Planting Japanese Maples JMs
Planting a Japanese Maple the right way will avoid problems in the future. The best soil for your Japanese maple is a fast draining sandy loam and the worst is clay. 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 weakened and unable to ward of diseases such as Pseudomonas or Verticillium Wilt.
If you have clay soil in your area the best plan is to create a raised mound that is at least 6″ to 8″ above the clay. This will allow the roots to stay healthy above the heavy wet soil. Dig a hole in the clay about 12″ to 15″ deep and a little wider. Fill the hole with bark chips and and/or compost to keep the mixture loose. Back fill the hole until it is level with the surrounding ground. After dunking the root ball in the solution of SuperThrive [explained later in this article] carefully place it on top of the ground where you amended the soil and then pack the same amended soil around the root ball to make a slightly mounded area which can be at 3′ or 4′ across.
You may want to make a half-moon or kidney shaped mound that tapers off gently from the base of the trunk of the maple to be level with the surrounding ground. Water throughly with more SuperThrive solution and check for settling of the soil, if needed pack more soil around the trunk being careful not to bury the trunk.
Use a stake to hold the root ball in place. The wind on the leaves can rock/move the root ball and this will break the feeder roots trying to get established. Make sure the stake goes through the root ball into the soil beneath to hold it firmly in place and then tie it to the lower portion of the trunk with a flexible tape that can expand as the maple grows. After 4-6 months during the spring and summer the stake can be removed.
If you are fortunate to have rocky or regular soil and not clay, 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 maples 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 maple. I recommend using SuperThrive to prevent transplant shock and to help the roots get established. [I have been using ST for 3 years now and I am a believer].
Fill a large bucket – I use a 5 gallon one, with water and add about 1 oz of SuperThrive for 4-5 gallons of water. After dunking the root ball into the ST solution, plant your maple and pour the remaining mixture over the root ball. The soil will settle so add more soil until the crown of the trunk is level with the surrounding ground. Water once a week during the hottest summer months. When cooler weather prevails you can water every 2-3 weeks and then once a month. 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. You can water a little more often during the hottest months of the summer.
Please remember that nearly every JM shows a little leaf burn during the first summer. It is OK, do not over water. Leaf burn can also happen if you have too much sun on a maple that needs shade in the afternoon – so make sure you are planting the JM in the right spot for it to thrive. Watering deep with a drip system or hand watering using a hose that is left to gradually spread water over the root ball 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. If planting in the fall or winter reduce watering or don’t water at all because of rain and the fact that the maple is dormant and does not need more water. Do not over water!
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. The container must have drainage holes then add a small amount of gravel at the bottom to help with drainage. Again the soil mix 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 variegation if over fertilized. A slow-release fertilizer, such as Osmocote, is recommended. Do not use potting mix that has fertilizer in it when first planting your maple. Fertilize once in the spring for your container grown maples. When planted in the ground maples do not need any fertilizer. 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 – Planting Japanese Maples – please call or email me.
Sam, the Maple Lady.