Introduction

Buddleia davidii, commonly known as the butterfly bush or summer lilac, could be a gorgeous addition to any landscape or garden. The first Buddleia species discovered was actually a tropical variety from the Caribbean Islands around the 1730s. Today’s more widely grown species did not start being used until the late 1800s and is native to central China. Buddleia species can be as tall as 6 to 16 feet typically; however, some species are nearly 80 foot tall trees. Dwarf varieties are also available to the public, only growing to be about 3 feet tall. It is important to note that the butterfly bush is considered an invasive species depending on the specific species and location it is being grown in. Please, find out this information based on the variety you would like to use and your location prior to propagating or growing this plant.

This woody shrub is know to grow quickly and to possess fragrant flowers that come in a variety of colors (white, orange, pink, blue, etc.). There are many species of butterfly bush, and many more are being created through the efforts of plant breeding. These plants are also known to be quite durable. Few pests or pathogens are known to greatly affect butterfly bushes, unless, of course, stressful conditions are presented. The plant also will flower again every year, sometimes losing its extremely vibrant color with age. As described by its common name, this shrub is known to attract butterflies (like the Painted Lady and Monarch), as well as a variety of other local pollinators (including bees, moths, and occasionally birds like the hummingbird and even orioles).

These plants prefer full sun for optimal growth and should be placed in locations where people will be able to smell their fragrant aroma during the summer blooming months. These plants are even well suited for city-life, seeing as they appear to withstand pollution quite well. The Buddleia davidii is suited for USDA Hardiness Zones 5 to 10, making them good for outdoor gardens. However, some bred and wild are best for only zones 7 or 8. These tough plants can withstand low nutrient and alkaline soils but do need an average, well drained garden soil to avoid rotting. These amazing garden plants are even drought tolerant. If grown indoors, daily waterings are needed; however, if outdoors, supplemental waterings should not be necessary (only once every few weeks during dry periods). Another tip for keeping a healthy butterfly bush is to prune yearly, thus avoiding their stem’s tendency to split with age.

Many methods can be used to propagate the butterfly bush. These methods include, sowing the collected and dried seed heads from an established bush, dividing a healthy, already established bush, or with cuttings. Other methods of propagation, like tissue culture, are not typically used to propagate the butterfly bush. Methods like tissue culture are much to expensive to be worth using on a plant that is much more easily and cheaply propagated by other means.

For the purpose of this blog post, we will be focusing solely on the instructions and tips for cutting propagation of the butterfly bush.

How-To

General Supplies:

• Sterilized Sharp Tool (pruning shears, blade of some sort, etc. … the sterilization (bleach, heat treated, etc.) avoids the spread of disease)
• Water
• Potting Mixture (equal parts peat moss and perlite)
• Container (pot, etc. … must holes on the bottom for drainage)
• Saran Wrap (if a greenhouse is not available)
• Spray Bottle (if a greenhouse with a mist system is not available)
• Rooting Hormone (optional)

The Stock Plant:

Take your cutting from a healthy (vibrant colors, not visibly diseased or infested, etc.), well-developed butterfly bush plant. Pick a plant that is of the flower color/variety you desire, seeing as the propagation you are about to do is essentially a clone of that plant. Avoid plants that appear to have diseases, pests, and pathogens. The healthier the chosen stock plant, the more likely the success of the rooting of the cutting you are about to take.

The Cutting:

The cuttings taken from this plant are considered softwood cuttings (the succulent new growth that is not yet woody). These easy to root cuttings should be taken in the summer time (between May and July). With your sheers/sharp tool take a stem on the upper portion on the plant, avoiding the flower buds as much as possible. Be sure to pick a healthy looking stem (vibrant color, minimal to no wilting or present disease, etc.). Cut your chosen stem to about 4 to 6 inches long, be sure to cut just below a healthy bud (as depicted in Figure 2). Remove the leaves from the lower 1/3 of your cutting.

Rooting Hormone:

For a faster rooted cutting, rooting hormone ( auxin) can be placed on the lower 1/3 of your cutting (the end you cut and that will be placed in your potting mixture). This rooting hormone will also increase the chances of your cutting taking root. Dip that lower 1/3 of your cutting into IBA (a form of the rooting hormone) powder that is between 3000 and 8000 ppm. Before placing your cutting into the potting mixture, tap off any excess IBA powder.

Potting and Media:

Thoroughly mix up a potting mixture of equal parts moistened peat moss and perlite. The mixture should be moist but not drowning. Fill your container with holes with your potting mixture. Place that lower 1/3 section (with or without hormone on it) into the potting mixture you prepared (with the area of the removed leaves and lower buds submerged).

Care:

Keep the potting mixture moist (but not drowning) and be sure to place the plant in bright (but indirect) sunlight. To keep the plant from drying out while it is rooting, lightly cover the plant with saran wrap (even a plastic baggie or plastic grocery bag would work) and mist it regularly.

Transplanting:

After about 3 to 6 weeks, the cutting will have developed roots. If you are not sure that your cutting has rooted, lightly tug on the stem. If you are presented with resistance, then your cutting has rooted. You can then either place the plant in a bigger container or out in your garden.

Conclusion

The butterfly bush is a beautiful addition to any garden, landscape, and even home. It is extremely easy to propagate this durable shrub as long as the requirements (not invasive in your area, proper stock plant, etc.) are met and the steps above are followed. Have fun trying cutting propagation out for yourself and enjoy your very own butterfly bush!

Works Cited

Hartmann, Hudson Thomas. “10: Techniques of Propagation by Cuttings.” Hartmann & Kester’s Plant Propagation: Principles and Practices. Upper Saddle River, NJ: Prentice Hall/Pearson, 2011. 345+. Print.

http://www.mastergardeners-rc.org/butterfly-bush-prop.html

Owen, D.F. and Whiteway W.R. (2003), Buddleia davidii in Britain: History and development of an associated fauna, Biological Conservation, 17(2), Pp. 149-155

http://www.plantdelights.com/Article/Buddleia-Butterfly-Bush

http://voices.yahoo.com/propagation-butterfly-bush-5358759.html?cat=30