Great Blue Lobelia

As low as $39.59 was $59.99
Availability: In stock

Need a gorgeous blue flowering perennial that handles wet to very moist soil? The Great Blue Lobelia (Lobelia siphilitica) is a hardy Cardinal Flower bearing tall, leafy spikes of clear blue flowers. Members of the Bellflower Family, this showy perennial can be branched or unbranched, which you can encourage with pruning if you want more flowers, versus one large towering spire!

Great Blue is a clump-forming perennial with upright leafy stems. It blooms from late summer to mid-autumn and bears dense spikes of light to bright blue, but can sometimes be lavender or purplish because of their wide native genetic variability. Forming many tubular, two-lipped flowers with a more prominent lower lip. These are wonderfully long-lasting because they flower from the bottom to the top!

Great Blue will attract a plethora of curious butterflies to their nectar resources and the tubular flowers might even have a Hummingbird visitor or two! Perennial throughout USDA planting zones 4 to 9, this wetland native plant features mounds of lance-shaped green leaves with tall wands of dramatic flowering spikes rising high above them.

Planting and Application:

These spikes make it the perfect back-of-the-border plant in your perennial flower beds, Cottage gardens, and Rain Gardens! This perky perennial was made for your backyard pollinator gardens! Create groupings in water gardens or pond edges to draw the eye and give beneficial insects, like dragonflies, a place to land as they search for more pesky prey, like mosquitoes. This will make your outdoor enjoyment even better without these pests!

Of course, this Blue Cardinal Flower can also be used near the back of your property to soften the moist woodland edges or used at the base of a water feature you've installed. No matter where you plant Great Blue, it'll look absolutely stunning!

The tall flower spikes can be clipped and bright indoors to complete a delightful bouquet. Place them in the kitchen or on the living room coffee table to freshen up your space. By snipping a few blooms, you'll encourage more to rebloom throughout the growing season!

  • Tall Spikes of Blue to Purple Florets
  • Long-Lasting Blooms Until Mid-Autumn
  • Lush Green Lance-Shaped Foliage
  • Wetland Native Perennial
  • Great For Pollinators, Hummingbirds & Cut Flowers
  • Tall Specimens, Groupings, Back-of-the-Border, Water Gardens & Rain Gardens

#ProPlantTips for Care:

This full-sun perennial grows 2-3 feet tall, so 6 hours of direct sunlight is needed to maintain strong upright flowering stems. The Blue Cardinal Flower prefers deep, moist soil and should be fertilized every two weeks in spring and early summer to improve flowering.

Pinching back young plants encourages branching, or pinch back offshoots to encourage a single large flower per plant. These herbaceous Perennials may be trimmed as they die back in hot summers. Deadhead to encourage new blooms, and clean the mounds up in the early spring before the growing season begins.

  • Full Sun Perennials
  • Almost Any Soil That Isn't Stagnant
  • Moist to Wetland Conditions
  • Pinch Back, Deadhead In Summer & Prune In Spring
  • Deer & Rabbits Seldom Bother These

The beautiful blue cousin to the red Cardinal Flower is a refreshing native perennial to enliven your landscape with its unique color and form! Order the Great Blue Lobelia today at Nature Hills, and go native!

Buying Options for Plants

Nature Hills sells a large variety of plants with several options available. Plants are offered in both potted containers and as dormant bare root without soil. Here is a helpful resource to understand your options as you create a beautiful landscape with help from Nature Hills.

Ever wonder what a larger plant will mean for your landscape? Container Sizes are really all about the age of the plant!

Seasonally, Nature Hills offers hand selected, high quality bare root trees, shrubs and perennials. Bare root plants are sold by height from the top of the root system to the top of the plant. Plants may be taller than the height minimums.

  • Popular sizes of select trees are 1 foot, 2 feet, 3 feet, etc.
  • Popular sizes of select bare root plants is 1 foot, 18 inches, etc.

Nature Hills Container Size by Volume

Keep in mind, specific varieties and different growing conditions can affect the rate at which plants grow. Variations in size may occur.

Young Plants to 18 Months
Size Volume
2"x2"x3" Ranges from .18 to .21 dry quarts / .198 to .23 dry liters in volume
4.5" Container Equal to .65 dry quart / .72 dry liter in volume
Sprinter Pot Equal to .63 dry quart / .69 dry liter in volume
4" Container Ranges from .31 to .87 / .35 to .96 dry liter in volume
6" Container Equal to 1.4 dry quarts / 1.59 dry liters in volume
1 Quart Equal to 1 dry quart / 1.1 dry liter in volume
5.5" Container Equal to 1.89 of a dry quart / 2.08 dry liters in volume
4"x4"x5" Ranges from .8 to 1.1 dry quarts / .88 to 1.2 dry liters in volume
4"x4"x6" Ranges from 1.0 to 1.3 dry quarts / 1.1 to 1.41 dry liters in volume
4"x4"x9" Ranges from 1.1 to 2.1 dry quarts / 1.2 to 2.3 dry liters in volume
4"x4"x10" Ranges from 1.7 to 2.3 dry quart / 1.87 to 2.53 dry liters in volume
Plants 18 Months - 2.5 Years Old
Size Volume
2 Quart Equal to 2 dry quarts / 2.2 dry liters in volume
#1 Container Ranges from 2.26 to 3.73 dry quarts / 2.49 to 4.11 dry liters in volume
5"x5"x12" Equal to 3.5 to 4.3 dry quarts / 3.85 to 4.74 dry liters in volume
Plants 2 - 4 Years Old
Size Volume
#2 Container Ranges from 1.19 to 1.76 dry gallons / 5.24 to 7.75 dry liters in volume
#3 Container Ranges from 2.32 to 2.76 dry gallons / 10.22 to 12.16 dry liters in volume
Plants 3 - 5 Years Old
Size Volume
#5 Container Ranges from 2.92 to 4.62 dry gallons / 12.86 to 20.35 dry liters in volume
#6 Container Ranges from 5.25 to 6.01 dry gallons / 23.12 to 26.42 dry liters in volume
#7 Container Ranges from 5.98 to 6.08 dry gallons / 26.34 to 26.78 dry liters in volume

About Plant Sentry™

Plant Sentry is designed to protect both consumers and the nursery trade from invasive plant pests and diseases. Sites that display the Plant Sentry protection badge are protected from consumers buying and nurseries shipping material carrying invasive pests and diseases.

This proprietary eCommerce software prevents the shipment of a restricted plant to each state. The Plant Sentry system includes a shipment certification program. The Plant Sentry Compliance Officer works closely with and each nursery or fulfillment center to ensure only compliant plants are sold to customers.

Click Here to learn more

Plant Sentry


To obtain a more accurate shipment time-frame, simply enter your zip code in the “Find Your Growing Zone” box to the right. Our plants are grown all over the country and lead time on items may be different because of this. Once your order is placed, you will also receive the specific shipment time-frame information as part of your order confirmation. Once an item ships, you will receive shipment notification and tracking numbers, so you can follow along while your plant travels to your doorstep. We use FedEx, UPS, or USPS at our discretion.

Due to winter weather we have put a hold on shipping to the areas shown below in grey. You can still order now and we will ship the plant to you during an appropriate time for your zone.

*If you have found your zone already, it will be highlighted in the table below.
Color Zone Times
3 Spring 2019
4 Now
5 Now
6 Now
7 Now
8 Now
9 Now
10 Now
11 Now

Shipping Rates

At Nature Hills we handle, package and ship the products you order with the utmost care to ensure healthy delivery. Shipping and handling charges are calculated based on the tables below. Please note that some items include an additional handling surcharge, these will be noted on the item's product page.

From To S&H
0 - 19.99 24.99
20 - 49.99 29.99
50 - 69.99 34.99
70 - 99.99 39.99
100 - 129.99 44.99
130 - 149.99 48.99
150 - 150+ Approx 28%

Click here to see our full rates


Great Blue Lobelia Is Suited to Grow in Zones 4-9
Growing Zones 4-9
More Information
Brand Nature Hills' Choice
Botanical Name Lobelia siphilitica
Type Perennial
Mature Height 2 - 3 feet
Mature Spread 18 - 24 inches
Sun Exposure Full Sun
Soil Adaptable
Moisture Moderate to High - Tolerates Wet Soil
Growth Rate Medium
Flower Color Blue to Purple
Foliage Color Green
Pollinator Friendly Yes
Pruning Time Early Spring
Fragrant No