Aconitum napellus Monkshood Description Tall stalks of pale blue-violet flowers in June and July. Grows best in moist soils. If you long for delphinium but don't have enough sun, aconitum makes a good substitute. Poisonous. Sizes & Prices All Aconitum Characteristics Hardiness Zone: 4-8 Light requirements: Part Sun Height: 36" Native: No Sizes & Prices Size: 2 Yr $13.98 Other Information Aconitum cammarum 'Blue Lagoon' Monkshood Zone: 4-8 Part Shade HT: 10-12" Aconitum fischeri Monkshood Zone: 4-8 Part Sun HT: 36" Aconitum napellus Monkshood Zone: 4-8 Part Sun HT: 36" Aconitum x cammarum 'Bicolor' Monkshood Zone: 4-8 Sun/Part Sun HT: 3-4'