Stock flowers (Matthiola incana) are popular garden additions recognized for their tall, dense spikes of fragrant blossoms. These blooms, which often carry a sweet, spicy scent, are a staple in cottage gardens and cut flower arrangements. Deadheading involves removing spent blossoms and their supporting stem. This maintenance task channels the plant’s energy away from reproduction and into vegetative growth, improving the plant’s appearance and extending its flowering display.
Recognizing When to Make the Cut
The main purpose of removing faded flower stalks is to interrupt the plant’s natural reproductive cycle. Once pollination occurs, Matthiola incana begins to form seed pods, a process that demands a significant amount of the plant’s stored energy. By removing the flowers before this energy-intensive phase begins, you redirect those resources back into the plant’s root system and foliage, encouraging the development of new flowering side shoots.
The proper timing for deadheading is signaled by clear visual cues on the flower spike. You should look for the lower florets on the stalk to begin browning, wilting, or drying out. It is important to act before the entire stalk is spent and the plant has started to form noticeable green, swollen seed capsules.
Acting quickly after the majority of the flowers on a spike have faded prevents the plant from using its resources to mature those seeds. Delaying the cut means the plant has already committed significant energy to reproduction, reducing the likelihood of a successful second flush of blooms. Regular inspection throughout the blooming period will maximize the number of reblooms you can achieve.
The Precise Deadheading Technique
Before making any cuts, ensure your tools are clean and sharp to prevent damage and disease transmission. Bypass snips or sharp floral scissors are the ideal tools for making a clean, precise cut. A clean cut heals faster and minimizes the risk of bacterial or fungal infection.
To deadhead, follow the spent flower stalk down the main stem to the next set of healthy, full leaves. Alternatively, locate a visible lateral bud or side shoot forming in the leaf axil (the angle between the leaf and the stem). This node is the point from which new growth will emerge.
Make your cut on a slight angle, positioned just a quarter-inch above that healthy leaf set or the lateral bud you have identified. Cutting at this specific point encourages the dormant bud beneath to activate and begin developing a new flowering stem. Removing the entire stalk down to the base is unnecessary and removes potential sites for future blossoms.
If the entire plant has finished its first major bloom cycle and appears leggy, you may need to cut back several inches to a lower, stronger set of leaves closer to the ground. This more aggressive pruning forces the plant to bush out and initiate new stems from lower growth points. Always aim to leave some healthy foliage to support photosynthesis and the plant’s recovery.
Maximizing Rebloom and Plant Health
Following deadheading, the Matthiola incana plant requires consistent support to generate a second round of flowers. The plant is actively investing energy into new growth, meaning its water and nutrient needs temporarily increase. Maintaining consistent soil moisture is important, especially during low rainfall, as drying out can cause stress and halt new bud development.
To fuel new stem and flower production, consider applying a diluted liquid fertilizer immediately after cutting. A balanced formulation slightly higher in phosphorus (the middle number of the N-P-K ratio) is beneficial, as phosphorus supports flower development. Avoid high-nitrogen feeds, which promote leafy growth at the expense of new blooms.
While deadheading significantly increases the probability of reblooming, managing expectations is helpful. The subsequent flush of flowers often consists of shorter spikes or less densely packed blossoms compared to the initial spring bloom. The success of reblooming also depends heavily on the ambient temperature, as stock flowers perform best in cooler conditions and may struggle to produce new flowers during intense summer heat.