Extension News

Ask the ISU Extension Garden Experts: Shade Perennials and Tree Grafting

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.


What are some good native perennials for a shady site?

When selecting plants for the shade garden, one group of plants that is often overlooked is native woodland wildflowers. Since they are native to the state, woodland wildflowers are well adapted to the area. They are easy to grow and perform well when given a suitable environment.

Native woodland wildflowers that make good additions to the home landscape include wild columbine (Aquilegia canadensis), Jack-in-the-pulpit (Arisaema triphyllum), goat’s beard (Aruncus dioicus), Canadian wild ginger (Asarum canadense), Dutchman’s breeches (Dicentra cucullaria), shooting star (Dodecatheon meadia), Virginia bluebells (Mertensia virginica), woodland phlox (Phlox divaricata), May apple (Podophyllum peltatum), Solomon’s seal (Polygonatum biflorum), bloodroot (Sanguinaria canadensis), false Solomon’s seal (Smilacina racemosa), merrybells (Uvularia grandiflora) and others.

Obtaining plants is easy. Woodland wildflowers are readily available at garden centers and mail-order nurseries. Do not remove plants from natural woodland areas.

I have an old apple tree that is starting to decline. I don’t know the variety, but would like another tree. How can I propagate it?

Apple trees don’t come true from seed. Grafting is the best way to propagate an apple tree. Grafted apple trees produce fruit that are identical to their parent.

Grafting is the joining together of two plant parts (scion and stock) in such a way that they unite and become one plant. When grafting fruit trees, the scion is a portion of a twig taken from the desired tree or variety. It comprises the upper portion of the graft and develops into the fruit producing branches of the new tree. The stock (rootstock) is the lower portion of the graft. The stock becomes the root system of the grafted plant.

Whip and tongue grafting is a relatively easy way to propagate an apple tree. This type of graft is made when the stock and scion are dormant. The stock and scion should be the same diameter, preferably between 1/4 and 1/2 inch. Scion material should be collected when fully dormant (February or early March) from the previous year’s growth. If possible, collect the scion wood when the temperature is above freezing. Place the scion wood in a plastic bag containing moist sphagnum moss or sawdust. Store the scions in the refrigerator until it’s time for grafting. Rootstock material can be obtained from a small number of mail-order nurseries. Both standard and dwarfing rootstocks are available.
The first step in whip and tongue grafting is to make a smooth diagonal cut through the stock one to two inches long. Use a sharp knife to insure a smooth, even cut. Starting about one-third of the way down from the pointed end, make a second downward cut into the stock to form a tongue. The second cut should be 1/2 to one inch long, slanted toward the base of the first cut. Using the middle portion of the scion wood, prepare the scion in the same manner as the stock. The stock and scion are then slipped together, the tongues interlocking. Next, wrap the stock and scion firmly together with grafting tape or 1/2 inch wide masking tape. Cut the scion off about three to four inches above the graft. There should be two or three buds on the remaining portion of the scion wood. Finally, cover the graft union area and cut end (top) of the scion with grafting wax or similar material.

If whip and tongue grafting is done in early March when the ground is still frozen, place the grafted trees in a plastic bag containing moist sphagnum moss and leave them at room temperature for seven to 10 days. Then place them in the refrigerator until the trees can be planted outdoors. Trees grafted after the soil has become workable can be planted outdoors immediately. Home gardeners may want to grow the small grafted trees in the garden for one or two years before transplanting them to their permanent site.


Contacts :

Richard Jauron, Horticulture, (515) 294-1871, rjauron@iastate.edu 

Del Marks, Extension Communications and External Relations, (515) 294-9807, delmarks@iastate.edu