Cleistocactus strausii
The cactus prefers free draining soils, strong sunlight, but not high temperatures — in fact it can withstand hard frosts down to -10 °C. In its natural habitat it receives plenty of water during the summer, but almost none over the winter. In cultivation, watering too much in winter often leads to root rot.
Phytophthora megasperma
Water moulds in the "P. megasperma" complex can be found on a multitude of host plants, including many agricultural crops. It has been noted on soybeans, kiwifruit ("Actinidia deliciosa"), horse chestnut ("Aesculus hippocastanum"), hollyhock ("Alcea rosea"), asparagus ("Asparagus officinalis"), "Brassica oleracea", crops such as cabbage, cauliflower, safflower ("Carthamus tinctorius"), Port Orford cedar ("Chamaecyparis lawsoniana"), chickpea ("Cicer arietinum"), carrot ("Daucus carota"), carnation ("Dianthus caryophyllus"), eucalyptus ("Eucalyptus" spp.), walnut ("Juglans regia"), apple ("Malus domestica"), pines ("Pinus" spp.), stone fruit such as apricot, cherry, plum, and peach, Douglas fir ("Pseudotsuga menziesii"), sugarcane ("Saccharum officinarum"), and potato ("Solanum tuberosum").