leaves
- Soil feels waterlogged for long periods
- Stunted growth
Signs of Underwatering
Because they need consistent moisture, hibiscus plants can struggle if they dry out too much, especially during hot summers. Common symptoms of underwatering include:
- Cracked, dry soil
- Flower buds not opening
- Limp, yellowing foliage
Hibiscus Water Requirements FAQs:
Can Hibiscus Have Too Much Water?
Although hibiscus needs moist soil at all times, they can be watered too much. Overwatering causes problems like root rot, so only give hibiscus plants 1 to 2 inches of water per week.
How Do I Know if my Hibiscus is Overwatered?
An overwatered hibiscus may display symptoms like brown, mushy roots or drooping, yellowing leaves. Leave the plant to dry out a bit, and mix some grit into the soil to improve drainage.
How Much Drainage Does a Hibiscus Need?
Hibiscus plants require nutrient-rich, well-draining soils that can still stay slightly moist. Sandy or chalky soils are unsuitable for hibiscus because they drain too quickly. For more, see our in-depth guide on where to plant hibiscus.
Hibiscus are thirsty plants that need lots of water to produce beautiful flowers. Water hibiscus once weekly, providing 1 to 2 inches of soil each time. Water hibiscus plants more frequently in hot, dry weather to stop them drying out.