We proudly research, grow, and write about our plants by hand. Descriptions are based on our experience as well as information gathered from reputable sources: books, periodicals, and select websites. Should you have questions beyond what is listed please email or call.

Helianthus giganteus | giant sunflower

Regular price: $8.99
Regular price
Sale price: $8.99

Shipping calculated at checkout.

Grown from seed in living soil without the use of pesticides, chemicals, or carbon fuels.

All in stock plants will ship FALL 2026.

Giant sunflower (Helianthus giganteus) is a tall plant can be found growing naturally in swamps and moist lowlands throughout eastern and central North America. This perennial can top ten feet and is perhaps best saved for use in naturalized areas, especially where water is present. The creeping rootstock can form large colonies with time.

Zones: (4)5 to 9
Family: Asteraceae
Type: Herbaceous perennial
Height: 36 to 120 in.
Spread: 24 to 48 in.
Exposure: full sun
Soil: moist, wet
Bloom Time: July to October
Native Range: North America from New York and Ontario to Minnesota south to Georgia and Kentucky; naturalized northeastward

Syn. Helianthus alienus, Helianthus borealis

F6-b

4" pot

Special Characteristics

Pollinator favorite
Rabbit resistant
Architectural
Fast-growing
Deer-resistant
Rampant runner

image credits

Joshua Mayer (wackybadger), CC BY-SA 2.0, via Wikimedia CommonsThis image or recording is the work of a U.S. Fish and Wildlife Service employee, taken or made as part of that person's official duties. As a work of the U.S. federal government, the image is in the public domain. For more information, see the Fish and Wildlife Service copyright policy.Oceancetaceen - Alice Chodura, CC BY-SA 3.0, via Wikimedia Commons

Ordering information

Preorders

You may place your order anytime to reserve plants for fall 2026 shipping. If you place multiple orders, we will combine plants into one box (or as many as needed) and any extra shipping charges will be refunded.

We will resume shipping as soon as temperatures cool in our location and yours. This can range from the beginning of September for northern locations to the end of October for hot locations (Texas).

We will check in with you a week before shipping to make sure you receive your plants at a time that is convenient for you.

Shipping

Live plants ship in spring and fall only. Plants may ship dormant, depending on variety and season. Shipping costs are most reasonable when bundling like size plants.

4-inch: 1-6 plants ship for $15.00 / 7-13 plants ship for $18.00 / 14-30 plants ship for $40.00
1-gal: 1-2 plants ship for $18.00 / 3-4 plants ship for $25.00 / 5-6 plants ship for $40.00
trees & shrubs: $27.00-$40.00 each, height dependent
seeds: $6.75 or free with orders over $15.00

We regret that we cannot ship internationally or to the following states: AK, AZ, CA, CO, FL, HI, ID, MT, NV, OR, UT, or WA.

Nursery pick up

We will email you to schedule a day and time to collect your plants when they are ready in spring. Generally, plants can be collected from the nursery Monday through Sunday from 10am-4pm in Spring, Summer, and Fall.

Plant Sizes

We most commonly use the following pot sizes for perennials:

4-inch pot: 3.5" H x 3.5" W x 3.5" D
2-quart pot: 6" H x 5.25" W x 5.25" D
1-gallon pot: 6.87" H x 8" Dia (this is a true one gallon pot, not the smaller 'trade' one gallon pot used by many nurseries)

Check out our illustrated pot size guide here.

Representative trees & shrubs are photographed in their pots and posted on each plant page.

Sustainability

Sustainability is at the heart of what we do at The Old Dairy. We grow all of our plants outdoors without the use of chemicals, fertilizers, carbon fuels, or peat.

Many of our perennials are grown in the ground and dug upon order (this is especially true for larger sizes). This practice allows us to grow stronger, healthier plants using native soil, and ultimately reduces our impact on the environment.

Our open-pollinated seeds are collected from plants in our mother beds, which have never been treated with chemicals or sprays of any kind.

Read all about our sustainable practices here.