Chrysanthemums (mums) are a popular choice for adding a burst of color to the garden, especially during the fall season. These versatile plants, often grown as perennials, require specific conditions to establish a strong root system. Successful growth begins with the proper planting technique. The depth at which the plant is placed in the soil is often overlooked, yet it determines its long-term health and survival.
Preparing the Soil and Location
Before planting a mum, select the right spot and prepare the soil. Chrysanthemums require full sun, meaning at least six hours of direct sunlight daily, to produce vigorous growth and plentiful blooms. Insufficient sunlight leads to weak, leggy stems and fewer flowers. The soil must also offer excellent drainage, as mums will not tolerate consistently wet conditions, which quickly lead to root rot.
The planting area should be loosened to a depth of 8 to 12 inches. Working in organic matter, such as compost or aged manure, improves the soil’s fertility and drainage. The hole should be two to three times wider than the mum’s root ball. This width allows the roots to easily spread into the loosened soil, promoting faster establishment. The depth of the hole should not exceed the height of the root ball itself.
Achieving the Ideal Planting Depth
The correct planting depth is achieved when the top of the root ball is level with the surrounding garden soil. In heavy clay soils, position the top of the root ball slightly above the existing soil line. This encourages faster water runoff away from the plant’s crown and prevents the stem from remaining saturated.
Planting the mum too deep can lead to stem and crown rot due to poor air circulation and excessive moisture retention. Conversely, planting too shallowly leaves the delicate root system exposed to rapid drying and temperature fluctuations. Before placing the plant in the prepared hole, gently score or tease apart any tightly coiled roots. This action breaks the circular growth pattern and encourages the roots to grow outward into the native soil.
Once positioned, backfill the hole with the amended soil, carefully packing it around the root ball. Avoid compacting the soil too firmly, which restricts oxygen flow to the roots. Apply enough pressure to eliminate large air pockets. Maintaining the crown’s position at or just above the soil line protects the plant from moisture-related diseases.
Caring for Newly Planted Mums
Immediate and thorough watering is the first step after planting to ensure the mum’s establishment. The water settles the soil particles around the newly disturbed roots and eliminates any remaining air pockets. Newly planted mums require consistent moisture until they are established, often meaning watering a few times a week in warmer weather, ensuring the water reaches the entire root zone.
Applying a layer of organic mulch is beneficial for moisture conservation and temperature regulation. A layer two to four inches thick helps keep the soil evenly cool and reduces water evaporation. Pull the mulch back a few inches from the central stem, creating a small ring of bare soil. Mulch piled directly against the plant’s crown traps excessive moisture, increasing the risk of stem rot and fungal diseases.