How to plant and care for Japanese Maples

Discover how to plant Japanese maples (ACER palmatum) and how to care of them later on:

PLANTING of Japanese Maples

  1. Choose the right place taking into consideration sunlight : most of Japanese maples (ACER palmatum) prefer shady places (for more information on your specific maple search on our website to get all the details). To understand well “full sun”, for example, don’t be influenced by the place’s orientation (south, north, west or east). It’s the daytime period that counts. “Full sun” means in fact direct sunlight from noon until 5 pm. Avoid wet places where water stagnates in winter or summer. Japanese maples are well suited for slopes or pots.
  2. Prepare a good planting hole: for trees, conifers and shrubs, we recommend the following dimensions : 1 x 1 x 1 m. Separate the first layer of good soil and replace 50% of the bad soil below with compost. Plants need nutrition just like you! DO NOT USE any peat. It dries strongly over rainless periods and later, it is very difficult to get wet again. As a result, your plants suffer lack of water. In addition, peat seams to increase the risk of verticillium which is a dangerous disease for Japanese maples.
  3. When you fill the hole again and plant your tree, shrub or conifer, you MUST NOT put any soil or compost on top of the initial root clod. Otherwise, plant growth can slow down or stop, or the plant can die. For Japanese maples, it’s good to see a bit of the roots on the bottom of the trunk.
  4. Water well directly on the root clod (at least 12 liters).
  5. If you have any mulch, cover the planting area with it, but avoid the bottom of the trunk. This will reduce weeds and improve moisture during dry periods. DO NOT USE any cut grass and compost based on cut grass.
  6. Be aware of animal urine, especially cats and dogs. This kind of “watering” can be fatal for plants. Urine on evergreens, especially TAXUS baccata, BUXUS and conifers can have the result as systemic herbicides : it destroys the plant by starting where the first contact happened and continues through the rest of the plant. The urine of foxes and badgers can be as dangerous.
  7. If it’s a tree that you are planting, it can be useful to install a post (depending on the size of the plant). This will make your planting more stable and improves the development of new roots.

CARE for Japanese Maples

  1. Water well during at least 12 months and especially over dry periods. ATTENTION!! It can be dangerous to believe that rain brings enough water. That is often times NOT true. If you want to succeed in gardening and ensure a good watering for your plants, buy a simple rain gauge. It’s the only mean to observe the level of humidity in a garden. A rain gauge is as important as a spade or a hoe. The surveillance of a good humidity is even more significant for evergreen plants, as they show often times too late a lack of water by loosing their leaves or turning yellow or brown. And then any rescue is vain.
  2. Japanese maples get verticillium: to prevent this, spray preventively leaves and branches on a regular basis with Bordeaux-mixture (used in organic agriculture). You can diminish the dose per spraying if you increase the number of treatments. Signs of verticillium are drying ends of branches or black shadows on the branches (especially on older ones). What to do if those signs appear? You MUST immediately prune those branches until you have a clean cut, put some healing paste on the cut and spray the whole plant (leaves and branches) with Bordeaux-mixture (with a high dose).
  3. If you don’t have covered your planting area with mulch, open regularly the planting area with a hoe. Thereby, water can easily enter the soil and reach more efficiently the plant’s roots.
  4. AVOID pruning Japanese maples. If you can’t do without, prune them only the last week of may and the first of June. Afterwards, follow our instructions on the treatment of verticillium (see point 3).