Summer dormancy is a natural survival strategy for certain plants, allowing them to cope with challenging hot and dry conditions by pausing active growth. During this period, their care requirements change dramatically, primarily involving a significant reduction in watering and the cessation of fertilization.

Understanding and respecting these natural cycles will help your plants remain healthy and rebound vigorously when conditions become favorable again.

What is Summer Dormancy and Why Do Plants Do It?

Summer dormancy, also known as aestivation, is a period when a plant temporarily ceases active growth and enters a resting state. Unlike winter dormancy, which is triggered by cold temperatures and short days, summer dormancy is a response to high temperatures, intense light, and drought conditions, which are common in many arid and Mediterranean climates.

Plants enter dormancy to conserve resources and avoid stress. During this time, they may shed leaves, die back to the ground, or simply slow down their metabolic processes to an almost imperceptible crawl. This strategy allows them to survive until cooler, wetter conditions return, preventing damage and ultimately ensuring their long-term health and ability to reproduce.

Which Plants Experience Summer Dormancy?

Many plants, particularly those native to regions with hot, dry summers, have evolved to exhibit summer dormancy. Recognizing these plants is the first step in providing appropriate care.

Bulbs and Corms

Several popular flowering bulbs and corms go dormant in summer after their spring or early summer bloom. Examples include cyclamen (Cyclamen persicum), calla lilies (Zantedeschia aethiopica), and some gloxinias (Sinningia speciosa). After flowering, their foliage often yellows and dies back, indicating they are preparing for their resting period.

Succulents and Cacti

While many succulents are active growers in summer, some species, particularly those from winter rainfall regions, enter dormancy during the hottest months. For instance, certain adeniums (Adenium obesum), anacampseros (Anacampseros rufescens), and specific types of euphorbias may reduce or halt growth. They often exhibit signs like shriveling leaves, color changes, or a general lack of new development.

Other Mediterranean and Arid Plants

Beyond bulbs and succulents, many plants native to Mediterranean climates, characterized by hot, dry summers and mild, wet winters, exhibit summer dormancy. This can include some ornamental herbs, shrubs, and geophytes (plants with underground storage organs) that become less active or lose foliage when summer heat arrives.

How Do I Adjust Care for a Dormant Plant?

Adjusting your care routine is crucial when your plant enters summer dormancy. Continuing to water or fertilize a dormant plant can lead to root rot or other health issues. Here's how Planta recommends caring for your summer sleepers:

• Drastically reduce watering: This is the most critical adjustment. Once foliage starts to yellow or die back, reduce watering significantly. For many plants, this means watering only once a month, or even every 6-8 weeks, just enough to prevent the bulb or rhizome from completely drying out. For succulents, stop watering entirely once they show signs of dormancy and resume only when you see signs of new growth in fall.

• Stop fertilizing: Plants do not need nutrients when they are not actively growing. Fertilizing a dormant plant can burn its roots or stimulate weak, unwanted growth. Resume fertilization only when new growth emerges after the dormancy period.

• Adjust light: While some plants might tolerate their usual bright indirect light, moving dormant plants to a slightly cooler, shadier spot can be beneficial, especially if their foliage has died back. Avoid intense, direct summer sun that can scorch dormant plant tissues.

• Ensure good air circulation: Keeping the air moving around dormant plants, especially those that prefer drier conditions, helps prevent fungal issues that can arise if the soil remains damp without active plant uptake.

• Avoid repotting: Repotting is stressful for a plant. Always wait until a plant is actively growing to repot it, ideally at the beginning of its active growing season.

How Can I Tell if My Plant is Dormant or Dying?

It can be worrying to see your plant change, but there are key differences between dormancy and distress:

• Natural progression: Dormancy typically follows a predictable pattern. For instance, a cyclamen will bloom, then its leaves will yellow and die back. If your plant is known to be summer dormant, these signs are likely normal.

• Even yellowing/drying: Dormant leaves often yellow evenly before drying and falling off. If you see sudden browning, black spots, or mushy stems, these might be signs of overwatering or disease, not dormancy.

• Healthy base: For bulbs and corms, the underground storage organ should remain firm and healthy, not soft or rotten. For succulents, the main stem or base should feel robust.

• No pests: A dormant plant should not be infested with pests. If you see insects or signs of their activity, the plant is likely struggling and needs attention, not just rest.

By observing these cues, you can confidently distinguish a healthy, resting plant from one that needs urgent intervention.

Embracing summer dormancy means giving your plants the break they need to thrive. By recognizing the signs and adjusting your care with less water and no fertilizer, you're not neglecting them, but rather supporting their natural life cycle and ensuring they emerge refreshed and vibrant for their next active growth phase.