Butterfly Bush Buddleja davidii Purple Emperor = 'Pyrkeep' (English Butterfly Series)

Water

The Butterfly Bush should be watered deeply to encourage root growth, with around 1-2 gallons per week for established plants, depending on weather conditions and soil type. Newly planted Butterfly Bushes require more frequent watering to help them settle in, which might mean watering them every other day for the first few weeks, then gradually reducing the frequency as they establish. Ensure the soil is well-draining to prevent root rot and water early in the morning to reduce evaporation losses. During hot, dry spells, additional water may be necessary, but always check the soil moisture first to avoid overwatering.

Light

The Butterfly Bush thrives best in full sun, meaning it requires at least 6 to 8 hours of direct sunlight each day. Planting it in a spot where it can receive unfiltered sunlight during the majority of the day will ensure optimal growth and flowering. It can tolerate some light shade but flowering may be reduced in less than full sun conditions.

Temperature

The Butterfly Bush is hardy and can withstand a range of temperatures, thriving best when the temperature is between 60 and 85 degrees Fahrenheit. It can survive minimum temperatures down to around -20 degrees Fahrenheit, but the ideal is to keep it within the optimal range for vigorous growth and blooming.

Pruning

Prune the Butterfly Bush in late winter or early spring to encourage new growth and flower production. Cutting back by about one-third to one-half can improve the plant’s shape and vigor. Additionally, deadheading throughout the blooming season encourages more blooms and prevents the plant from becoming too leggy.

Cleaning

As needed

Soil

The Butterfly Bush (Buddleja davidii) thrives in well-drained soil enriched with organic matter, with a pH range between 6.0 and 7.0. A good soil mix would consist of loamy garden soil, compost, and peat with a layer of mulch to retain moisture.

Repotting

Butterfly Bush does not typically require frequent repotting as it is mostly grown as a garden shrub; however, if kept in a container, repot every 2-3 years or when rootbound.

Humidity & Misting

The Butterfly Bush prefers outdoor humidity conditions and does not require specific humidity levels. It is quite adaptable to the ambient humidity found in most temperate regions.

Suitable locations

• Indoor

  Grow in bright light, prune to shape, keep soil lightly moist.

• Outdoor

  Plant in full sun, provide space for growth, well-draining soil.

• Hardiness zone

  5-9 USDA

Life cycle

Buddleja davidii 'Pyrkeep', commonly known as Butterfly Bush Purple Emperor, starts its life as a seed, which, once in favorable conditions—well-draining soil and full sun—will germinate within two to three weeks. The seedling stage follows, which is characterized by the growth of the plant's initial leaves and root system. It then enters the vegetative stage, where it focuses on developing a sturdy stem and a fuller spread of foliage. This is followed by the flowering stage, typically in summer through to fall, where the plant blooms with cone-shaped clusters of purple flowers that attract butterflies and other pollinators. After pollination, seeds are produced, which are dispersed when the flowers die back at the end of the growing season. The plant may enter a dormancy period in colder climates during the winter or continue its growth in milder regions, completing its perennial cycle.

Propogation

• Propogation time

  Spring-Early Summer

• Propogation: The Butterfly Bush 'Purple Emperor' can be most commonly propagated through semi-hardwood cuttings. This method is often carried out in late summer, after flowering has occurred. To undertake this process, one selects a healthy, non-flowering shoot and cuts a piece about 4 to 6 inches (10 to 15 cm) long, just below a leaf node. The lower leaves are then removed, and the cut end is dipped in rooting hormone to encourage root development. The cutting is then placed in a well-draining potting mix and kept moist. It should be placed in indirect light until roots have developed, at which point it can be transplanted into the garden or a larger pot.