Fall Perennial Bulb Planting for Spring Color

The Fall season is generally considered the end of the gardening year. The last task is to prepare for the next year and ensure that Spring will arrive with a flowering of perennial bulb color. Choosing the proper bulbs for each location, type of bed (formal vs naturalized) and the bulbs to plant is made simple following this easy guide. By preparing the beds, fertilizing and planting perennial fall bulbs at the end of the garden season the next Spring will be one full of lasting color and beauty.

Bed Preparation for Bulb Planting

For perennial bulbs to flourish and return year after year it is imperative that they be planted in fertile, well drained beds. Hard soil (i.e. clay soils) will hinder spreading and are generally not sufficiently nutrient rich to encourage good flowering. Peat moss, sphagnum, compost, straw or other organic matter will loosen soil and improve drainage. Some locations may require ‘raising’ the bed by transporting additional soil to the location.

The bed should be cultivated to a depth of 6″ to 8″, a small motorized tiller is excellent for this procedure (comparison of models here). Despite the addition of organic nutrient rich material it may be necessary to provide additional nutrients. Before planting bulbs, and in especially infertile or nutrient deficient areas it is advisable to mix a fertilizer containing phosphorus such as rock phosphate, superphosphate, or special bulb fertilizer into the soil.

Shade and Partial Sun: Naturalized and Formal Garden

Many lawns contain large shade trees and shrubs. Early blooming bulbs will do well under these types of deciduous plants as the foliage comes later that the flowers bloom, allowing them to get enough sunlight to provide sufficient fuel for the next springs bloom. Many bulbs which are early bloomers such as grape hyacinths, crocus, winter aconites, snowdrops, siberian squill, leucojums, bluebells and early maturing daffodils are suited to shaded areas and woodland or naturalized types of bulb gardens.

Border beds are usually associated with tulips, daffodils and amaryllis which require more sun. Use growing guides to determine mature flower height and plant accordingly with taller plants to the rear. Border gardens are often planted in rows, and a small hand plow is recommended for larger beds. The formal garden look lends it’s self to border beds and long lines of colors are their hallmark.

A general rule of thumb is to plant bulbs (pointed ends up) 3 times as deep as the bulbs greatest dimension. Larger and sun planted bulbs such as tulips and daffodils should be planted 4 to 6 inches apart with squill, crocus and snowdrops one to two inches. It is recommended to intersperse early, middle and late spring blooming bulbs to maintain bed color over a longer period of time.

Before planting fall perennial bulbs survey the area and ascertain which bulbs are appropriate to the specific site. Prepare the beds by cultivating the soil to 6 to 8 inches and incorporating organic material to improve drainage and increasing fertility. Plant bulbs according to light requirements, bunching for woodland/ naturalized gardens or in rows for formal beds. Planting fall perennial bulbs will ensure color in the Spring.

Sources:

“Bulbs” The Old Farmers Almanac

“Landscaping With Bulbs” University of Illinois Extension

“Fall Planting for Spring Flowers” The Green Mountain Gardener: University of Vermont Extension

“Growing Perennial Flowers” Purdue University Cooperative Extension Service