Chilling Hours

Chilling hours are the hours of winter below 45° and above 32°. These hours are required for a plant to break dormancy (grow) in the spring. Global warming will affect us one winter so that the winter cooling is insufficient to the plant to break dormancy. As far as I know there is no manipulating this without breeding work. Can we GM our way out of this?

HERE IS MY LIST:

Yellow Bellflower, Winter Banana, Dorset Golden, Anna, Gravenstein, Newtown Pippin, Granny Smith, Pink Lady, Gala, Braeburn, Jonagold are a few. Trials: Aunt Rachel, Carter’s Blue

Reliable fruit trees in Santa Cruz County & Chill Hour (C.H.) Requirements:

Apples

Cox’s Orange Pippin Parentage

• Fiesta, Freyburg, Holstein, Queen Cox, Rubinette:

600–800 C.H.

• Corail (a.k.a. Sonata, Pinova): 800
• Cox’s Orange Pippin: 800

Golden Delicious Parentage

• Mollie’s Delicious: 400–500
• Gala: 500–600
• Mutsu: 600
• Golden Delicious: 700
• Jonagold (and related strains): 700–800
• Chehalis, Elstar: 800–1,000

McIntosh Parentage

• Beverly Hills: 300
• Shay: 700–800
• Empire Mac, Macoun, McIntosh, Rodger’s McIntosh, Spartan: 800

Russeted Apples (all of these crop reliably in Santa Cruz County)

• Gold Rush: 600
• St. Edmund’s Pippin: 600–700
• Hoople’s Antique Gold: 600–800
• Ashmead’s Kernal, Razor Russet Spitzenburg: 800
• American Golden Russet, Belle de Boskoop,

Hudson’s Golden Gem: 800–1,000

Other Apple Varieties

• Arkansas Charm: 400
• Pink Lady: 400–500
• Cameo, Fuji, Pink Pearl: 600
• Braeburn, Gravenstein, Yellow Newtown Pippin: 700
• Hauer Pippin, Sierra Beauty: 700–800
• Honeycrisp, Idared: 800
• Bramley’s: 800–1,000

Pears

Summer or Butter Pears

• Seckel: 500
• Bartlett: 500–600
• Warren: 600

Winter Pears

• Bosc: 500–600
• Comice: 600
• D’Anjou, Flemish Beauty, Orcas, Rescue: 800

Quinces

• Pineapple, Orange, Smyrna: 300–500

Pomegranates

• Sweet: 100
• Wonderful: 150

Persimmons

• Fuyu, Haychia: 100–200 (despite their low chill requirements,

they bloom late and set annually)

Peaches

Peach Leaf Curl Resistant Varieties

• Avalon, Mary Jane: 600
• Frost, Indian Free: 700
• Q 1-8: 700–800

Other Peach Varieties

• Babcock, Saturn (Peento, Donut): 200–300
• Late Elberta: 600–700
• Arctic Supreme: 700
• Baby Crawford, Indian Blood, Red Haven,

White Lady: 800

Nectarines

• Double Delight: 300
• Arctic Jay, Fantasia: 500
• Arctic Glo, Arctic Queen, Arctic Rose: 600–700
• Arctic Blaze (taste test winner): 700–800

Plums

• Beauty: 250
• Satsuma/Mariposa, Shiro (yellow): 300
• Catalina: 300–400
• Golden Nectar, Santa Rosa/Late Santa Rosa: 400
• Emerald Beauty: 600–700

Prune Plums

• Sugar Prune: 500
• Early Italian, French Improved, Italian Prune, Stanley:

800

Pluots

• Dapple Dandy, Flavor Grenade: 400–500
• Flavor Queen, Flavor Supreme: 500–600

Apriums

• Cot-N-Candy, Flavor Delight: 200–300

Apricots

• Blenheim (Royal): 400
• Moorpark: 600

Figs

• Black Mission, Blackjack (dwarf), Brown Turkey, Osborne

Prolific, White Genoa: 100 (despite their low

chill, they set reliably)

Cherries

• Stella (dwarf): 400
• Lapins: 500
• Craig’s Crimson (dwarf): 800

Walnuts

• Pedro (a somewhat “natural dwarf”): 400
• Chandler: 700