I need to move my 2 year old butterfly bush to a location that has more space.
What is the best way to transplant? What time of year should I attempt this? TY
Thank you for contacting the Toronto Master Gardeners about your butterfly bush (buddleia davidii) transplant plans. After only two years, your plant seems happy, so congratulations. Before suggesting how you might keep it to a small and controlled size, let’s answer your question about transplanting.
Because it blooms on new wood, it is best transplanted prior to spring growth or in the fall once the foliage has become dormant. Moisten the soil before digging the clump, separate sections of roots and shoots and replant in the new location making sure you do not plant it any deeper than it was in the other location.
While not considered invasive in Ontario, butterfly bush spreads quickly, as you have already discovered, and must be controlled. Deadheading helps to prevent it from seeding all over the place (do not compost the dead flowers). When choosing a new location for your bush (sunny, not windy, moist and well draining soil), please make sure it is kept well away from open, natural, ravines or environmentally sensitive areas into which it can escape – monitor, deadhead and prune regularly to keep it under control.
In case you are looking for an alternative plant without this worry, below is a link to the Ontario Invasive Plant Council’s excellent brochure on plant substitutes.
.https://www.ontarioinvasiveplants.ca/wp-content/uploads/2020/04/Southern-Grow-Me-Instead-1.pdf
Another option to save you the hard work of transplanting this bush to another location, would be to leave your plant where it is but continuously deadhead the flowers and prune it back hard each spring before new growth appears. Doing this may allow you to keep the shrub at a smaller more manageable size and save yourself all that digging.
Hope this information is helpful.