How to Take Softwood Cuttings
Given the right care, plants can root from stem cuttings in spring or summer.
Nonflowering shoots of many tender perennials and patio plants, as well as some herbaceous perennials, including delphinium and lupine, will root in six to eight weeks in warm, humid conditions in summer. Cuttings are prone to disease, so sterilize any knives, pots, and trays used in their preparation, and root them in fresh, sterilized soil mix. Use tap water for cuttings.
Select Healthy Stems
In summer, collect healthy, leafy shoots, about 3–5 inches long, from plants that you have watered well the evening before. Take your cuttings in the morning, before the plants are stressed by high temperatures, and seal them in plastic bags to keep them fresh.
Take Off Lower Leaves
Pre-fill pots and trays with moist potting soil mix to avoid any delay once cuttings have been prepared. Using a sharp knife, cut just below a leaf joint and trim off lower leaves neatly to leave just two or three healthy ones at the top. Dip the cut ends in rooting hormone.
Push the cuttings into the soil mix, leaving the upper half exposed. Root singly in small pots or fit several into large pots or trays, making sure the leaves aren't touching. Firm lightly, water and cover with a clear plastic bag, or root in a propagator, and keep at 59–70 degrees F.