Annual vines add quick coverage to trellises. Use them to create a living privacy screen or to add color to vertical surfaces. Red cardinal vines have fern-like foliage and small, brilliant red flowers. They thrive in full sunlight, where ivy and other perennial vines quickly become scorched. They are also mildly drought-resistant, therefore can survive short periods of dry weather in summer when other plants begin to wilt. Planting and growing red cardinal vines is not difficult, though the seeds require some preparation prior to planting.
Scuff one side of the seed with a metal file or piece of sandpaper, scuffing off just the outer seed coat until the lighter inner coating shows through. Place the nicked seeds in a bowl of warm water and leave to soak overnight. This breaks the seeds dormancy, speeding germination.
Prepare a full-sun, well-drained garden bed near a trellis or fence. Lay a 2-inch layer of compost over the planting area and till it in to the top 6 inches of soil to provide nutrients and aid drainage.
Sow the prepared seeds ½ inch deep and space them 2 to 4 inches apart. Space them within 6 to 8 inches of the base of the fence or trellis.
Water immediately after planting. Water daily as necessary to keep the soil moist but not soggy until the plants are approximately 6 inches high. Once the cardinal vine reaches 6 inches, water when the surface of the soil begins to feel dry.
Guide the young vines onto the trellis. Wind the tips once or twice clockwise around the trellis if they do not begin climbing on their own.
Pinch the tip of each vine when it reaches the top of the trellis. This encourages branching, stops vertical growth and leads to a fuller vine.