Hydrangea serrata 'Blue Billow'
Hydrangea serrata 'Blue Billow'

Hydrangea serrata 'Blue Billow'

SKU: S63140
1 for $38.00
Quick Facts
Common Name: Mountain Hydrangea
Hardiness Zone: 5-9S/W Exposure: Sun to Shade
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Blooms In: Jul
Mature Height: 4' Spacing: 5-6'
Read our Growing Guide Ships as: ONE GALLON POT
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Shipping Details Shipment begins in late March 2023, depending on your zone. See shipping tab for details
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Product Details

Product Details

The parents of this lovely Hydrangea serrata (Lacecap) variety were found growing on the wooded slope of a Korean mountain, which explains Blue Billow's exceptional hardiness. This shrub 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.

For this Hydrangea, you can change the color of your blooms by using one of our soil additives, flowers will generally be more blue when grown in acid soils, and pink when grown in alkaline soils.

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. We also ship a wide range of containers and planters, tools, supplies, fertilizers, garden wear, garden decor items, as well as indoor decorations like wreaths and dried bouquets when available. Estimated dates for shipping are indicated in the green Shipping Details box for each item. Please supply a street address for delivery. Kindly contact us with two weeks notice, if you'll be away at the 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: 4 out of 5 stars (28 Reviews) Write a Review

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Beautiful Blue

I purchased one Blue Billow from WFF 18 years ago. Since then it has grown and spread into a 4ft high 12 ft long hedge - all on its own! Paniculatas may be basking in all the attention, but I adore this beautiful blue (yes, really blue!), well behaved, tough as nails shrub. And the bees love it as much as I do. Zone 6, west side of house, sun/shade.

5 of 5 people found this review helpful. Do you? yes no

It got bigger than expected

I bought the “blue billow “ hydrangea from white flower farm many yrs ago and it has grown hugh and outgrown its space. It is much bigger that anticipated or originally listed measurements and that is without any fertilizer!
Now I will pull it out and toss it. Sorry I planted it.

3 of 15 people found this review helpful. Do you? yes no

Bees love Blue Billows

Love this Hydrangea because the bees absolutely love it! I am in zone 4-5, but it is in a sheltered area under large Burr Oaks, it does not get much sun. It does take some patience and pampering to get established. I made the mistake of having to move it several times, so I really set it back. However it was worth the wait. I purchased a second last year. My advice find a spot and try not to move it.

16 of 16 people found this review helpful. Do you? yes no  Certified buyer


Bought the first because of a shady spot and ended up buying two more the next year. Lots of blooms and as it gets bigger and more established, there are more blooms and the color is deeper and brighter. We are zone 5. Love ❤️ this plant!!!!

74 of 75 people found this review helpful. Do you? yes no

Trust WFF

I moved to Washington DC when I had just turned 60, and didn't have the patience to start a garden from scratch again...but when I couldn't find a blue billow at a nursery, I reluctantly ordered a tiny one from WFF. Meanwhile, my landscape guy found a much bigger one at a very reputable nursery, so I planted it in the "plum" spot, and stuck the WFF babykin under a bunch of other random old plants and ignored it. I assumed it would die, but guess what, it took a few years, but the little WFF blue billow emerged from the underbrush and now looks spectacular, while the nursery plant looks "blah." Makes me laugh at myself every time I look at the two of them...suffice it to say you get what you pay for when you buy a plant from WFF...just have patience!

90 of 91 people found this review helpful. Do you? yes no

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Growing guide

Growing guide
Print Grow 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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