The ash tree is a familiar plant, very popular with landscape gardeners who wish to have a large tree in the background of their garden, and also popular with residential estate designers and park planners.
As ash trees are so popular and abundant, it is not difficult for people to propagate their own seedlings, and this can be done in a number of ways, from the simplest, using ash tree seeds, to grow plants, to planting cuttings, and even using root grafts.
1. Propagating an Ash Tree from Seed
This is the most common way to propagate the ash tree. In fact, it is rarely necessary to propagate the tree at all, as it is self-propagating. However, it does require some care, as ash tree seeds are not always quick to germinate; they may lie dormant for many years after descending from the tree.
Other problems with using ash tree seeds for propagation is the tendency of the ash seeds to become unviable. This is due either to a lack of fertilization, or through the actions of a larvae. This pest eats the "egg" of the seed, meaning that it is just an empty shell with no capacity for germination.
The first thing to do when attempting to propagate an ash tree using seeds is to gather them from under the ash tree. When you have a suitable amount (more than a handful or two), take them back to your house, and "float" them. Ash tree seeds that float on the surface have no ova inside, and should be discarded as unviable. The ash tree seeds that sink to the bottom can now be used to grow ash plants.
As ash tree plants have a long germination period, it is important to speed up this process by stratifying them. This replicates winter-summer-winter cycles, and hastens the production of hormones that encourage germination. Place your ash tree seeds in a plastic bag, and cover with peat moss to replicate soil. Keep them in a warm room for a few days, and then place the plastic bag in the fridge. This should be left there between four weeks and three months. Take the seeds out of the fridge, and place in a warmer area, such as a linen closet. Repeat until signs of germination are visible.
2. Transplanting Sucker Branches
In older ash trees, it is common to find "sucker" branches growing up from the roots or lower trunk. Gardeners usually trim these off during pruning season, but they can be used to grow new ash trees. The best time for picking these is during the summer, between June and August. Take a newly grown sucker, and plant in a well drained pot with soil and mulch. It is possible to add a rooting hormone to encourage growth.
3. Make a Graft
This requires an ash tree root and a cutting or sucker. Cut the root so that a piece of bark peels away, insert the cutting, and wrap both with tree paper. Plant the root in soil up to the cut mark, and grow.