Hibiscus are remarkable shrubs with vibrant flowers that thrive in containers, offering years of enjoyment. However, tropical hibiscus (Hibiscus rosa-sinensis) is sensitive to cold weather. If temperatures dip below freezing in your area, it’s crucial to bring your container-grown hibiscus indoors during the winter months. Fortunately, caring for them indoors during this time is not overly challenging. Here is what you need to do.
Please note that this guide specifically pertains to H. rosa-sinensis, also known as tropical hibiscus. Other species such as Rose of Sharon (H. syriacus) and hardy hibiscus (often H. moscheutos) have varying degrees of cold-hardiness.
Winter Care Guide for Hibiscus
If you had a potted hibiscus on your patio during the summer, you are already ahead in preserving it through winter. When transitioning a tropical hibiscus indoors, it still requires ample light but may need reduced watering and no fertilizer. Additionally, keeping an eye out for pests is essential.
Light
Tropical hibiscus thrives in full sun, which can be a challenge when moving them indoors. Lower light levels not only slow growth but also weaken the plant’s vigor, making it more susceptible to pest and disease issues. At a minimum, place your hibiscus near a draft-free south or west-facing window that receives strong sunlight even in winter. In regions with short days and diminished sunlight, consider using a grow light in the morning and evening to maintain your hibiscus’ well-being.
Soil Moisture
Similar to outdoor conditions, indoor hibiscus prefer evenly moist soil that is not waterlogged. Proper drainage is crucial, especially when bringing plants indoors. If you lack a large saucer, consider using an aluminum roasting tray or a shallow plastic bin to collect excess water. With slower growth in winter, your hibiscus will require less water than in summer. Check the soil moisture by feeling it with your finger; it should be damp but not saturated. Water deeply when the soil starts to dry out.
Fertilizing
While tropical hibiscus benefit from regular fertilization in summer, they require less in winter as growth slows down. Over-fertilizing in winter can be detrimental as the plant isn’t actively growing. Reduce fertilizer application as autumn approaches and refrain from fertilizing in winter unless signs of nutrient deficiency appear. Resume fertilizing in spring when the plant can be moved outdoors.
Quarantining
If you have other houseplants, consider quarantining your hibiscus for a week or two before placing it near them. Pests and diseases can be inadvertently introduced indoors when bringing plants inside for winter. Monitor your hibiscus closely in a separate space with less light for a week to ensure it’s free of any issues before relocating
Pests can pose a threat to outdoor hibiscus plants, but nature often lends a hand in controlling them. Factors such as heavy rain, bright sunlight, and the presence of birds can help keep pests at bay. Healthy, robust plants are naturally more resilient to diseases and pest infestations. However, when hibiscus plants are brought indoors during the winter months, they become more susceptible to pest attacks. Therefore, it is essential to remain vigilant and proactive in addressing any issues that may arise to ensure the well-being of your hibiscus.
Regular inspection is key to early pest detection. Using a bright light, carefully examine the undersides of leaves, stems, and buds on a weekly basis. Common pests to watch out for include spider mites, aphids, thrips, and others. Should you notice any signs of infestation, promptly address the problem by using horticultural oil or insecticidal soaps. Alternatively, you can try placing the plant in your bathtub and using a strong water spray to dislodge the pests. Repeat this process if necessary until the issue is fully resolved.
Additionally, pruning may be necessary to maintain the shape and size of your indoor hibiscus plants, even during the winter season. Despite their slower growth indoors, hibiscus plants can still produce new branches and shoots that may require pruning. It is important to note that hibiscus plants bloom on new growth, so pruning will not inhibit flowering, although it may slightly delay it.
As the weather warms up in spring, your hibiscus will eagerly await its return to the outdoors. After spending the winter indoors, the plant needs to be gradually acclimated to its outdoor environment to prevent shock. Begin by placing it in a shaded area outside, gradually increasing its exposure to direct sunlight by an hour each day. After approximately 10 days of this process, your hibiscus should be ready to be relocated to its summer spot.
When transitioning your hibiscus outdoors, ensure that nighttime temperatures remain above 50°F to prevent any damage to the plant. During sudden cold spells in the early spring, bring the plant back indoors for protection. Once the hibiscus has successfully acclimated to its outdoor surroundings, resume regular fertilization routines for optimal growth. Remember that during the summer months, the plant will require more frequent watering compared to the winter season.
By following these care tips and remaining attentive to the needs of your hibiscus plants, you can help ensure their health and vitality throughout the changing seasons. By providing proper care and attention, your hibiscus plants will thrive and reward you with their vibrant blooms and lush foliage.
