In the coldest part of winter, takes cuttings at least the thickness of a thumb cut into about 5" lengths. The cuttings are then placed upside down in a pail filled with sand and filled with water to the top of the sand. Keep in cool place, but frost-free. Cuttings should be planted on sites that have sufficient moisture to start and carry the cuttings through the growing season. Cuttings are best taken in the spring from dormant 2-4 year old wood. Cuttings 12"-20" long and greater than 3/8" in diameter produce best results, with the cuttings rooting freely along the entire length of the stem. Roots and shoots from cuttings can be expected to appear 10-20 days after planting. Using root cuttings and nursery-grown stock will produce the best results. In spring, little knobs on the sticks where roots will set begin to develop. This is the right time of the year to set each cutting right side up in the pot of sand and. Water. This method of propagation works not only for willows, but also for poplars, dogwoods, and other hardwoods which produce their own rooting hormones. Suitability of a species can be tested by placing a twig in water. If roots form by themselves, the species can be used.
If the soil is wet in the spring, you can stick willow branches directly into the wet ground as soon as the frost is gone out of the soil. They root more easily than any other species. One warning: Do not plant willow or poplar within 100' of a building. The roots have a big spread and thirst for water. The roots can end up plugging sewer lines. All the above hardwoods are water-loving plants and should not be planted unless the conditions are right.
Sexual reproduction: Male and female flowers borne on separate individuals. The willow species starts flowering at 2-10 years of age, with optimum seed-producing years from 10-30. Bees are the chief pollinating agents and large quantities of lightweight seed are produced and dispersed in the spring, but seeds remain viable for only a few days. These Seeds do not require a period of dormancy prior to germination, but successful establishment requires a moist, exposed mineral substrate that receives sunlight. These conditions are best on recent deposits of alluvial silts and gravels along waterways or in silted-in, abandoned beaver ponds.Vegetative reproduction will establish by root shoots and basal stem sprouting. Stem and root fragments root naturally if buried in moist soil. Damaged and cut stems produce prolific sprouts from the stem base or root collar. Layering also occurs if branches buried. The Noxious Weeds Advisory Committee will consider placing restrictions on the propagation and sale of willow trees and the removal of species in areas where they are an environmental threat.
One of the worst affected is the Bega River system where, over the past 150 years, the number of willows has grown from 2,000 to more than 2
million. In Bega, the Department of Land and Water Conservation said infestations of willows had eroded the river banks and caused flooding in some places.
Rivar' Mackenzie willow is a deciduous shrub originating from native plants growing along the the Tucannon River, near Starbuck, Washington at an elevation of 800 feet. One to two year old stems on the dormant plants have reddish-brown bark; on older stems the bark is gray. The leaves are simple, entire, alternate and average five inches long, 5/8 inch wide. The leaves are usually lanceolate with finely toothed margins. Staminate and pistillate catkins appear in the spring after the first leaves. Mature plant height is 12 feet and canopy width is 15 feet at Pullman, Washington. No disease or pest of this willow has been noted by the PMC. Willow pollen is an important food source in the spring for honeybees. 'Rivar' Mackenzie willow has a rapid growth rate and will grow in moist sands and gravel, with minor inclusions of silt loam, and requires a minimum of 20 to 25 inches annual precipitation. It is used in conservation plantings for streambank stabilization, riparian site restoration, landscaping, wildlife habitat, and shelterbelts. Other uses are for erosion control and promotion of native plant diversity.
Hardwood cuttings of 'Rivar' Mackenzie willow are available in limited quantities for increase to growers and nurseries from the Pullman Plant Materials Center. Silvar' coyote willow is a deciduous shrub originating from native plants growing along the the Tucannon River, near Starbuck, Washington at an elevation of 560
feet. Mature plant height is 22 feet and canopy width is 18 feet at Pullman, Washington. 'Silvar' is thicket forming, suckering, with pale blue-green silvery leaves and silvery pubescent twigs. The leaves are simple, entire, alternate and average four inches long, 5/16 inches wide, and are persistently hairy. Staminate and pistillate catkins appear after the first leaves. No disease or pest of this willow has been noted by the PMC. Willow pollen is an important food source in the spring for honeybees.Coyote willow grows in moist sands and gravel, with minor inclusions of sandy loam, and requires a minimum of 20 to 25 inches annual precipitation. Coyote willow will establish naturally by seed, however, the more common way is by hardwood cuttings taken in late winter.It is also used in conservation for streambank stabilization, riparian site restoration, bioengineering projects, wildlife habitat, and shelterbelts. Other uses are for erosion control and promotion of native plant diversity.
Rhizopon is an organic root treatment used to induce rooting on cuttings, and is already reported to stimulate the development of new roots on transplanted nursery stock. Rhizopon has been used on many species of ornamental plants around the world and the US distributor.
Grey mold caused by the fungus (Botrytis cinerea) is one of the most common and destructive pests of forest and conservation nurseries. Although it can also be a serious problem in bareroot nurseries in wetter climates, Botrytis blight is best known as a foliage blight and stem canker of container seedlings. If left untreated, the fungus thrives at cold temperatures, and can develop into a serious storage mold. Botrytis is a common fungus, so spores are always present in the nursery environment. The fungus typically infect weak or damaged foliar tissue when free moisture is present. In fully enclosed propagation structures, these conditions develop during the late summer and fall when seedling crown canopies close, and the lower foliage is shaded out and begins to senesce. At the same time, night temperatures are lowered for the Hardening Period, which results in moisture condensation on the foliage, especially after irrigation. The disease cycle of Botrytis is very short, and inoculum levels can build up quickly in the favorable container nursery environment. The secret to successfully controlling Botrytis is to develop an integrated program of both cultural and chemical control measures.