Delgenius™ Shelby Delphinium

Delphinium 'Delgenius Shelby'

Plants that Work®

Reblooming Deep Blue Spires Need No Staking, Blooming Summer Through Fall
Cold Hardy: Thrives in Zones 3-9
Grows 1-2 ft Tall and Wide
Showy Blue, Purple Blooms From Late Spring to Late Summer
Deer Resistant, Drought Tolerant, Rabbit Resistant

$38⁹⁰

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Find your Growing Zone

Plant Size

Product variants

Planting & Care

Where to Plant

Sunlight: Provide at least 6 hours of direct sunlight daily to ensure strong stems and the most vibrant purple blooms. While full sun is best, gardeners in hotter zones (7 and 8) may find that some afternoon shade helps the plant perform better during peak summer heat.
Soil: These plants crave rich, porous soil that drains well, as sitting in waterlogged soil is the quickest way to kill them. If you have heavy clay or sandy soil, amend it generously with compost to improve drainage and hold the right amount of moisture.

Watering Requirements

Keep the soil consistently moist during the first season to help the roots establish, checking it daily in hot weather. Even after establishment, Delphiniums are not drought-tolerant and require regular watering to support their lush foliage and large flower spikes. Inconsistent moisture can lead to plant stress, resulting in stunted blooms or issues with powdery mildew.

Pruning Tips

Deadhead the spent flower spikes immediately after the first flush of blooms fades to encourage a potential second wave of flowers later in the season. According to your growing zone data, you should perform a hard cleanup in late fall. Cut the entire plant back to the ground once the foliage has yellowed or died back after the first hard frost to keep the garden tidy for winter.

Fertilizer Needs

Because they expend so much energy producing large flowers, apply a balanced, slow-release fertilizer or a layer of compost in early spring as new growth emerges. Avoid high-nitrogen fertilizers, often used for lawns, as these promote weak, leafy growth rather than the strong flower spikes you want.

Delivery and Shipping

Preorder Shipping Schedule

We ship your plants when it's safe to transport them to your zone. Dates are estimated and subject to weather delays.

Zone 3-4	Week of March 30th
Zone 5	Week of March 16th
Zone 6-12	Week of March 2nd

Shipping Rates

Ships in 7-10 business days • Tracking provided • Weather protected

Under $50	$9.99
$50 - $99.99	$14.99
$100 - $149.99	$16.99
$150 - $198.99	$24.99
$199+	FREE

✓ Zone-specific timing • ✓ Professional packaging • ✓ Health guarantee

Understanding Our Container Sizes

At Nature Hills, our plants are sold in industry-standard nursery containers. You will notice we use the word "container" rather than "gallon." Container numbers follow a nursery trade size standard, not liquid volume. The number tells you the plant's size category and general maturity level. A larger container means a more established plant with a stronger root system.

Container Sizes

Quart

Plant age: 6 months to 1 year
Best for: Ground covers, perennials, ornamental grasses
What to expect: Our smallest and most affordable size. Well-suited for planting in multiples across a large area. Allow 1 to 2 seasons for full establishment.

#1 Container

Plant age: 1 to 2 years
Best for: Shrubs, perennials, smaller trees
What to expect: About the size of a large coffee can. A well-developed root system in a manageable size. Good value choice when you have time to let the plant grow into the space over a season or two.

#2 Container

Plant age: 2 to 3 years
Best for: Shrubs and trees where you want faster establishment
What to expect: A noticeable step up from a #1 in both plant size and root development. Good choice when you want visible presence without going to a larger size.

#3 Container

Plant age: 3 to 4 years
Best for: Most plants, most situations — flowering trees, shade trees, evergreen shrubs
What to expect: Our most popular size. Strong, developed root system. Plants in a #3 container make an immediate visual impact from day one. If you want a head start rather than waiting seasons for a plant to fill in, this is typically the right choice.

#5 Container and Larger

Plant age: 4 to 5+ years
Best for: Specimen plants, privacy screens, maximum instant impact
What to expect: Large, mature plants ready to make an immediate statement in your landscape. We also carry #7 and larger sizes for select varieties.

Why "Container" and Not "Gallon"?

Nursery container sizes follow an industry trade standard established for the nursery and horticulture industry. The number is a size designation, not a measurement of liquid volume. Actual soil volume varies by plant type, root mass, and growing medium. Using "container" is the accurate industry term. When you see #1, #2, or #3, think of it as the plant's size tier, not a gallon measurement.

Root Pouch Containers

Some Nature Hills plants arrive in a Root Pouch, a breathable fabric container made from 100% recycled materials. Root Pouches encourage denser root development through air pruning, which discourages root circling and promotes a stronger, more fibrous root ball at the time of planting.

Plants growing in Root Pouch fabric containers, showing the breathable woven fabric construction

There are two types. Knowing which one you have changes how you plant:

Degradable (brown or tan fabric): Plant the entire pouch directly in the ground. The fabric breaks down naturally in the soil over time.
Non-degradable (black or gray fabric): Remove the pouch before planting. Cut the bottom open with scissors, then peel the sides away. The fibrous root ball will hold its shape.

Not sure which type you have? Check the tag on your plant or contact us and we will confirm.

Full Root Pouch planting guide

Choosing the Right Size

Size	Plant Age	Best For
Quart	6 mo to 1 yr	Ground covers, perennials, grasses. Budget-friendly for mass plantings.
#1 Container	1 to 2 yrs	Shrubs, perennials, small trees. Value choice for patient gardeners.
#2 Container	2 to 3 yrs	Shrubs and trees where you want faster establishment.
#3 Container	3 to 4 yrs	Most plants. Immediate visual impact. Our most popular size.
#5 and larger	4+ yrs	Specimen plants, privacy screens, maximum instant impact.

Still not sure which size is right for your project? Our plant specialists are happy to help. Contact us and we will point you in the right direction.

Proven Winners® Delgenius™ Shelby Delphinium

Gorgeous packed spires, the Delgenius™ Shelby Delphinium PP#34657 (Delphinium 'Delgenius Shelby') is a spectacular reblooming perennial known for its brilliant deep blue blooms with full, densely packed flower spikes. Rising high on tall sturdy stems over a mound of lacy deeply incised green foliage, these are eye-catching blossoms!

A standout in the Delgenius™ series, Shelby combines superior branching, heat tolerance, and cold hardiness, making it an excellent choice for gardens across many climates. Unlike traditional Delphiniums, Shelby offers continuous blooms from early summer to fall with a compact, sturdy form that requires no staking.

Key Features of Delgenius™ Shelby Delphinium

Stunning deep blue blooms on tall, full flower spikes.
Extended bloom season, reblooming from early summer to fall.
Superior branching habit for maximum flower production.
Compact and sturdy, reaching 24-30 inches tall with no need for staking.
Cold hardy to USDA growing zones 3-9, are heat tolerant and widely adaptable.
Pollinator-friendly, attracting butterflies and bees.
Perfect for cut flowers with long-lasting blooms.
Deer and rabbit resistant for worry-free planting.

How to Use Delgenius™ Shelby Delphinium in the Landscape

Cottage Gardens & Perennial Borders

Plant Shelby in mixed borders to add vertical interest and bold color.
Combine with Roses, Coneflowers, or Coreopsis for colorful Cottage Gardens.
Use in mass plantings for a striking visual impact throughout the growing season.

Pollinator Gardens

Attract butterflies and bees with Shelby's nectar-rich blooms.
Include it in pollinator-friendly landscapes for season-long beauty and ecological benefits.

Container Gardening & Patio Displays

Shelby's compact habit makes it perfect for large containers.
Place on patios or decks to enjoy its vibrant blooms up close.

Cut Flower Gardens

Its tall, sturdy stems make it an ideal addition to fresh bouquets.
Cut back after the first bloom to encourage additional flowers for later in the season.

Delphinium Care & Maintenance

Delphinium are very easy to grow and hardy perennial plants!

Sun & Soil Requirements

Grows best in full sun to partial shade. Ensure at least 6 hours of direct sunlight for optimal blooms. Hot climates will find their plants do better with afternoon shade.
Prefers an enriched, well-drained soil with consistent moisture.

Watering & Mulching

Keep soil evenly moist, especially during hot, dry periods.
Add 3-4 inch layer of mulch around the base to help retain moisture and regulate temperature.

Fertilizing

Apply a balanced, slow-release fertilizer in early spring and again after the first bloom to promote continuous flowering.

Pruning & Deadheading

Deadhead spent blooms to encourage reblooming.
After the first flush of flowers, cut back the flower stalks to promote a second bloom cycle.

Winter Care: Shelby is cold hardy! Apply mulch or compost over the area in late fall to protect the root zone during harsh winters.

Order Delgenius™ Shelby Delphinium Today!

Bring vivid color and vertical beauty to your garden with Delgenius™ Shelby Delphinium. With its extended bloom season, compact habit, and reliable performance, Shelby is a must-have for any perennial garden.

Order now from Nature Hills Online Plant Nursery, and enjoy months of stunning blooms and low-maintenance beauty in your landscape!

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Growing Zones 3-9

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Frequently Asked Questions

What USDA hardiness zones is Delgenius™ Shelby Delphinium suitable for?

Delgenius™ Shelby Delphinium is cold hardy in USDA zones 3-9. This wide hardiness range, combined with superior heat tolerance, makes it adaptable to most climates across the continental United States. Plant in well-draining soil with full sun to partial shade for best results.

How tall and wide does Delgenius™ Shelby Delphinium grow at maturity?

Delgenius™ Shelby Delphinium reaches 24-30 inches tall with a compact, sturdy form that needs no staking. Its superior branching habit creates a full, well-rounded plant perfect for borders or containers. Shop this reblooming beauty at Nature Hills for continuous blooms all season long.

What are the planting zone requirements for Delgenius™ Shelby Delphinium in cold climates?

Delgenius™ Shelby Delphinium is cold hardy in USDA zones 3-9, thriving in even the coldest climates. This variety combines exceptional cold tolerance with heat resistance, making it widely adaptable. Plant in well-draining soil and provide full sun to partial shade for best performance.

Does Delgenius™ Shelby Delphinium need full sun or partial shade?

Delgenius™ Shelby Delphinium thrives in full sun to partial shade conditions. This heat-tolerant perennial performs best with at least 6 hours of morning sun daily, though it appreciates some afternoon shade in zones 7-9. Plant in well-draining soil for optimal blooms from early summer through fall.

How often should I water Delgenius™ Shelby Delphinium after planting?

Water newly planted Delgenius™ Shelby Delphinium deeply 2-3 times per week for the first month. Once established, this heat-tolerant perennial needs about 1 inch of water weekly. Check soil moisture regularly during hot spells to support continuous blooming through fall.

What are the care requirements for fertilizing Delgenius™ Shelby Delphinium?

Feed Delgenius™ Shelby Delphinium with balanced fertilizer in early spring when new growth emerges. Apply a second feeding after the first bloom cycle to support continuous flowering through fall. Avoid high-nitrogen fertilizers which can reduce blooming and weaken stems.