All varieties of the elm tree reproduce from seed. You can start elm trees with little to no investment, especially when you collect the seeds from a local tree. Collect the seeds at the right time, plant them after they pass through a period of hibernation and then transplant them outside to a permanent home.
Collect the seeds you wish to use for planting from a tree within a 100-mile radius of the planting site and within 90 feet of its elevation. Dan Meyers, from the Department of Forest Ecology at the University of Wisconsin, advises this since the elm trees will do better with their specific genetics to survive the climate conditions, diseases and pests of the area when they are close to the mother tree. It also helps if you can replicate the growing conditions of the soil. Place a flat tray within the drip line of the tree in the spring when the seeds are starting to fall. Check the tray often to collect the seeds before the squirrels do.
Place the elm seeds in a plastic bag filled with damp but not wet peat moss. Close the bag and place it in the back of your refrigerator so it can chill at about 39 to 45 degrees Fahrenheit. If you keep it at this temperature for several months, it will break the dormancy of the seed and allow it to germinate in the spring. This is a simulation of the outside conditions, but without the threat of pests or animals eating the seeds during the fall and winter.
Fill a plant pot with regular potting soil and dampen it with water. Remove the elm seeds from the bag in late February and plant them about a quarter of an inch deep in the potting soil. Tamp the soil gently on top of them and place the pot in a sunny spot with mild temperatures around 50 to 60 degrees Fahrenheit. If the seeds have already started sprouting, move them carefully so you do not break off the sprout.
Keep the soil damp with frequent waterings until the elm seed sends up its first leaves and then water only when the soil feels dry to the touch. Keep the seedling inside until the weather warms to above freezing, especially in the evenings.
Transplant your new elm tree to a sunny spot where the soil is not acidic, (above 6 pH). It also will help if you only plant one elm tree in an area since they are still very prone to the Dutch elm disease, especially when several trees are in one area. Give it plenty of space because the seedling will grow into a large tree of 40 to 60 feet.