Spring Care for Bulbs

Spring flowering bulbs such as tulips, crocus, hyacinths and daffodils require little care during the early spring when flowering. Established bulbs should be fertilized lightly each spring just as the foliage begins to come through the soil. Both during and after flowering, bulbs profit from plenty of moisture, but should remain fairly dry during dormant summer months. Bulbs need about 1 inch of rain while they are actively growing, so if you experience a spring drought, they should be watered heavily once a week which will greatly enhance the next year’s blooms.

Daffodils do not require deadheading

After spring-flowering bulbs have faded, snip off the dead flowers so they won’t go to seed. Daffodils are the only exception as they do not require deadheading. It is important to let the green foliage die back naturally, a process that generally takes about six weeks. The longer the foliage lasts, the better the blooms will be the following year. Many gardeners have the urge to tidy up bulb plantings after bloom by tying up the leaves with string or rubber bands. The six-week leaf die-back time is a critical time period for leaves busy with photosynthesis, and the leaves must be free to soak up sunshine during this crucial period. I have inter-planted my perennials with my bulbs to hide the dying foliage of the bulbs. Some perennials that work particularly well for this purpose are daylilies, hosta, bleeding heart, and coral bells. Also, interplanting with perennials will help use up any soil moisture so the bulbs stay dry.

In Missouri, tulips and hyacinths may not come back strongly in subsequent years. Tulips are not the best perennials in Missouri, and many consider them annuals and replant new bulbs each fall. Some tulip varieties are labeled as perennial tulips and are more reliable bloomers in subsequent years. Deep planting is a must for return bloom, with bulbs planted at a depth of 8 to 10 inches. Over-watering during the hot summer months may result in the tulip bulbs rotting. It is best to plant your tulips in locations that are more dry and don’t require excess watering during summer months. Daffodils that are not blooming like they should are usually lacking enough sunshine, good nutrition or adequate moisture. Mature trees around bulbs may be providing more shade than bulbs desire. For best results, most bulbs prefer six to eight hours of sunlight per day after trees have leafed out.

Moving and dividing flowering bulbs is an easy job and not harmful to the bulbs if done at the right time. The best time for digging and dividing is after the bulbs have finished blooming and the foliage is beginning to turn yellow. Be sure to either mark the bulb locations, or dig while foliage is still visible so bulbs can be located. A spading fork works best to loosen bulbs and prevents bruising while digging. Do not let the bulbs lie in the hot sun after they have been dug. Bulbs can be planted in a new location the same day as digging. If you desire to wait until fall to plant bulbs, dry them as quickly as possible and store throughout the summer in an area that is dry, cool and well-ventilated. Bulbs may be divided by removing splits from the mother bulb, assuming they can be separated easily. Remove old dried skin and roots. After division, plant them into the ground or store in a cool, dry location until fall planting time.

Coral bells are among many perennials that can help hide the dying foliage of bulbs

Planting indoor forced bulbs (i.e. potted daffodils and hyacinths) into the garden after they have faded is never a sure thing. Forced bulbs that have bloomed and faded indoors have been through an exhausting process and may not bloom in the garden in the next year. Crocuses and daffodils generally do well planted out after forcing indoors. Tulips and paperwhite narcissus do not readily come back and generally are not worth the trouble to plant them out. These should be enjoyed during their initial indoor bloom and then composted or tossed out. Forced hyacinths may come back in the garden, but usually not with the same full, robust blooms that they had in the first year.

Mary Kroening, Missouri Master Gardener Coordinator and UMC Horticulturalist, (573) 882-9633