Firefly Hydrangea

Hydrangea macrophylla 'Horcos' (PP# 27,110)

Firefly Hydrangea

Hydrangea macrophylla 'Horcos' (PP# 27,110)

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How are the heights measured?

All tree, and nothin' but the tree! We measure from the top of the soil to the top of the tree; the height of the container or the root system is never included in our measurements.

What is a gallon container?

Nursery containers come in a variety of different sizes, and old-school nursery slang has stuck. While the industry-standard terminology is to call the sizes "Gallon Containers", that doesn't exactly translate to the traditional liquid "gallon" size we think of. You'll find we carry young 1-gallons, up to more mature 7-gallons ranging anywhere from 6 inches to 6ft.

How does the delivery process work?

All of our orders ship via FedEx Ground! Once your order is placed online, our magic elves get right to work picking, staging, boxing and shipping your trees. Orders typically ship out within 2 business days. You will receive email notifications along the way on the progress of your order, as well as tracking information to track your plants all the way to their new home!

Why are some states excluded from shipping?

The short & sweet answer is: "United States Department of Agriculture Restrictions." Every state has their own unique USDA restrictions on which plants they allow to come into their state. While we wish we could serve everyone, it's for the safety of native species and helps prevent the spread of invasive disease & pests. We've gotta protect good ole' Mother Nature, after all.

About Me


The Firefly Hydrangea is a compact new variety of mop-head hydrangea that forms a bush between 4 and 5 feet tall and wide – perfect for edging a path or in the foreground or larger beds. It is repeat-blooming, carrying flowers from late spring into early fall, with every head lasting 6 weeks or more. The blooms are pale yellow with bold deep-pink edges, making a beautiful bi-color display. The large flowers have petals that wrap around each other forming a fluted cup. Bring this sparkling beauty into your garden and let it set fire to your summer beds, or grow it in a planter or pot.

  • Striking bi-color flowers in pale yellow and deep-pink
  • Continuous blooming from late spring into fall
  • Compact form for smaller beds and pot-growing
  • Grows well in partially-shaded areas
  • Reliable and easy to grow

To have a good flower display you should plant the Firefly Hydrangea in light or partial shade, with some direct sun in the mornings if possible. Grow it in rich, moist, well-drained soil. Water and fertilize regularly for good results, as this plant isn’t drought resistant. Prune lightly in late summer, removing spent flower heads back to the first strong buds. It is normally free of any significant pests or diseases.

Plant Hardiness Zones 6-9
Mature Width 4-5
Mature Height 4-5
Sun Needs Partial Sun
Zones 6-9

Gone are the days when hydrangeas bloomed just once a year. Today continuous blooming from late spring to fall has become normal, and that’s exactly what you get with the Firefly Hydrangea. As soon as your spring shrubs begin to finish, the first blooms of this gorgeous new variety will be opening. Each head is attractive for at least 6 weeks, and as new stems grow up they too burst into bloom, so that you have a wonderful and continuous display of fresh blooms all the way into early fall. Just as those golden fireflies glimmer in the dusk, so the golden centers of the lovely fluted flowers of this compact shrub will glimmer and glow in your garden. Each bloom looks hand-painted, with a pale yellow center surrounded by a broad pink band – it could be made of porcelain. The large heads top a rounded, compact bush with rich-green leaves that’s perfect for your garden or in pots. What more is there to say? To see it is to love it.

Growing the Firefly Hydrangea

Size and Appearance

The Firefly Hydrangea is a compact deciduous shrub, typically 4 feet tall and wide, but perhaps a little taller in warm zones. It is fast-growing, soon filling out and putting on a gorgeous display. The large oval leaves – almost 5 inches long – have a slightly leathery, glossy texture with a puckered surface, and bold serrations along the edges. The new leaves are burgundy red, turning deep, rich green as they mature. Even without flowers this would be a valuable foliage plant, and looks so fresh and bold through the spring. Soon, at the tips of every new shoot, you will see a small greenish cluster developing. This quickly expands into a pale-green cluster of flower buds, with the first opening by late spring. As more stems grow up during summer, more buds develop, making this a perpetual-blooming shrub. Fresh flower heads will still be opening in late summer, looking good into the fall.

The flower buds open into a dome-shaped flower head 6 to 7 inches across, carrying well over 100 individual flowers. Each bloom is 2 inches across, with 4 or 5 petals that are so broad and full they form a spiraling whorl, giving this flower a very full look. Each petal is pale yellow – stronger yellow when first opening – edged with a broad band of deep pink. The overall look is bi-color, and totally charming. In alkaline soils, the coloring may be more purple.

Using the Firefly Hydrangea in Your Garden

The compact form of the Firefly Hydrangea makes it perfect for edging beds or growing along a pathway. Plant it beneath large trees to brighten the more shady parts of your garden. Its fresh look is just as beautiful around an older-style home as it is in a modern, city-garden setting. It is also perfect for pots and planters, decorating a shaded terrace, on a porch or greeting you as you reach the front door.


The Firefly Hydrangea grows best, and blooms most continuously, in warmer areas, from zone 6 into zone 9 or even zone 10.

Sun Exposure and Soil Conditions

Although hydrangeas are often suggested for shade, they don’t bloom well if there is too much of it. The ideal spot is bright, perhaps with morning sun, but shaded in the afternoon. The bright shade beneath tall trees, or along the foot of a north-facing wall is often also good, but avoid areas with heavy, dense shade. The soil should be rich and moist, but well-drained. Plenty of richer organic materials when planting, and as regular mulch, make a huge difference, and water regularly too. For drier or more sunny conditions we recommend panicle or oak-leaf hydrangeas. The best pink coloring will develop in acidic soils.

Maintenance and Pruning

The Firefly Hydrangea is usually free of pests or diseases and grows best with attention to regular watering, especially during the summer months. Use fertilizers designed for pink hydrangeas, or any fertilizer for acid-loving shrubs, for the best results. This is especially necessary when growing in pots, where regular feeding and using potting soil for acid-loving plants is important. The little extra attention needed will be rewarded many times over with the fabulous results you will see.

Little pruning is needed, and this should be done in mid-summer. Remove spent flower heads back to the first strong pair of buds – these are next year’s flowers. Older plants can have up to one-third of their branches removed to encourage new stems to sprout from the base – look for old, weak branches that are not flowering well. Don’t over-prune, don’t cut back hard to the ground, and never trim new stems as they are growing.

History and Origin of the Firefly Hydrangea

Mophead hydrangeas, Hydrangea macrophylla, caused a sensation when they first arrived in Europe from Japan, and they have been incredibly popular garden plants ever since then – over 150 years ago. Wild plants have tiny, seed-producing (fertile) flowers – you can see a few hidden among the blooms of the Firefly Hydrangea. Most of the blooms, though, are sterile, without seeds, and these plants are called ‘hortensia’ when they have these large heads and large florets. Europe has always been a big center for growing and breeding hydrangeas, and that is where the Firefly Hydrangea was created.

Katrin Meinl is one of the growing number of professional plant breeders, working in Dresden, Germany, for the Küehne Jungpflanzen nursery. In 2004, as part of her work breeding hydrangeas she took pollen from one of her own seedlings and used it to cross-pollinate an older variety called ‘Selma’. In 2006 she selected a plant from among the seedlings and named it ‘Horcos’. In 2014 Katrin and the nursery received European Plant Breeder’s Rights on her plant, and in 2016 she was granted a plant patent in the USA. Her plant is released in America by Star® Roses and Plants with the common name Firefly. This mophead hydrangea should not be confused with a variegated climbing hydrangea (Hydrangea anomala subsp. petiolaris) called ‘Firefly’.

Buying the Firefly Hydrangea at the Tree Center

It is impossible to have too many hydrangeas in your summer garden, and for brightness and unique coloring, you can’t beat the superb blooms of the Firefly Hydrangea. We always try to keep up with the latest and the best, and our regular customers can quickly take all our stock of exciting new plants like this one. Order now – they will all be gone very soon.

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Firefly Hydrangea

Hydrangea macrophylla 'Horcos' (PP# 27,110)