Photo courtesy of StrawChicago Alkaline clay 5a
StrawChicago Alkaline clay 5a
Illinois, United States
Gypsum helps with root-growth. Sulfate of potash helps to induce blooms. All my 130 varieties are own-roots, except for 4 roses which are grafted-on-Dr.Huey. I don't spray. In my dolomitic heavy clay, pH 7.7, roses are healthy if I dig deep & wide for drainage, and fix my pH 9 tap water with sulfate of potash and gypsum.
My garden is NW of Chicago, zone 5a, more than 38" annual rain & 29" of snow. Summer heat up to 90-100 F. My soil is high in magnesium at pH 7.7. I fix my sticky & poor drainage and rock-hard clay with gypsum. Austin and French Meilland like my heavy clay. In contrast, 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.
For OWN-ROOT roses: PALE LEAVES prefer loamy soil & acidic rain. DARK-GREEN LEAVES like Intrigue prefer heavy/dense alkaline clay or alkaline-tap-water (pH 9 here).
GLOSSY LEAVES like Pat Austin and Twilight Zone: best with partial shade & wet & need alkaline minerals after heavy rain.
TINY LEAVES like William Morris prefer loamy & light and fluffy soil. LARGE LEAVES like Princesse Charlene de Monaco = vigorous & thick root that can handle clay
THICK LEAVES like Dee-lish and Double-Delight = heat tolerant.
5-leaflet = modern roses, OK with alkaline tap-water.
7-leaflet or thornless or blue-color = derived multiflora & need cooler sites & loamy & high-rain.
7-leaflet and many prickles = drought-tolerant & derived from Centifolia or Rugosa & prefer loamy/sandy & can handle hot & dry.
Over-fertilization: wilting, leaves curl down.
Too acidic: leaves curl up & thinner, and blackspots.
Too alkaline: Pale, 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
Iron def: pale UPPER leaves with greener veins
Experienced (34 years)
Last visit: Thursday, April 15th