Perennials that grow from bulbs, tubers, corms, or other underground storage organs are all easy to divide. Some may not produce flowers well for a year or two after you divide them, but most bulbs recover quickly and multiply fast enough to make dividing a good idea. Examples of these types of bulbs would be daffodils, crocuses, meadow saffrons, grape hyacinths, bluebells, snowdrops, species tulips, ornamental onions and Asiatic hybrid lilies.
- Dig around the edge of the clump as deep as possible to loosen the soil.
- Lift the whole clump and shake off the extra soil.
- Pick the plants apart leaving the roots and leaves attached.
- Discard any plants that are bruised or damaged.
- Replant the bulbs individually, burying them as deep as they were before you dug them up.
Astilbes are an example of a perennial that has very dense clumps of foliage and flower stalks with equally dense roots. The crown is usually so tight and tough that you will need a sharp tool to split it into three or four divisions. Tough clumps include goatsbeard, lady’s mantle, Joe Pye weed, false sunflower, purple loosestrife and most sages and salvias. The toughest of all are the ornamental grasses such as Japanese silver grass.
- Dig a circle around the edges at least three times as wide as the crown of the plant.
- Pry underneath with your tool and lift the whole clump up.
- Shake off some of the soil, or use a hose. Use a sharp tool to cut equal sections, severing between the major shoots or buds, cutting right through any knots.
- Replant, always keeping the top of the crown level with the soil.
Check back for how to divide perennials that spread in clumps, mats and patches!