For fiery greens that are a culinary delight, grow Japanese mustards. Leaves are ready for harvest when four inches long, usually four to six weeks after sowing. They can withstand some summer heat if planted in partial shade. Do go slow here as these are considered some of the spiciest of greens. Better known for its sunset hued flowers, both flowers and leaves are edible.
Nasturtiums grow like crazy in hot weather and the young leaves provide the best peppery bite.
Only their flowers are edible and they add wonderful color to salads. Milder mibuna and mizuna offer a starting point for those wanting to take a go-slow approach to savory salads. Quick to harvest, pick leaves on an as-needed basis and expect one plant to provide for many salads. For the lettuce base, butterhead, looseleaf and romaine types grow well in Colorado. Crisphead lettuce rarely sets a hard head according to many years of vegetable demonstration trial results at Colorado State University.