This post will explain how we go about turning the larger type of butterfly bush, Buddleia davidii, not the dwarf or smaller types that are now available, into a standard. By a standard I mean a woody shrub that normally grows with several stems at ground level that has been pruned and trained into a single stem supported by a strong post with branching at a higher level.
There are lots of reasons to do such a thing, including using the space underneath to grow more plants, manage a shrub that can get quite large and unruly in a small garden, it offers a neater appearance, it’s fun to do and the best reason of all, the butterflies!
Right up front I want to mention that often an especially harsh winter, even in USDA Zone 7a southeast Tennessee, will kill the upper parts of Buddleia davidii back to the roots, especially on older standards. But not to worry, for the gardener can start the process all over again with the young shoots that regrow, sometimes, often actually even improving on the shape and size. We don’t always get multiple chances to get pruning right but this dying back can be a blessing as we are continually evolving in skill level with the secaturs. Above is B. ‘Potter’s Purple’ in its fifth incarnation as a standard.
Experience has taught me it is better to begin the branching low enough so that the flower ends are easier to photograph. In the past, photo from August of 2010, the flowers and the flutterbies they attract were sky high!
Choose a young, healthy and vigorous cultivar of butterfly bush. B. ‘Pink Delight’ and B. ‘Potter’s Purple’ are two good selections that have been growing in the Fairegarden as standards for over twelve years now. In some places Buddleia davidii is considered an invasive pest, but in my garden that is not the case. The few unwanted seedlings that have appeared here are easily pulled and composted, but a couple were stuck behind the arborvitae hedge to help hide the brush pile and offer sustenance to critters. The photos illustrating the technique for this post were executed on one of those strays. We have also rooted prunings by simply sticking them in the ground. The opening photo is of a cutting grown standard of B. ‘Potter’s Purple’ flanked by red Asiatic lilies. The above photo is the mother B. ‘Potter’s Purple’ in August of 2010.
Pick a sunny and well drained spot in which to plant a new subject, or use this method on an established bush. I have done it both ways with success. You will need a strong metal stake, rust proof wire and scissors or snips to cut the wire and sharp pruning shears. Don’t dull your good pruners by cutting wire with them!
Let us begin. This is a two year old seedling, one of three planted in a cluster to hide the brush pile at the back of the property. Any of these stems could be used to become the single trunk, but we are going to select the older, more woody one for this purpose. It will be stronger and less likely to break off with the manipulation involved in securing it to the metal stake. All other stems will be cut away below ground level. Vigilence is needed to continue cutting away any stems trying to grow from the roots or along the trunk.
Cut off all of the lower branches flush with the main stem. When there are two or more branches of nearly equal thickness, choose to leave the one that will make the straightest trunk, even if it is not the thickest.
Insert the metal stake. This is a five foot fence post. A filled out Buddleia in full bloom is heavy, especially when wet. The main trunk can break under the weight, especially in high winds or storms. The prop needs to be up to the task, so please don’t use bamboo or small diameter metal for this job.
Secure the stem to the metal stake with rust proof wire in as many places as needed to straighten the trunk. Be gentle and go slow, you don’t want to damage this stem, it will be the main artery for abundant blooms and foliage growth for several years. Its health and well being are what makes this project successfull, but if it does break, wait a while for new growth and try again later. As with all staking, including dahlias, lilies or whatever, first tie the wire to the stake, give it a couple of twists then tie the branch with a few more twists. Be prepared to check and loosen the latter twists so the metal does not dig into the bark over the years. An inch or two or three for leeway should restrict the movement enough to prevent breakage without cutting into the stem. Pruning is a constant to maintain these and all standards. Buddleia davidii is an excellent choice to be so grown because it blooms on new growth. The more you cut, the more flowers you get. In winter here the stems are cut to about six inches from the branching point.
An earlier post was written about the butterly bush standards in July of 2008 that can be seen by clicking here. As with all of the old posts written on the blogger platform, before the switch to WordPress on September 10, 2008, the photos are small but clickable to enlarge.
For other posts written by Fairegarden, look for How To on the sidebar page listing or click here.