Phlox is an attractive blooming perennial bush which has the potential to grow very large and populate a vast area of space. For this reason, gardeners may wish to transplant their phlox to control its size or beautify another part of the yard with a particularly vivacious species. These step-by-step instructions will teach you how to successfully transplant your phlox, regardless of its size.
Step 1: Prepare the New Transplant Area for Planting
Before you begin dividing your existing Phlox, it is important to prepare the site where the divided plant will be placed in the ground. Choose a site that is appropriate for sustaining a Phlox; make sure that the soil is healthy and well drained. In addition, it is important to consider the amount of water and sunlight that is available in that area of your yard.
When you have determined where you want to plant your divided Phlox, dig a large hole into the ground. It should be at least 2 feet wide and 1 foot deep; you may deepen or widen the hole after you see the root system of the transplanted Phlox.
Step 2: Uproot and Clear the Roots of the Phlox
Phlox can be divided anytime during spring or summer even if the plant is in full bloom. This is true for all varieties except for creeping Phlox which is best divided and transplanted before or after bloom.
Use a strong shovel to clear a large trench around the roots of the phlox plant; dig deep enough into the soil to ensure that you can lift the roots out of the ground. It is not a bad idea to dig deeper than you think you have to, so you don’t have to dig deeper later. Use the tip of your shovel to completely uproot your phlox plant.
Once the roots are exposed, you can use your hands or a hose to loosen the soil that has invariably become entwined and caked onto the roots of the plant. Try to expose as much of the root system that you can without damaging the roots.
Step 3: Trim Unhealthy Roots and Divide the Plant
Once the root system is exposed, you may choose to divide the phlox plant into several separate entities. Use a sharp tool to cut the phlox into separate divisions, taking care to maintain a large root system for each of the divisions.
Once divided you can use a sharp pruning tool to trim back the roots and eradicate any unhealthy roots. Unhealthy roots are identified by their slimy or soggy appearance and texture as well as a deep yellow and brown color.
It is not a bad idea to eliminate about one third of each of the plant's root mass. This elimination simply frees up space for the plant to send off new and healthier roots.
Step 4: Transplant the Phlox or Phlox Divisions
Return to the area where you plan on transplanting the phlox; if necessary, deepen the hole so that it is just a bit deeper than the original root depth. Next, place the phlox plant in its hole taking care to spread out the roots. Fill the hole with soil before watering in the transplant; while watering you may notice that the plant needs more soil. Simply place more soil into the hole and water the plant until it is completely surrounded by soil.
Finally, cut off any blossoms that the phlox may have to divert energy down into the plant's root system.