San Marcos GrowersSan Marcos Growers
New User?
Wholesale Login
Enter Password
Home Products Purchase Gardens About Us Resources Contact Us
Search Utilities
Plant Database
Search by Plant Name
Advanced Search
Search by size, origins,
color, cultural needs, etc.
Website Search
Search for any word
Site Map
Retail Locator
Plant Listings

PLANT TYPE
PLANT GEOGRAPHY
PLANT INDEX
ALL PLANT LIST
PLANT IMAGE INDEX
PLANT INTROS
SPECIALTY CROPS
NEW  2020 PLANTS

PRIME LIST
  for OCTOBER


 Weather Station

 
Products > Helianthus giganteus
 
Helianthus giganteus - Giant Sunflower
   

 
Habit and Cultural Information
Category: Perennial
Family: Asteraceae (Sunflowers)
Origin: North America
Flower Color: Yellow
Bloomtime: Fall
Height: 6-8 feet
Width: 6-8 feet
Exposure: Full Sun
Irrigation (H2O Info): Medium Water Needs
Winter Hardiness: < 0 F
Helianthus giganteus (Giant Sunflower) - A native American herbaceous perennial that produces a several unbranched to few branched slightly hairy reddish square stems up to 8 feet tall that arise from the rhizomatous and spreading base and hold 3 to 5 inch long narrow lanceolate green leaves that undulate slightly with crenate margins. In late summer appear the small 3 inch wide bright yellow sunflowers consisting of 10-20 yellow rays and held in loose clusters at the branch ends. In fall as the flowers fade the drying seed heads are interestingly attractive. Plant is full sun to light shade and give little to regular irrigation - the more you water the bigger it gets. Cut to the ground in late fall or early winter. Hardy into zone 4 (<-20). This wild plant is attractive and fun in the garden. It stays fairly constrained in gardens that are kept fairly dry but where is gets regular irrigation it can be fairly aggressive and spreading, so in irrigated gardens is best where it has room to roam in the back of a border or deep in the meadow. This plant is native to the eastern United States and eastern and central Canada, from Newfoundland west to Alberta south to Minnesota, Mississippi, and South Carolina where it typically is found in valley bottoms in moist soil or wet meadows. We received this plant from John Greenlee and it has grown in our garden for several years - all who see it in the fall are impressed with its tall snaking stems bearing cheery yellow flowers.  The information on this page is based on our research that has been conducted on this plant in our nursery library, from online sources, and from observations made of the crops growing in the nursery, plants in the nursery's garden and those in other gardens where we have observed it. We also have incorporated comments received from others and welcome getting feedback from those who may have additional information, particularly if this information includes cultural information that would aid others in growing Helianthus giganteus.