Generally speaking, winter is the best time to transplant anything in my area, but maybe in Ohio, spring would be better. If your butterfly bush isn't too big, and you can dig it up without damaging too many roots, then I'd think it'd work fine to move it now. If you break roots, then you should cut the top back some, too.
Sherry

Yes, you can move it now in our colder zones. I would try to get as large a rootball as possible, with as much soil as possible, then keep well-watered.

I have moved several of these in the past, and they survive just fine, but the growth will be set back some. They grow best when allowed to establish in one spot for several years.

If you transplant it now, it will require a lot more attention than if you move it in fall or early spring. Now is getting close to the very worst time to move it because it will not have time to become well established before the most stressful time of year for the plant (hot summer weather). If you do move it now:

1. Dig as large of a rootball as is reasonably possible. Moving your shrub with a larger rootball will increase the likelihood of success. Here is my generic rootball guide, but I would use it as an absolute minimum when moving a tree or shrub this time of year:
For trunk diameter below 1/2", multiply the diameter by 20 to get approximate rootball diameter.
For trunk diameter between 1/2" and 1", multiply the diameter by 18 to get approximate rootball diameter.
For trunk diameter between 1" and 1-1/2", multiply the diameter by 16 to get approximate rootball diameter.
For trunk diameter between 1-1/2" and 2-1/2", multiply the diameter by 14 to get approximate rootball diameter.
For trunk diameter between 2-1/2" and 4", multiply the diameter by 12 to get approximate rootball diameter.
Here are guidelines for rootball depth:
For a rootball with a diameter of 1', depth should be approximately 8".
For a rootball with a diameter of 2', depth should be approximately 1'.
For a rootball with a diameter of 3', depth should be approximately 15".
For a rootball with a diameter of 4', depth should be approximately 18".

2. Keep a careful eye out for watering needs. Check the surrounding soil and the rootball (if the soil types are different) on a regular basis. The soil surface should be allowed to dry in between waterings, but the soil at an inch or so below the surface should not. Also remember that slow, deep watering when needed is much better than frequent, quick, shallow watering.

3. Mulch well. A layer of organic mulch 2" to 4" thick (depending on the material) and with as large of a diameter as reasonable (but at least out to the dripline) should be used. Remember mulch wide, not deep. Also leave an inch or so between the trunk and where the mulch starts. Never pile mulch up against the trunk. Applied properly, mulch:
-improves soil fertility and texture as it breaks down,
-prevents germination of many weed seeds,
-reduces competition for food and water from grass and weeds,
-reduces erosion,
-helps to maintain soil moisture during dry periods,
-often aids drainage by preventing surface crusting and sealing,
-can keep roots cooler during hot summer weather,
-can help to moderate soil temperature fluctuations,
-reduces frost-heaving,
-reduces certain soil-borne diseases by preventing soil and fungi from splashing onto foliage,
-prevents damage from mowers and trimmers,
-and improves the look of the landscape.

4. Prune as little as possible until the shrub starts to become established. Root regrowth will be directly dependent upon amount of material above ground. Cutting back at planting may help a severely stressed plant for a day or two, but, in the long run, will directly increase the time it takes the plant to recover and, in most cases, lesson its overall chances of success.

Here is a link that might be useful: Planting a Tree or Shrub

Have you thought about taking a cutting and rooting it and starting over? Buddleia roots very easily.

Sandy

What do I need to do to get my bushes to bloom? They are several years old and have never bloomed.