Silver Spike Grass

Exclusive. Achnatherum calamagrostis (Silver Spike Grass) is an outstanding Old World species grown for its late spring display of silver-green flower spikes. The seed heads age to tawny brown and hold on the plant into the fall. Drought Resistant/xeric. Introduced into cultivation in the US by Lauren Springer Ogden. 2006 Plant of the Year.
Zones5 - 8
Easy To Grow
Light Requirements
Full Sun
Water Tolerance
Mature Height 36" tall
Mature Spread36" wide
Shipping DetailsNo longer available this season. Learn More…

USDA Hardiness Planting Zones

To determine if a plant is sufficiently cold hardy, the USDA created numbered zones indicating winter low temperatures; the lower the zone number the colder the winter.

  • If the coldest winter temperature expected in your area is -15°F (zone 5) then any plants rated zones 3-5 will survive the winter temperatures in your area.
  • If you live in very warm winter areas (zones 9-11) plants with zones 3-4 ratings are not recommended. The lack of freezing winter temperatures do not provide a time for winter dormancy (rest).

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A spectacular European native, Achnatherum calamagrostis (Silver Spike Grass) is both a graceful and free-flowering summer blooming ornamental grass. It will beautify your garden with its showy, silver-green flowering spikes that turn a rich tawny brown in the fall. For best garden performance Silver Spike Grass should be grown in the western US (and other higher altitude areas of the country) where summer humidity is low and nights are cool. Seed of this grass comes to us by way of Lauren Springer Ogden, who has pioneered the use of it in this country by successfully cultivating it in CO for over 8 years. Achnatherum is sure to be extremely popular as it is a distinctive, specimen-worthy species with highly visible areas of your landscape.  Flat of 9 plants will cover 30 square feet when planted together. 36" tall x 36" wide (seed/division propagated). 2006 Plant of the Year.
More Information
Associated SKUsHC016081
HC013923 (Plant - 5" Deep Pot) - Out of stock.
HC015642 (Tray of 9) - Out of stock.
Common Name
Silver Spike Grass
Botanical Name
Achnatherum calamagrostis
5, 6, 7, 8
Light Requirements
Full Sun
Mature Height
36" tall
Mature Spread
36" wide
Ships As
Potted Plant
Soil Type
Average Soil, Sandy Soil, Clay Soil
Soil Moisture
Easy To Grow
Perennial Plant of the Year
Special Groups
High Country Gardens Exclusive, High Country Gardens Introduction
Ideal Region
West, Western Only, Pacific Northwest, Suitable Above 7000 ft
Planting Time
Spring / Summer, Fall
Neonicotinoid Free
Ships To Canada
Planting Guides

View more Planting Guides, or download our complete Planting Guide for tips on caring for your plants when you receive your order, as well as planting instructions for Perennials, Spring-Planted Bulbs, Fall-Planted Bulbs, Cacti & Succulents, Xeric Plants and more.

No longer available this season.

As soon as your order is placed you will receive a confirmation email. You will receive a second email the day your order ships telling you how it has been sent. Some perennials are shipped as potted plants, some as perennial roots packed in peat.  The ‘Plant Information’ section describes how that item will ship. All perennials and spring-planted bulbs are packaged to withstand shipping and are fully-guaranteed. Please open upon receipt and follow the instructions included.

Perennials and spring-planted bulbs are shipped at the proper planting time for your hardiness zone. Perennial and spring-planted bulb orders will arrive separately from seeds. If your order requires more than one shipment and all items are shipping to the same address, there is no additional shipping charge. See our shipping information page for approximate ship dates and more detailed information. If you have any questions, please call Customer Service toll-free at (800) 925-9387 or contact us by email.

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US Shipping Charges

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$75 to $99.99$16.99
$100 and Over$18.99

Canadian Shipping Charges

Merchandise Shipping
Up to $24.99$14.95
$25 to $49.99$19.95
$50 to $74.99$24.95
$75 to $99.99$29.95
$100 and Over$39.95

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