Replanting herbs involves moving them from their current container or garden spot into a larger container or a new location. This process is necessary when an herb has outgrown its space, often indicated by roots circling the inside of the pot. Moving the plant provides fresh nutrients and physical space for the root system to expand, ensuring continued vigorous growth. Successful replanting requires careful timing and preparation to reduce stress on the plant.
Preparing for the Transplant
Choosing the appropriate time minimizes stress on the plant. The optimal time of day for transplanting is during the cooler hours, specifically the early morning or late afternoon, or on an overcast day. This allows the herb time to acclimate without the shock of intense midday sun. Perennial herbs should be transplanted in early spring or fall, while warm-season annuals should only be moved once the soil temperature is reliably warm, often above 60°F.
The new container should be only one to two inches larger in diameter than the previous one, as an excessively large container holds too much moisture and can encourage root rot. Adequate drainage is mandatory, so the container must have holes at the bottom to allow excess water to escape.
A commercial, well-draining potting mix is the best choice for the growing medium. Never use heavy garden soil, as it compacts easily and prevents proper aeration. For herbs that prefer drier conditions, such as rosemary or thyme, mix in perlite or coarse grit to improve drainage.
Pre-moisten the new potting mix thoroughly until it is evenly damp but not saturated. Also, give the herb a deep watering 12 to 24 hours before the transplant to ensure the plant’s tissues are fully hydrated, which reduces transplant shock.
Executing the Transplant: A Step-by-Step Guide
Moving the herb requires care to protect the stem and the delicate root system. To remove the herb, gently hold the plant by the base of the main stem, invert the pot, and tap the bottom or squeeze the sides. The herb and its intact root ball should slide out smoothly. Avoid pulling on the stem, which can cause irreparable damage.
Inspect the root ball for signs of being root-bound, which appears as a dense mat of roots circling the outside. Gently massage the root ball to loosen the outer roots and encourage them to grow outward into the new soil.
For severely root-bound plants, scoring is necessary. Use a clean, sharp knife to make three to four shallow, vertical cuts down the sides of the root ball and one across the bottom mat. This stimulates the production of new feeder roots.
Place the herb in the new container or hole, ensuring the top of the root ball is level with the surrounding soil surface. Backfill the container with the pre-moistened soil mixture, gently firming the soil to eliminate air pockets. Firm the soil just enough to stabilize the plant, avoiding heavy compaction that would restrict water and air movement to the roots.
Post-Transplant Care and Recovery
Immediate care is crucial for the herb’s establishment and recovery. First, water the herb thoroughly and deeply to settle the soil around the disturbed roots and ensure good soil-to-root contact. This initial saturation prevents air pockets from forming. After this, allow the soil to dry out slightly before watering again to prevent overwatering.
Manage the herb’s location to prevent sun scorch. Place the replanted herb in a sheltered spot that receives bright, indirect light or partial shade for the first week. This allows the roots to begin healing without the pressure of high water loss. After about seven days, gradually reintroduce the herb to its final, full-sun location.
Monitor the herb for signs of transplant shock, such as wilting or yellowing leaves. If wilting occurs, ensure the soil is moist and temporarily increase the shade. Avoid applying fertilizer immediately after replanting. Wait four to six weeks, or until you observe clear signs of vigorous new growth, before introducing any nutrients.