Can You Grow a Speckled Alder From Cuttings?

Type of Cutting

• Cuttings are classified as herbaceous, softwood, semi-hardwood, hardwood and root. The best cuttings to propagate the speckled alder are softwood, taken in early summer. Softwood cuttings come from new growth, at that stage of development when it isn’t so soft it keels over when held upright but also isn't approaching woodiness. If the softwood cutting is limp, it is too young and you should choose another.

Taking the Cutting

• Take a 2- to 5-inch cutting from new growth on the speckled alder. Cuttings taken from the tips of branches root more successfully, as do those with several nodes. Softwood cuttings lose moisture quickly, so plan on taking a moist paper towels and a plastic bag with you when you go to take the cutting. Immediately after cutting it from the tree, wrap the cut end of the stem in the moist paper towel and enclose it in the bag. Keep it out of direct sun so it retains its moisture.

Preparation

• Use a sharp razor blade or scalpel to create a 1/2-inch-long wound, running from the bottom of the cutting toward the tip, on the cutting. Wounding the cutting exposes cells to the rooting hormone. Dip the cut end of the stem into water so the bottom 1 inch of it is wet and then roll that end in rooting hormone talc. Horticulturist Michael Dirr, in his book "The Reference Manual of Woody Plant Propagation," suggests 65 percent of speckled alder cuttings rooted successfully when treated with 8,000 parts per million indole-3-butyric acid powder, while only 2 percent of untreated cuttings rooted. Avoid contaminating the hormone powder in the jar by pouring a small amount into a shallow bowl or plate. Discard the unused talc after using it on the speckled alder.

Planting

• You’ll need to plant the speckled alder cutting immediately after treating it with hormone powder, so prepare a container the evening before taking the cutting. The best medium is composed of 1 part peat moss and 3 parts sand. This combination allows for fast drainage but tends to hold just enough moisture for the cutting. Drench the planting medium until it is saturated and set it aside to drain. By the time you return with the cutting, the planting medium should have drained most of the moisture and be slightly moist. Use your finger or a pencil to make a planting hole. After applying the rooting hormone, stick the cutting into the hole and pack the soil around it. The cutting will produce roots at the nodes, so make sure at least two or three nodes are buried.

Misting

• Speckled alder cuttings root successfully under mist. You probably don't have an intermittent misting system, but you can use other methods. Use an old aquarium, turned upside down over the propagation flat, or place the potted cutting in a plastic bag and keep it out of the sun. Make sure no part of the cutting touches the plastic or it will rot. One way to do this is to place chopsticks in the soil at the inside perimeter of the pot to hold the plastic away from the cutting.

Care during Rooting

• To avoid rotting the cutting, keep the soil temperature between 65 and 75 degrees Fahrenheit. You can do this by placing the propagation container on a heat mat. After about six weeks, give the cutting a gentle tug. If it doesn’t move, it has most likely produced roots. At this point, the speckled alder cutting needs to become accustomed to normal growing conditions, so begin gradually lowering the temperature of the heat mat and open the plastic bag for longer periods every day, over the course of two weeks. After this, the cutting is ready to be planted into a larger pot or into the garden.