Planting Instructions for Japanese Maples
Planting a Japanese Maple done right. The best soil for your Japanese maple is a fast draining sandy loam. Japanese maples do not like wet feet, a term used for poor drainage. In my opinion 99% of the JMs that die are from poor drainage or root rot which can leave the maple suceptical to diseases such as Pseudomonas.
If you have clay soil in your area the best plan is to create a raised mound that is at least ten to twelve inches above the clay. This will allow the roots to stay healthy above the heavy wet soil. Amend the clay 12″ to 15″ below the surface. Include bark chips and compost to keep the soil loose. Backfill the hole until it is level with the surrounding earth. Place the JM pot on the soil where you want to plant it. Remove the pot and take away the soil in the circle made by the pot to a depth of about 4″. After soaking the root ball in SuperThrive [explained later in this ariticle]. Carefully place the root ball in the holdeand then pack the same amended soil around the root ball of the maple to make a slightly mounded area which can be at 3′ or 4′ across. You may want to make a half-moon shaped mound that tapers off gently from the base of the trunk of the maple to be level with the surrounding ground. Water throughly and check for settling of the soil and pack more soil in as needed. Because of the leaves on the maple the wind can shift the root ball which will break the feeder roots trying to get established so you need to put a stake through the root ball into the soil beneath to hold it firmly in place.
If you are fortunate to have sandy or rocky soil, dig a hole larger than the root ball and backfill the hole with mulch, bark chips or compost so that the maple, when planted, is even with the surrounding ground. When planting your maple in the ground or in a container, be careful not to disturb the root ball any more than necessary. Root bound containers will require you to loosen the roots a little.
Transplanting on a hot summer day is not recommended. Cooler weather will be less stressful on the plant. I recommend using a Vitamin B supplement or SuperThrive to prevent transplant shock. Thoroughly water the root ball with the mixture of Superthrive right after planting and then water once a week every week durng the summer time. Change to watering once a month beginning in fall. If you have rain or snow in the winter months do not water. Begin with once a month watering again in March/April depending upon your climate zone, or when the maples begin to leaf out. When temperatures rise in July and August water once every couple of weeks.
Please remember that nearly every JM shows a little leaf burn during the first summer. It is OK, do not over water. Watering deep with a drip system or letting a small sprinkler run over the root area will force the roots to go deep. Sprinkler systems that water a little every couple of days keep roots on the surface.
Very important – Do not plant the base of the trunk below the soil line. To conserve moisture and protect in the winter–use mulch or bark chips around the base of the tree. If planting in the fall or winter reduce watering because of rain. Do not overwater.
If you decide to plant your maple in a container (they make wonderful container plants), care should be taken to use a planting mix with adequate drainage so that the roots do not become water logged. A small amount of gravel at the bottom of the container can help with drainage. Again the soil should be loose, so add some bark chips to your potting mix and water as needed, depending upon time of planting.
Lastly, Japanese maples do not like a lot of fertilizer. In fact, variegated maples may even loose their color variation if over fertilized. A slow-release fertilizer, such as Osmocote, is recommended. If planted in the ground fertilize once in the spring. Do not fertilize in the fall or winter as the maple requires a dormant period, which would be jeopardized by applying fertilizer. When in doubt or if you have questions not answered in this section – please call or email me.
Sam, the Maple Lady.