Extension News

Ask the ISU Extension Gardening Experts

Note to media editors: Got gardening questions? Call the Hortline at (515) 294-3108, Monday-Friday from 10 a.m. to noon and 1 to 4:30 p.m., or e-mail us at hortline@iastate.edu. For more gardening information, visit us at Yard and Garden Online, http://www.yardandgarden.extension.iastate.edu


How do you force daffodil bulbs indoors?

To successfully force daffodils indoors, you’ll need high quality bulbs, a well-drained commercial potting mix and suitable containers. Containers for forcing can be plastic, clay, ceramic or metal. Almost any container can be used as long as it has drainage holes in the bottom.

Begin by partially filling the container with potting soil. Then place the daffodil bulbs on the soil surface. Adjust the soil level until the tops of the bulbs are even or slightly below the rim of the container. The number of bulbs to plant per pot depends on the size of the bulb and container. Typically, three to five bulbs are appropriate for a 6-inch-diameter pot. However, a 6-inch pot will usually accommodate five to seven bulbs of miniature varieties.

Once properly positioned, place additional potting soil around the bulbs. However, do not completely cover the bulbs. Allow the bulb tops (noses) to stick above the potting soil. For ease of watering, the level of the soil mix should be 1/2 to 1 inch below the rim of the container. Label each container as it is planted. Include the name of the variety and the planting date. After potting, water each container thoroughly.

In order to bloom, daffodils and other spring-flowering bulbs must be exposed to temperatures of 40 to 45 F for 12 to 16 weeks. Possible storage sites include the refrigerator, root cellar, or an outdoor trench. During cold storage, water the bulbs regularly and keep them in complete darkness.

Begin to remove the potted daffodil bulbs from cold storage once the cold requirement has been met. At this time, yellow shoots should have begun to emerge from the bulbs. Place the daffodils in a cool (50 to 60 F) location that receives low to medium light. Leave them in this area until the shoots turn green, usually four or five days. Then move them to a brightly lit, 60 to 70 F location.

Keep the plants well watered. Turn the containers regularly to promote straight, upright growth. On average, flowering should occur three to four weeks after the bulbs have been removed from cold storage. For a succession of bloom indoors, remove pots from cold storage every two weeks.

How do I care for my Christmas cactus in fall?

Day-length and temperature control the flowering of the Christmas cactus. The Christmas cactus is a short-day plant. Plants will not bloom properly if exposed to artificial light at night. Flowers also may fail to develop if the plant is exposed to temperatures above 70  F. Night temperatures of 60 to 65 F with slightly warmer daytime temperatures are ideal for flower formation. In early fall, place the Christmas cactus in a cool location that receives bright light during the day, but no artificial light at night. An unused bedroom or basement may have the proper environmental conditions.

Keep the Christmas cactus a bit on the dry side in fall. A thorough watering every seven to 10 days is usually sufficient. Continue to give the Christmas cactus good, consistent care during flower bud development. Moving the plant from one location to another, excessive watering or other changes to its care during flower bud development may cause the buds to drop off. The Christmas cactus can be moved and displayed in another room when the first flowers begin to open.

Which shrubs have colorful foliage in fall?

Deciduous shrubs that have colorful foliage in fall include the winged euonymus or burning bush (Euonymus alatus), fothergilla (Fothergilla spp.), common witchhazel (Hamamelis virginiana), Virginia sweetspire (Itea virginica), spicebush (Lindera benzoin), staghorn sumac (Rhus typhina), and blackhaw viburnum (Viburnum prunifolium).


Contacts :
Richard Jauron, Horticulture, (515) 294-1871, rjauron@iastate.edu Del Marks, Extension Communications, (515) 295-9807, delmarks@iastate.edu