Fall is the best time to plant spring-flowering bulbs to create a kaleidoscope of color next spring. Thousands of tulips and daffodils find their way into gardens each year. Bulbs are planted in the fall in order for them to develop a root system and to satisfy the cold requirement necessary for the robust, colorful flower buds.
It is best to wait until the ground has cooled to below 60 degrees before planting. For most of North Carolina that is October or November.
Good soil drainage is essential for spring-flowering bulbs. Poorly aerated soil is probably the biggest factor in bulbs that fail to naturalize and return year after year. If the soil is mostly clay, mix in an organic amendment such as compost or aged pine bark, 25 percent or more by volume. Or plant in raised beds that are well prepared. If the soil is sandy, add an organic amendment to increase water and nutrient holding capacity.
Soil pH is another critical issue for longevity of bulb plantings. The pH of the planting area should be in the 6-7 range. Frequently, both limestone and phosphorus fertilizer are deficient in new planting beds. One of the myths with bulb planting is that bonemeal gives better results. Studies at NC State University indicate that commercial bulb fertilizer is the preferred method of supplying nutrients. If you need assistance in this area contact your county Extension Center for a soil test kit.
Where to Plant
Use spring-flowering bulbs in borders with annuals or perennials, groundcovers, rock gardens and wooded areas. They do best in areas that receive light shade during midday, especially in hotter zone 8 gardens. Some bulb types, such as crocus, muscari and allium, can be inter planted in the same area based on time of flowering and plant heights.
In established bulb beds, summer is a good time to divide old plantings to ensure continuous flowering and bulb health. Before replanting, excavate new beds deeply, to as much as a one-foot depth. This improves aeration and drainage for the roots.
Space and Plant Bulbs According to Size
Plant bulbs to the proper depth. Measure from the base of the bulb to soil level:
— Small-sized bulbs (1 inch in height) plant 5 inches deep. Space small bulbs (crocus and snowdrop) 1 to 2 inches apart.
— Large-size bulbs (2 or more inches in height) plant 8 inches deep. Space large bulbs (tulips and daffodils) 3 to 6 inches apart.
These planting depths will help protect the bulbs against frost, animals and physical damage due to hoeing or other gardening chores. Be certain to thoroughly loosen the soil under the bulbs.
Plant dozens of bulbs in an area to create a more effective flower display. After covering the bulbs with soil, water thoroughly. Cover beds with 2-3 inches of mulch. Most bulbs are sensitive to hand weeding, mulch and grass weed killers. If the fall is dry, water as needed.
Fertilization improves bulb performance. In addition, fertilization encourages bulbs to naturalize. There are two fertilizer methods available for spring-flowering bulbs. The first system utilizes a single application at planting using a slow release bulb fertilizer. Incorporate the fertilizer into the rooting area. The second system uses 10-10-10 in the fall, followed by a repeat application of the same fertilizer as soon as you see new shoots breaking through the ground in late winter.
Gardeners complain most about the wildlife they encounter when attempting to grow bulbs.
Though squirrels will leave your poisonous daffodil bulbs alone, they may nibble a tulip flower. The real menace for lily growers is the presence of pine mice, also known as voles. Fortunately, there are legal ways to control voles, including snaptraps and rodenticides. For the average homeowner, a good cat or amending the soil with gravel or Voleblock goes a long way.
Not Just for Spring Anymore
Blub flowers are not just spring flowers, in the Carolinas, bulbs can bloom throughout the year, with a mix of species. Indulge yourself with the wonderful woodland varieties like magic lilies, autumn crocus and rain lilies. For vertical accents, scatter a few gladiola and crocosmia bulbs in a sunny perennial border. The Oriental lilies produce large, exquisite, picture-perfect blooms for cutting, while their smaller Asiatic cousins are made for color beds.
Fall is a great time to get out into the yard. For good gardening information, be sure to call Nancy Olsen, Bladen County Horticulture Extension agent, at 910-862-4591 or come by the office at 450 Smith Circle Dr., Elizabethtown.