A cutting of a live weeping willow stem can be used to grow a new willow tree. The stem should be planted anytime from January to March to avoid any rotting of the new roots. While willow trees can be planted in ponds or in other areas of standing water, a willow stem should be planted in an area of loose soil that is not in standing water.
Choose an area that has either partial or full sunlight. The areas should not be near any water pipes or septic tanks. Willows aggressively seek out underground water sources and will infiltrate water pipes and any other buried sources of moisture.
Till the soil down to a 12-inch depth and remove the weeds and weed seeds. Cut back any weeds that are encroaching on the area, particularly if they are taller than the willow stem.
Place a thick plastic sheet on the space and plant the willow stem through it. Polythene plant sheeting for blocking weeds is available at gardening stores and home improvement stores. It allows water through the sheeting and keeps the soil moist. The sheeting should remain around the cutting for at least one year.
Plant the stem cutting about 12 inches deep. Place it through the sheet and into the soil gently to avoid damaging the bark. The buds along the stem should be pointing upward.
Keep weeds away from the new willow tree during its first three years. The young tree can be fertilized with a nitrogen-heavy organic fertilizer. The best fertilizers for willows are 10-10-10 and 20-20-20.
Water the willow often if there is not frequent rain. Weeping willows need heavy watering regularly. If they don't receive the water they need, they might grow poorly or have discolored leaves. A heavy soaking once or twice a week will keep a willow tree healthy.