Planting Crocosmia Seeds. On heavy soil, you’ll need to add plenty of grit to the planting holes. Crocosmia bulbs require very little care after planting.
Place them with the pointy end facing up. Water them weekly and early in the morning when the top of the soil feels dry. a little maintenance goes a long way when cultivating crocosmia. Crocosmia plants grow two feet tall in a season.