Q. Should I use bone meal when planting my spring flowering bulbs?
A. Bone meal was traditionally used at planting as a source of nutrients for newly-planted bulbs. Not only did it contain lots phosphorous and calcium for promoting good growth, it contained other nutrients from the scraps of meat and bits of marrow that were attached to the bones.
Now the bones are steamed and cleaned before grinding so the nutrient value is slightly less. As a slow release fertilizer, bone meal is primarily used as a source of phosphorous (28 percent by weight). It is often used in planting holes for bulbs to help promote fall root growth.
The idea is to mix the bone meal into the soil below where the bulbs will be planted so it can be used by the newly-emerging roots.
It is very possible that you won't need any phosphorous at planting because the majority of New Hampshire garden soils already have plenty of phosphorous. Since phosphorous doesn’t move or leach through the soil profile, it is rarely deficient if fertilizer has been applied to a garden in the past. A soil test can tell you if you need to add phosphorous.
May Attract Unwanted Guests
In addition, the nature of bone meal tends to attract skunks, raccoons and dogs that will dig up your bulbs looking for bones. A better choice might be to use a slow release fertilizer applied according to label directions. Because most spring flowering bulbs have all the energy stored up for next season’s bloom, the benefits come in the second season when fertilizer applied at planting helps your bulbs maintain vigorous growth and large flowers.
Originally published September 19, 2013