Chrysanthemums (mums) are a favorite choice for adding late-season color to gardens and porches, celebrated for their dense, vibrant blooms that continue long after many other flowers have faded. While they are generally easy to care for, successful flowering and overall plant health depend almost entirely on consistent hydration. Understanding the right watering frequency and technique is the most important factor in keeping mums thriving from the time they are purchased until the first hard frost.
Routine Watering Versus Deep Soaking
Watering a chrysanthemum involves two distinct approaches: routine maintenance and thorough deep soaking. Routine watering is the regular application of water to the soil surface to maintain consistent moisture, typically needed daily or every other day for container plants in warm weather. This method aims to keep the root zone evenly damp, preventing the shallow root system from drying out completely. Deep soaking is a less frequent but far more impactful technique designed to fully saturate the entire root ball. For plants in the ground, deep soaking means slowly applying water until the top six inches of soil are thoroughly moistened, encouraging roots to grow deeper. For potted mums, the technique is different.
The most effective deep soaking method for potted mums is bottom-watering. This involves placing the pot into a basin or bucket containing a few inches of room-temperature water, allowing the plant to absorb moisture from the drainage holes upward. The mum should remain in the water for 30 minutes to one hour, giving the compressed soil and dense roots time to fully rehydrate. The process is complete when the surface soil appears moist and the entire pot feels significantly heavier.
Recognizing When Mums Need Rehydration
Instead of relying on a fixed schedule, the most accurate way to determine a mum’s need for water is by looking for physical indicators. The simplest method is the “finger test”: insert a finger one to two inches deep into the soil near the plant’s base. If the soil feels dry at that depth, water the plant thoroughly. For container mums, a physical weight check is also reliable; a pot that feels surprisingly light signals the soil has lost most of its water content and needs immediate soaking.
Visual cues from the plant itself are also helpful, though they represent a later stage of water stress. A mum that is ready for water may display a subtle dullness in its leaves or a slight, temporary droop, especially during the hottest part of the day. Wilting that persists into the evening or morning is a sign of severe dehydration and requires immediate deep soaking to prevent permanent damage. However, wilting can also be a sign of overwatering, so checking the soil moisture first is a necessary diagnostic step.
Environmental and Plant Factors Affecting Frequency
The frequency of deep soaking changes based on several environmental and physical variables. Climate and seasonal conditions play a large role, as mums require much more frequent watering during hot, sunny, and windy summer or early fall days. Conversely, during periods of cooler, overcast weather or regular rainfall, the interval between deep soaks can be extended. The type of container and the soil composition also directly influence how quickly a mum dries out.
Mums planted in the ground retain moisture better and typically need deep watering only about once per week. Plants in containers, especially those in smaller pots or porous terracotta, experience faster evaporation and often require daily checks and more frequent soaking. Furthermore, the plant’s stage of growth dictates its water demand. Mums that are actively blooming use more water to support their vibrant flowers, necessitating higher hydration frequency, while newly planted mums are vulnerable to drying out until roots are established.