Alkaline clay StrawChicago zone 5a
Photo courtesy of StrawChicago Alkaline clay 5a
Member rose garden Listing last updated on 07 Dec 2023.
USDA Zone: 5a (-20 to -15 F / -28.8 to -26.2 C)
My garden is NW of Chicago, zone 5a, 38" annual rain & 29" of snow. Brutal summer heat up to 100 F. My soil is high in magnesium at pH 7.7. I fix my clay with gypsum & pine bark. Austin, French Meilland, and hybrid tea like my alkaline clay. Albas, damasks, hybrid perpetual, and esp. Rugosas & hybrid Musk prefer sandy and loamy soil & need good drainage. Multiflora prefers high-rain & acidic loamy soil, but wichurana (Dr. Huey) prefers drier & alkaline clay.
Gypsum helps with root-growth. Sulfate of potash helps to induce blooms. Most of my 110+ varieties are own-root, with a few grafted on Dr. Huey. I don't spray. In my dolomitic heavy clay, pH 7.7, roses are healthy if I dig deep enough for drainage (2.5 feet), and fix my alkaline tap water with sulfate of potash and gypsum.
My code for OWN-ROOT roses: PALE LEAVES prefer loamy soil & acidic rain. DARK-GREEN prefer heavy/alkaline clay GLOSSY: partial shade & wet & alkaline minerals. TINY LEAVES prefer loamy & drought-tolerant (species). LARGE LEAVES = vigorous & deep root. THICK LEAVES = heat tolerant.
5-leaflet = modern roses, OK with alkaline tap-water. 7-leaflet or thornless or blue-color = multiflora & cooler sites & loamy & high-rain. 7-leaflet and many prickles = drought-tolerant Centifolia or Rugosa & loamy/sandy & hot & dry.
Over-fertilization: wilting, leaves curl down.
Too acidic: leaves curl up & thinner, and blackspots.
Too alkaline: Pale leaves & top leaves twisted & crinkled (copper def).
Potassium def: zero blooms, balling, thin & weak stems, and blackspots.
Calcium def: less petals, stunt growth & tip die-back
Nitrogen def: small leaves & pale LOWEST leaves
Sulfur def: entire plant is pale & stunt growth
ON DISEASES & DIFFERENCES IN ROOTSTOCKS & pH preference:
SOIL CHEMISTRY AND BUFFERS TO NEUTRALIZE ACID RAIN:
MINERAL DEFICIENCY: http://forums.gardenweb.com/discussions/4034324/questions-on-mineral-nutrient-deficiency-in-pots-and-ground-and-fertilizer?n=65
TEST YOUR SOIL PH:
WHAT KILL ROSES IN WINTER: http://forums.gardenweb.com/discussions/4329440/keep-roses-alive-through-winter-and-differences-in-roots-rootstocks?n=15
ROSES THAT SURVIVE ZONE 5a: