The illustrated growing guide

Petunia

Petunia × atkinsiana

Family Solanaceae

Est. zones 2-11

Botanical illustration of Petunia — Annual · Petunia × atkinsiana

The hanging-basket engine of American porches. The late-July haircut plus a feed reboots tired baskets into a September encore.

Annual

☤ Juglone-sensitivePetunia is sensitive to juglone — the toxin exuded by black walnut, butternut, and their relatives. Keep it 50+ ft from any walnut or hickory, or its leaves will yellow, wilt, and die back for no obvious reason.

Where to buy the plant — 3 nurseries

Overview

Will petunia suit your garden, and what goes wrong.

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Will it thrive where you are?

Enter your ZIP — we look up your USDA hardiness zone (2023 map) and check it against what petunia actually needs.

Life cycleTender perennial, grown as an annual

Petunia at a glance

Life cycleTender perennial, grown as an annual

Mature size6-18 in, trailing types to 3 ft

PollinationHummingbird moths at dusk

Chill requirementNot yet established

Bloom seasonMay - Frost nonstop

Harvest seasonNot yet established

Growth rateFast

Common petunia problems

Aphids
Budworms (holes in buds = caterpillar)
Botrytis in wet spells

Growing

Light, water, soil, propagation and the season’s jobs.

How to grow petunia: light, water & soil

LightFull Sun

WaterModerate — containers daily in July heat

SoilWell-drained, average · pH 5.5 - 6.5

FertilizerEvery 2 weeks in containers — they're hungry bloomers

PruningNone — Old types need deadheading; modern Wave/Supertunia types self-clean — just shear by a third in late July when leggy.

Spacing10-12 in

When to spray petunia

Growing season. Bt for budworms if buds vanish.

Timing only — the label is the law

This is when to watch and when a treatment is worth considering, not a recommendation to apply any product. Read and follow the product label before you spray — under federal law the label is the legal instruction, and using a pesticide against it is illegal.

Check the pre-harvest interval. Every product that’s cleared for an edible crop sets a minimum number of days between spraying and picking. Find it on the label before you spray anything you intend to eat.
Check the re-entry interval before you or anyone else works in the treated area again, and use the protective equipment the label names.
Confirm the product is registered for petunia in your state. A product legal on one crop is not legal on all of them, and state registrations differ — your state pesticide agency or local extension office can confirm both.
Rates and mixing instructions come from the label, never from us. We don’t publish them because they differ by product and formulation.

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The year

What petunia asks for, month by month.

The petunia year, month by month

MonthJanFebMarAprMayJunJulAugSepOctNovDec

Bloom

What each band means

Bloom — flowers open — pollinators working, frost on blossoms is the danger.

The petunia year as text

Jan quiet month
Feb quiet month
Mar quiet month
Apr quiet month
May bloom
Jun quiet month
Jul quiet month
Aug quiet month
Sep quiet month
Oct quiet month
Nov quiet month
Dec quiet month

These are the species' typical months — expect them a few weeks earlier in warm zones and later in cold ones. Watch the plant, not just the calendar.

Ecology & uses

What it does for the garden, and what it is grown for.

Petunia in the garden system

AttractsHummingbirds

MoistureFacultative / average

DeerBrowsed — protect young plants

OriginIntroduced

What petunia is grown for

✓ Not known to be toxic

UseBaskets

UseWindow boxes

UseMassing

Edibility, identification, and traditional-use notes here are general reference — not medical or veterinary advice, and not a claim that any plant treats or prevents anything. Medicinal ratings record how strongly a plant features in herbal tradition, nothing more. Never eat or dose a plant you have not positively identified. More on how to use this library.

Cultivars

Named varieties of petunia, ruled as a catalogue.

Best petunia varieties & cultivars

'Wave' series (spreading); 'Supertunia Vista' (monster baskets); 'Night Sky' (speckled)

Sources & plant ID

Where the care distinctions come from, and how the plant is filed.

Research basis

Sources behind this profile

No extension citations are attached to petuniayet. The care figures below come from the library's own catalogue rather than a traced primary source.

Plant ID

BinomialPetunia × atkinsiana

FamilySolanaceae

TypeAnnual · Tender Perennial

USDA symbolPEAT7

OriginIntroduced

Invasive riskLow

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Where to buy

Third-party nurseries — not Story Thyme Farms.

Third-party nurseries, not Story Thyme Farms. Prices are theirs.

Story Thyme Farms may earn a small commission from these links, at no cost to you — it never changes what we recommend.

Fast Growing TreesMexican Petunia$94.95↗Botanical InterestsPetite Charmer Blend Petunia Seeds$2.69↗Botanical InterestsGarden Party Blend Petunia Seeds$3.49↗

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Questions

Petunia questions, answered straight.

Is petunia safe for kids and pets?

Petunia is commonly eaten and isn't considered toxic, but "commonly eaten" isn't a guarantee for any particular person or animal — allergies, quantity, and which part you eat all matter. Never eat a plant you haven't positively identified, and check with a vet before letting pets or livestock graze anything new.

Elsewhere

Where petunia sits in the library.

Grows in the same world