Squashes Resistant to Powdery Mildew

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Powdery mildew attacks various squash species in mid to late summer. Photo: gardenerd.comldew

Powdery mildew (PM), in which a white powdery growth appears on leaves in mid to late summer, causing distortion, dieback and a serious decline in productivity, is the most common disease of squashes and other cucurbits all over the world. There are actually many varieties of this disease, of which Podosphaera fuliginea (formerly Podosphaera xanthii) and Erysiphe cichoracearum are the two most common.

There are various ways of treating it (see Powdery Mildew on Squash and Cukes for some ideas), but one of the easiest is choosing squash varieties that are naturally resistant to PM. 

Resistant varieties are not necessarily immune to PM, but are less affected, often showing no or milder symptoms or the symptoms show up later, after the crop is harvested. Ideally, then, if powdery mildew has been a problem in the past, the wise gardener would choose resistant varieties in the following years.

A List of Disease-Resistant Squash

The varieties below are considered powdery mildew resistant. There are others, often identified by the letters PM or PMR after the cultivar name (i.e. ‘Butterscotch’ PMR) in better seed catalogs.

Look for resistant varieties in seed catalogs, both paper and online.

Summer Squash

Zucchini ‘Payroll’. Photo: sygentaflowers-us.com

Zucchini

‘Amatista’
‘Ambassador’
‘Astia’
‘Black Coral’
‘Cash Machine’
‘Citlali’
‘Cuarzo’
‘Dario’
‘Desert’
‘Dunja’
‘Elegance’
‘Emerald Delight’
‘Emerald Desire’ 
‘Endeavor’
‘Envy’
‘Equinox’
‘Esteem’
‘Everglade’
‘Felix’
‘General Patton’
‘Golden Glory’
‘Goldy’
‘Green Machine’
‘Hurakan’
‘Jacobo’
‘Judgment III’

Zucchini (cont.)

‘Justice II
‘Limon’
‘Linda’
‘Lynx’
‘Midnight Lightning’
‘Mutabile’
‘Obsidian’
‘Pascola’
‘Paycheck’
‘Payload’
‘Payroll’
‘Prestige’
‘Preference’
‘Respect’
‘Reward’
‘Sebring’
‘Sebring Premium’
‘Seduction’
‘Spineless Beauty’
‘Spineless’ King’
‘Spineless Perfection’
‘Spineless Supreme’
‘Yellowfin’
‘Wildcat’
‘Ziti’
‘#8517’

Crookneck

‘Delta’
‘Fancycrook’
‘Gentry’
‘Gold Star’
‘Prelude’
‘Prelude II’
‘Sunglo’

Straightneck

‘Blonde Beauty’
‘Cheetah’
‘Conqueror III’
‘Dalsey’
‘Multipik’
‘Organic Success’
‘Patriot II’
‘Success’
‘Sunray’

Winter Squash

‘Starry Night’ acorn squash. Photo: http://www.johnnyseeds.com

Butternut

‘Betternut’
‘Betternut 401’
‘Betternut 900’
‘BonBon’
‘Bugle’
‘Butterscotch’
‘Chieftan’
‘Hamilton’
‘Honeynut’
‘Indian Brave’
‘Jacqueline’
‘JWS 6823’
‘Metro’
‘RB 310’
‘Waldo’

Acorn Squash

‘Autumn Delight’
‘Celebration’
‘Harlequin’
‘Honey Bear’
‘Mardi Gras’
‘Royal Ace’
‘Starry Night’
‘Sugar Bush’
‘Sweet Lightning’
‘Sweet Reba’
‘Table Star’ ‘Table Treat’
‘Taybelle’
‘Tiptop’

Delicata

‘Bush Delicata’

Spaghetti Squash

‘Sugaretti’

Pumpkin

‘18 Karat Gold’
‘Aladdin’
‘Apollo’
‘Ares’
‘Bellatrix’
‘Big Doris’
‘Bisbee Gold’
‘Blanco
‘Blue Doll
‘Bumpkin’
‘Cannonball’
‘Captain Jack’
‘Carrie’
‘Casperita’
‘Charisma’
‘Conestoga Giant’
‘Cronus’
‘Darling’
‘Eagle City Gold’
‘Early Abundance’
‘Early Giant’
‘Early King’
‘Field Trip’
‘Gladiator’
‘Gold Dust’
‘Golden Condor’
‘Gooligan’
‘Grizzly Bear’
‘Hannibal’
‘Harvest Princess’
‘Hercules’
‘Hermes’
‘Hobbit’
‘Hooligan’
‘Indian Doll’
‘Iron Man’
‘Jason’
‘Jill-Be-Little’
‘Lil’ Ironsides’
‘King Midas’
‘Kratos’

Pumpkin (cont.)

‘Little Giant’
‘Magic Lantern’
‘Magic Wand’
‘Magician’
‘Mellow Yellow’
‘Merlin’
‘Midnight’
‘Miniwarts’
‘Mischief’
‘Mystic Plus’
‘Naked Bear’
‘Oktoberfest’
‘OneTooMany’
‘Orange Rave’
‘Orange Sunrise’
‘Orangita’
‘Porcelain Doll’
‘Porcelain Princess’
‘Prankster’
‘Pure Gold’
‘Pumpkin Rhea’
‘RockaFellow’
‘Scarecrow’
‘Secretariat’
‘Silver Moon’
‘Snowball’
‘Spark’
‘Spartan’
‘Specter’
‘Sunlight’
‘SuperHerc’
‘Sweet Lightning’
‘Touch of Autumn’
‘Warty Gnome’
‘Warty Goblin’
‘WeeeeOne’
‘Zeus’

Kabocha

‘Winter Sweet’