Growing this perennial herb in a container is the most effective method for the average owner, primarily because it controls the plant’s aggressive, mint-like spreading habit. A potted environment allows the plant to be moved outdoors for optimal growth or indoors for protection and easy access. This controlled environment ensures a steady supply of fresh foliage and flowers, which contain the nepetalactone compound that causes the characteristic euphoric effect in many cats.
Preparing the Pot and Soil
The pot must have sufficient drainage holes at the bottom, and a material like unglazed terracotta is often recommended as it allows excess moisture to evaporate through the container walls, which helps regulate soil wetness. Proper drainage is the single most important factor to prevent root issues. For a mature plant, choose a container that is a minimum of 8 to 10 inches in diameter to provide ample space for the root system to develop.
Catnip thrives in conditions that mimic its native, somewhat lean environment, preferring well-draining soil rather than rich, heavy mixes. Use a standard, high-quality potting mix, but amend it with perlite or coarse sand to increase porosity and ensure fast drainage. When ready to plant, a nursery start can be transplanted at the same depth it was previously growing. Seeds should be lightly covered with soil or sown on the surface, as they often require light to germinate.
Ongoing Light and Water Needs
The plant requires at least six hours of sunlight daily, with full sun exposure being ideal for robust, dense growth. While it can tolerate partial shade, insufficient light will cause the stems to become elongated and weak, a condition known as “legginess”. If growing indoors, a south-facing windowsill is generally the best placement, but the pot should be rotated weekly to ensure all sides of the plant receive adequate light exposure.
Watering potted catnip requires careful attention because the container environment dries out much faster than garden soil, yet the plant is highly sensitive to overwatering. The most reliable practice is to allow the top inch or two of the soil to dry out completely between waterings. Soggy conditions can quickly lead to root rot, so a deep watering when the soil is dry is better than frequent light sprinklings.
Catnip is naturally adapted to poor or moderately fertile soil. Over-fertilizing, particularly with high-nitrogen formulas, can result in excessive leafy growth that is less potent for your cat. If the plant appears to need a boost, apply a balanced liquid fertilizer at half-strength only once or twice during the active spring and summer growing season.
Harvesting and Maintenance Pruning
The timing of the harvest is directly linked to the concentration of nepetalactone. The leaves and flowering tops are at their peak potency just as the plant begins to flower, which typically occurs in mid-summer. When harvesting, use sharp, clean scissors or shears to cut the stems just above a leaf node. This specific cutting location encourages the plant to branch out, resulting in a fuller, bushier plant.
To prepare the harvest for long-term storage, the leaves and flowers should be dried quickly and thoroughly to prevent mold. The easiest method is to bundle the cut stems and hang them upside-down in a cool, dark, and well-ventilated area for one to two weeks until they are brittle. Once fully dried, the plant material should be crumbled and stored in an airtight container away from heat and direct light to preserve the volatile oils that contain the nepetalactone.
Maintenance pruning is necessary to keep the container plant vigorous and attractive. Removing the spent flower heads, a process called “deadheading,” prevents the plant from setting seed, which can weaken the plant and lead to unwanted self-sowing. Pruning back long or “leggy” stems in the spring and early fall promotes the dense, compact growth that is preferable in a pot.