Monday, March 3, 2014

Keeping Spring Flowering Bulbs Happy by Rebecca Anderson

This morning I found some crocus (Crocus sp.) leaves peaking through the mulch.  It’s a sure sign spring is on its way when the crocus, daffodils (Narcissus sp.), hyacinths (Hyacinthus sp.) and tulips (Tulipa sp.) make their appearances.

Pampering these bulbs a little this year will help produce more abundant flowers next spring.  The roots are most active when the leaves are just starting to emerge, making this the best time to fertilize.  A soil test is always the best way to determine which fertilizer is ideal for your tulip patch, but in general Front Range soils have plenty of phosphorus and potassium (the P and K components of a fertilizer label).  This leaves nitrogen as the limiting factor (N, the first number in the fertilizer formula).  Blood meal is a good organic source of nitrogen that can be applied at a rate of 2 pounds per 100 square feet or 1 teaspoon per square foot if soil test results aren't available.  Gently loosen the soil around the bulbs if possible, sprinkle on the blood meal and water in.  A water soluble fertilizer can also be used.

Remove the flowers of your spring bulbs as soon as they've withered.  The bulbs won't rebloom, but this will keep the plant from using up energy making seeds.  Therefore more nutrients will be stored in the bulb for better flowers next year.  Don't cut leaves back right away though.  Wait for the leaves to die back before removing as they are gathering energy for the bulbs.  You can plant fast growing annuals around your spring bloomers to camouflage the bulb foliage for a fresher look in the flower bed in late spring or early summer. 

More information about caring for spring flower bulbs can be found in the CSU Fact Sheet Fall-Planted Bulbs and Corms