From my perspective as a Lupinus, timing is everything. My life cycle is governed by the seasons, and a major disturbance like division must be scheduled during my period of least stress. The absolute best time is in the early spring, just as you see my new, green shoots emerging from the crown, but before I have invested tremendous energy in flower stalk production. At this time, the soil is cool and moist, and my active growth phase is beginning, which means I can quickly regenerate the root fibers you will inevitably damage. Alternatively, you can perform this task in the early autumn, after my summer blooms have faded and the intense heat has passed. This gives me several weeks of cool weather to re-establish my root system in my new location before the ground freezes.
Please approach this task with gentleness. Begin by thoroughly hydrating the soil around my base a day before the operation; this reduces transplant shock and makes the soil easier to work with. Using a sharp, clean spade, dig a wide circle around my central crown, giving a generous berth to ensure you get as much of my deep taproot and surrounding feeder roots as possible. Carefully lift the entire root ball from the ground. Now, with a sterilized, very sharp knife or even two garden forks placed back-to-back, you must divide my crown. Gently but firmly pry or cut me apart into smaller sections. Each new division must have several healthy shoots (eyes) and a substantial portion of my root system attached to survive. I am a perennial with a tough crown, but this is a major surgery for me.
My success in a new location is entirely dependent on the preparation you undertake. I thrive in well-draining soil and require a site that receives full sun to partial shade. Before I arrive, please amend the planting hole with some compost to give me a nutrient boost, but avoid high-nitrogen fertilizers as they can promote excessive leaf growth at the expense of my beautiful flowers. The hole should be twice as wide as my root ball to allow my lateral roots to spread out easily, and deep enough so that my crown will sit at the same soil level it was growing at before. This is critical; planting too deep can cause my crown to rot.
Place my divided section into the center of the prepared hole, gently spreading out my roots. Backfill with the native soil, firming it gently around my base to eliminate any large air pockets. Water me deeply and thoroughly immediately after planting; this settles the soil around my roots and provides essential hydration. To help me conserve moisture and reduce weed competition, apply a light layer of mulch around my base, but be sure to keep it away from directly touching my new shoots to prevent rot. For the first few weeks, monitor my soil moisture closely. I will need consistent watering as I am no longer supported by my original, extensive root system and am working hard to establish myself anew.
