Hydrangea serrata Blue Billow
Hydrangea serrata Blue Billow

Hydrangea serrata Blue Billow

Shipment begins in Spring 2019

SKU: S63140
1 for $33.95
23 Reviews
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Quick Facts
Common Name: Mountain Hydrangea
Hardiness Zone: 5-9S/W Exposure: Sun to Shade
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Blooms In: Jul
Height: 4' Spacing: 5-6'
Read our Growing Guide Ships as: ONE GALLON POT
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Shipping Details Shipment begins in mid March 2019, depending on your zone. See shipping tab for details

Product Details

Product Details

The parents of this lovely Lacecap variety were found growing on the wooded slope of a Korean mountain, which explains its exceptional hardiness. It produces delicate clusters of light blue flowers that last for several weeks in early to midsummer (July here in Connecticut), turning a stunning deep crimson as they age. Fall foliage is an attractive shade of burgundy. Excellent in a shady border with Ferns and Astilbes. 'Blue Billow' is a reliable bloomer through Zone 6, and adventurous gardeners in Zone 5, where flowering occurs 3 or 4 years out of 5 may also wish to give it a try. It performed well at our nursery in full sun. Blooms on old wood.

Hydrangea is a valuable genus of some 100 species of shrubs and vines grown for their large and very showy flower heads. Hydrangeas are at their best in summer and fall—a quiet time for most woody plants—and are worth having for that reason alone.

For more information on Hydrangea care, click on Growing Guide.




The size of the plants we ship has been selected to reduce the shock of transplanting. For some, this means a large, bareroot crown. Others cannot travel bareroot or transplant best if grown in containers. We ship these perennials and annuals in 1 pint pots, except as noted. We must point out that many perennials will not bloom the first year after planting, but will the following year, amply rewarding your patience. We ship bulbs as dormant, bare bulbs, sometimes with some wood shavings or moss. Shrubs, Roses, vines, and other woody plants may be shipped bareroot or in pots. The size of the pot is noted in the quick facts for each item.


We ship our bulbs and plants at the right time for planting in your area, except as noted, with orders dispatched on a first-come, first-served basis by climate zone. Estimated dates for shipping are indicated in the Shipping Details box for each item. Please refer to the Shipping Details box to determine the earliest shipping time. Unless you specify otherwise, fertilizers, tools, and other non-plant items are shipped with your plants or bulbs. Please supply a street address for delivery. Kindly contact us with two weeks notice, if you'll be away at expected time of delivery.


We guarantee to ship plants that are in prime condition for growing. If your order is damaged or fails to meet your expectations, we will cheerfully replace or refund it. Please contact our Customer Service Department at 1-800-503-9624 or email us at [email protected]. Please include your order number or customer number when contacting us.



Average Customer Rating: (23 Reviews) Write a Review

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Hardiest Blue Hydrangea

J. Shaw from Cape Cod, Massachusetts

Hardy on Cape every year since I planted it 25 years ago - other hydrangeas have proved easily damaged in the winter. Be sure your soil is acid and if the blooms are not a superb blue, then add dust with sulfur in the late to make the soil more acidic.

1 of 1 people found this review helpful. Do you? yes no

Border Centerpiece

A viewer from Woburn, MA

My Blue Billow is 16+ years old and still going strong. It blooms a true shade of blue just in time for Independence Day in my area and is a show-stopper. I've had so many contractors, public works technicians, and neighbors ask me about it. Many are surprised to learn it's a Hydrangea since they're so accustomed to the puffball blooms. I've had landscapers whack the bejeebers out of it but it always comes back, big and strong. In fact, it seems to benefit from the occasional hard pruning. It keeps its shape better and prevents it from taking over the whole border planting. Mine gets strong morning sun but is in full shade from noon until sunset. No matter - it blooms like a sun-lover would. Get this shrub. You will love it!

4 of 4 people found this review helpful. Do you? yes no

No success

A viewer from NH

I had high hopes for this plant as I love blue and always looking for suitable perennials to add to this color in my gardens. Planted this in a border which receive some sun and shade. This was to be its second season and it is also it's last as it has died. Very disappointed, but as a gardener I know we don't always succeed. However it was expensive and I would like to know if anyone else in the northeast has had a similar experience.

1 of 1 people found this review helpful. Do you? yes no  Certified buyer

Gorgeous Lacecap

A viewer from MD

This plant takes several years to get established. However, it is worth waiting for. My plant is surrounded by bleeding hearts and shares space with a lavender azalea. It's neighbors are all done blooming for the year, but it is just coming into bloom (June 21 in central Maryland). A great plant to supply summer color to a shady garden.

1 of 1 people found this review helpful. Do you? yes no

WOW! Mail order was truth in advertising

Joy Miller from Assonet, Massachusetts, USA

Last spring I sent away for two of these from your company. They were packed nicely and on the small size but WOW in ONE YEAR did they grow, have tripled in size. Last year only one bloom, this year numerous blooms. Love the compact shrub type growing habit. Enough of this, lets talk flowers: the photos of the flowers do not do it justice, the parts in the middle and unopened parts are almost like a shiny type of fuzzy. Amazing. Am so very glad I took the chance and sent away for these. Will buy more as I am slowly adding various species of hydrangeas to my yard and want more of these. They are growing in poor soil, receive about four hours of direct sun from noon - 4pm Dappled sunlight in morning and shade after 4pm. They do NOT wilt like big headed ball varieties.

11 of 11 people found this review helpful. Do you? yes no  Certified buyer

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Growing guide

Growing guide

Latin Name Pronunciation: hye-dran'jee-uh 

Growing H. serrata

Light/Watering: Most varieties thrive in full sun in the North, but in the South require afternoon shade. Moist soils that do not dry out are best; do not plant in hot, dry, exposed sites. Mulch to conserve moisture and buffer soil temperatures.

Fertilizer/Soil and pH: In some varieties, flower color is determined by the pH of the soil; at low pH (acid soils) flowers will be blue and at higher pH, flowers will be pink. Generally, a pH below 5.0 results in deep, vivid blues and as the pH rises the flowers range from blue to lavender to mauve to a vivid deep pink at pH 7.0 (neutral). The pH determines the availability of aluminum in the soil; this element is more readily available in acid soils, and this availability results in the blue flower color. Since phosphorus ties up aluminum in soils, using a fertilizer low in this nutrient will aid in attaining blue flowers. If pink flowers are desired and your soil is acid, simply add lime to raise the pH and use a balanced fertilizer. Aluminum sulfate will lower pH if blue flowers are desired.

How to test your soil?

We recommend that you visit your local Cooperative Extension Service to find out about soil testing in your area. Follow this link for a directory of institutions involved in the Cooperative Extension program.

Pests/Diseases: None serious. Occasionally powdery mildew will infect the foliage, especially in humid areas with poor air circulation. Treat with an appropriate fungicide if the problem is serious, and be sure to rake up and destroy all fallen foliage in the autumn.

Pruning: Little pruning is needed, but if shrubs grow too large, cut back stems by about one-third by the end of August. In spring, only prune out dead wood. Most Hydrangea serrata varieties bloom on old wood. H. s. Tuff Stuff™ is a variety that blooms on both old and new wood. If no fall pruning was done, stems can be cut back by one-third in spring if necessary—but this will sacrifice the bloom on the old wood and shrubs will not flower until late summer.

Transplanting: Young plants may be transplanted when dormant in early spring; larger tree-form varieties are difficult to move once established, but it can be done. Prune top growth after transplanting to reduce water loss.

End of Season Care: Rake up and destroy any fallen foliage that was infected by powdery mildew or other fungi.

Calendar of Care

Early Spring: Prune out any dead wood from all varieties. Check soil pH and adjust up or down if needed for desired flower color. Feed plants with a fertilizer high in phosphorus (such as 15-30-15) to encourage blooms. Complete any transplanting before leaves unfurl.

Mid-Spring: Mulch plants after soil has warmed to conserve moisture and buffer soil temperatures. Watch for powdery mildew and treat as needed.

Summer: As soon as blooms fade, remove old flowering stems. If needed, prune as indicated above by the end of August.

Fall: Remove and destroy any fallen foliage that was infected by powdery mildew. If not pruned in spring, plants can be shortened, or pruned back to the ground.

For more information on growing Hydrangeas, click here.


What are the Various Types of Hydrangeas?
Pruning Hydrangeas
Why Didn't My Hydrangeas Bloom?
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