Both freesia and ranunculus perform best when cultivated in locations with full sun exposure and organically-enriched, well-draining soil. Select a planting site that receives six or more hours of direct sunlight each day to ensure prolific blooming. Amend the soil in your garden bed with 3 inches peat moss, 2 inches leaf mold and 1 inch perlite or vermiculite; use a tiller to incorporate the organic materials into the soil to a depth of 6 inches. For best results, select and prepare your planting site in the early spring.
Plant freesia corms and ranunculus tubers in your garden in the early spring to ensure that they both bloom in the summer. Wait to plant your corms and tubers until temperatures are consistently between 55 and 70 degrees Fahrenheit; ideal planting time is usually mid to late March in areas where freesia and ranunculus are hardy. Soak the freesia corms and rununculus tubers in a bowl of warm, but not hot, water for one hour before planting; this encourages them to sprout more quickly. Plant the prepared freesia corms at a depth of 5 inches; space multiple corms 4 to 6 inches apart. Ranunculus should be planted under 2 inches of soil; allow 4 inches between small tubers and up to 1 foot between large tubers.
Water the freesia and ranunculus thoroughly after planting; provide as much water as needed to moisten the soil to a depth of 6 inches. Water freesia and ranunculus weekly during the spring and summer months to ensure that they have the moisture necessary to bloom profusely; provide up to 1 inch of water each time you irrigate. Never allow the soil to become flooded or waterlogged; prolonged exposure to overly wet soil causes the corms and tubers to become mush and rot.
Freesia and ranunculus require regular fertilization to produce their characteristic summer blossoms. Fertilize your freesia and ranunculus with an application of a balanced, water-soluble fertilizer two weeks after planting the corms and tubers. Apply an application of a water-soluble, high-phosphorus fertilizer in late spring or early summer, when the plants start to set their flower buds. Over-fertilization can burn the roots of your plants, making it hard for them to absorb the moisture and nutrients they need for healthy development and blooming; always follow the application and rate instructions on the product label.