Heat tolerant dahlias: beat the heat with these 120 choice varieties

best heat tolerant dahlias: AC Ben
Image by kind permission of the National Dahlia Society

It is essential to select from the best heat tolerant dahlias if you are growing dahlias somewhere like Florida or other Southern States of the USA, or if you are even trying to grow dahlias in a tropical climate.

The same applies if you are growing dahlias in parts of Australia. I lived there for ten years and we had substantial periods of intense heat, with temperatures over 40°C (104°F), that were a real threat to my dahlias and other garden plants.

What is more, the effects of climate change mean we see increasingly frequent prolonged heatwaves in Europe and elsewhere. Therefore, finding the best dahlias for heat might be something we dahlia growers need to do, wherever we are in the world.

Of course, dahlias need warmth and they need to be placed in a sunny spot. But dahlias originate from mountainous regions with sun, but cooler nights. It follows, then, that they are better adapted to those kinds of conditions.

This means that if you have conditions that will expose dahlias to very high temperatures over long periods, and/or searing hot sun, you will find that not all dahlia cultivars will do well.

This article is therefore aimed at helping you find the best heat tolerant dahlias. You’ll find recommendations from hot climate dahlia growers, and you will find more than a hundred cultivars listed in the table below.

These recommendations are therefore going to help you if you are growing in the USA and especially if you are looking for the best dahlias for zone 9, (zones 9a and 9b), zone 10, and zone 11.

Obviously, these dahlias will do well in other zones too – it is just that they are better adapted than others to the warmest conditions.

best heat tolerant dahlias: Peaches'n'Cream
Dahlia Peaches ‘n’ Cream Image by kind permission of the National Dahlia Society

The growers from the Dahlia Society of Georgia are used to growing in hot conditions and they have published some useful lists of heat tolerant dahlias, sorted by flower size and alphabetically.

In addition, Paula of Garden Bee Flower Farm in North Carolina grows dahlia in hot conditions for tubers and for cut flowers. She recommends the following varieties:

  • Peaches N Cream
  • Rose Toscano
  • Blyton Softer Gleam
  • Snoho Doris
  • Robin Hood
  • Valley Rust Bucket
  • Jessie G
  • Dark Spirit
  • Parkland Tribute
  • Ferncliff Spice
  • Blizzard
  • Black Satin
  • Camano Zoe
  • Maarn
  • Mystique
  • Sylvia Craig Hunter
  • Orange Globe
  • Woodland Wild Thing
  • Islander
  • Wyn’s Moonlight Sonata
  • American Beauty
  • Gitts Crazy, and
  • Hollyhill Black Beauty.
Heat tolerant dahlias: Gladiator
Dahlia Gladiator. Image by kind permission of the National Dahlia Society

Selection of the best heat tolerant dahlias

I’ve gone through the various sources and, for convenience, I’ve set out below a selection of more than 100 of the best heat tolerant dahlias you will find.

Dahlia Cultivar NameDahlia Type/VarietyColours
AC AbbyCactusYellow and Red
AC BenSemi-CactusOrange and Yellow
Amy KSemi-CactusPink and White
Audrey GraceFormal DecorativeRed
Bishop of LlandaffPeonyDark Red
Blue BayouAnemoneLavender
BodaciousInformal DecorativeRed
Brian RFormal DecorativeLavender
Bristol FleckDecorativePurple and White
Camano BuzFormal DecorativeOrgange
Clearview ClaretSemi-CactusRed
Croydon MasterpieceInformal DecorativeBronze
Downham RoyalMini BallPurple
Dueil Du Roi AlbertDecorativeDark Red
Elsie Huston Informal DecorativeDark Pink
ElviraPeonyDark Pink
Felida Stars & StripesStellar/StarDark Orange and Red
Ferncliff CopperFormal DecorativeBronze
Ferncliff IllusionInformal DecorativeWhite and Yellow
Gaylen RoseFormal DecorativeWhite
Ginger’s BabyFormal DecorativePurple and White
Gitts AttentionInformal DecorativeWhite
GladiatorInformal DecorativeRed
Glen Valley CathySemi-CactusYellow and Red
GloriosaFormal DecorativeYellow and Red variegated
Gonzo GrapeFormal DecorativePurple
GreendorBallYellow and Red variegated
Hamari AccordSemi-CactusYellow
Hamilton LillianFormal DecorativeOrange
Hann HitosujiCactusPink and Yellow
Harry MegosInformal DecorativeYellow and Orange
Hart’s Blood RedFormal DecorativeRed
Hart’s Dr McMurryInformal DecorativeOrange
Hollyhill QuintessenceSemi-CactusPink and White
Hollyhill Spider WomanNovelty Double CenterPurple and White
Hy MomCactusWhite
IslanderInformal DecorativePink
Ivory PalacesInformal DecorativeYellow
Janal AmySemi-CactusYellow
Japanese BishopPeonyRed
Jessie GBallPurple
JomandaFormal DecorativeOrange
JuanitaCactusDark Red
Kari Fruit SaladCactusPink and Yellow
Kelvin FloodlightFormal DecorativeYellow
Kenora FrillsLacianatedDark Pink
Kenora MajesticCactusYellow and Red
Kenora SunsetSemi-CactusYellow and Red
Kenora WildfireSemi-CactusRed
Lismore MoonlightPeonyYellow
Little LauraMini BallYellow and Orange
Little SnowdropPeonyWhite
Lupin SheilaOrchidPink and White
Manor JubileeInformal DecorativeDark Red
Marie SchnuggOrchidRed
Midnight StarOrchidDark Red
Minerva magicLacianatedWhite
Mingus AlexInformal DecorativeDark Red
Mingus PhillipSemi-CactusLavender and White
Mom & DadSemi-CactusPink and Yellow
Ms JulieStellar/StarRed and White
Ms PrissyStellar/StarDark Red
My WifeLacianatedRed
Narrows TricaSemi-CactusYellow
Nicole CCactusOrange
North-West CosmosSingleLavender and Purple
Olson’s FollyFormal DecorativeOrange and White
Oreti BlissSemi-CactusWhite
Oreti StacyLacianatedPink and White
Park PrincessCactusPink
Penhill WatermelonInformal DecorativeBronze
Pink PetStellar/StarPink
PoohCollaretteYellow and Red
Prince NoirInformal DecorativeDark Pink
Purple JoyFormal DecorativePurple
Red VelvetWaterlillyRed
Ruthie GWaterlillyPink and Yellow
Ryecroft JanFormal DecorativeWhite
Sam HustomInformal DecorativeOrange
Sandria JoyWaterlillyYellow
Sir RichardMini BallDark Pink
Smooth OperatorCactusRed
Snoho PeggtBallDark Pink
Spring FlagSemi-CactusPink and Yellow
Sterling SilverFormal DecorativeWhite
Taratahi RubyWaterlillyLavender and White
TartanInformal DecorativeDark Red and White
Thomas A. EdisonFormal DecorativePurple
Tui AvisCactusPink
TylerFormal DecorativePurple and White
UrchinLacianatedDark Pink
Veronne’s Taylor SwiftStellar/StarYellow and Red
Verrone’s DFStellar/StarPink
Verrone’s Pink GiraffeOrchidLavender and Pink
Walter HardistryInformal DecorativeWhite
WheelsCollaretteYellow and Red
White NettieMini BallWhite
Wine and RosesWaterlillyPurple and White
Wine FrostWaterlillyRed and White
Heat Tolerant Dahlias

Dahlia Veronne's Pink Giraffe
Dahlia Veronne’s Pink Giraffe. Image by kind permission of the National Dahlia Society

Growing Heat Tolerant Dahlias

Adjust your timings

Dahlias more or less stop growing when temperatures get really high, so the plants self-regulate to some extent, going partially dormant until temperatures cool down.

So, where temperatures are continually hot throughout the summer, you will probably find that you’ll have more success with dahlias, including heat tolerant ones, if you plant them out in September to bloom through the cooler months of autumn.

Soil and Location

When growing dahlias in hot climates, managing soil and location is crucial. Dahlias prefer a well-drained soil, rich in organic matter. It is essential to choose a location with morning sun and some light afternoon shade to prevent the plants from overheating.

Consider investing in some shade netting or shade cloth if you have no natural shade. In my experience this can make a big difference.

Dahlia Urchin
Dahlia Urchin Image by kind permission of the National Dahlia Society

Watering Practices

Dahlias grown in hotter climates need to be well hydrated to thrive. Deep and regular watering is crucial for their root system. It’s best to water the plants early in the morning or late in the evening to minimise evaporation.

You also need to pay close attention to the ongoing moisture levels in the soil as dahlias are sensitive to dry conditions. They do a lot of growing in a short space of time and they need plenty of water to make that happen.

However, don’t allow the soil to be saturated for long periods. Good drainage is essential, otherwise the roots and tubers may rot.

Mulching and Heat Protection

It is important to apply a good layer of mulch around dahlias in hot climates – I apply mulch 4 to 5 inches deep in extreme conditions. This can help regulate the soil temperature, keeping the sensitive feeder roots cool. Mulch options include home made compost, wood chips, bark, herbicide-free straw, hay, or leaves. Mulching also helps to retain soil moisture and keep weeds at bay.

In addition, it is a really good idea to mist your dahlia plants when the heat is intense, especially in the afternoon heat. You can rig up an automated misting system or just get out there and turn your hose to the fine spray setting. Obviously, an automated system is likely to be be more regular and reliable, and therefore the better option if high heat is constant throughout the summer where you are.

Pruning and Deadheading

Proper pruning and deadheading are essential for promoting flowering. To encourage bushier growth and increased flowering, pinch or cut back the main stems when the plant reaches about 12 to 18 inches in height. Regularly remove spent blooms, also known as deadheading, to stimulate more flowers and extend the flowering season.

It is also worthwhile keeping an eye on the plant’s health and remove any yellow or damaged leaves. This not only improves the plant’s appearance but also helps prevent the spread of diseases and promotes better air circulation.

Protecting from Pests

Dahlias can attract various pests like aphids, spider mites, and thrips. It is crucial to inspect plants regularly for any signs of pest infestation. Remove pests by hand or use a mild insecticidal soap or neem oil to help control them. Additionally, consider planting dahlias alongside other flowers like marigolds, which are known to repel pests naturally.

More on Growing Dahlias

You can also get much more guidance on growing dahlias in these posts:

Love Dahlias?I've written the book on them

Check out my comprehensive step by step guide, with plain language explanations and ultra-useful images and illustrations. This is for you if you love dahlias and want to the best out of the dahlias you grow.

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