Below, you will find a large chunk of text. It contains all the information you need to enjoy your maple tree for a lifetime, completely free of charge. Take a moment to go through it. With this information you’ll be on the right track. If you have any questions, feel free to contact us.
Maples in the ground
The most important thing is that your tree is not planted in boggy, wet soil, as Japanese maples will quickly die in such conditions. Choose a dry location. Plant the tree in a spot sheltered from strong winds and consider how much sun the tree can tolerate. Some varieties prefer no sun between 11 AM and 3 PM. Japanese maples thrive well on mounds or other types of raised gardens due to the good drainage in such places. They naturally grow under larger trees, and the same setting in your garden can be beneficial. Choose the best spot for your tree, and dig a large hole, preferably 2 to 3 times bigger than the pot.
The first step is ensuring proper drainage. The tree’s roots need sufficient oxygen all year round. Even a few days of excessive water can severely damage or kill a mature tree. When we plant trees ourselves, we dig a deep, narrow hole with a post auger within the planting hole. We fill this hole with gravel so that excess rainwater can drain through it. Multiple holes are also fine. Cover each hole with a piece of root cloth to prevent soil from filling up the gravel and diminishing the drainage effect.
Next, refill the hole with the original soil and, of course, the tree itself. It’s always beneficial to plant the tree slightly higher than the original ground level. You may add draining elements like gravel or perlite to the original soil (but no clay pebbles, as these retain water). You may also add about 20% peat moss to slightly acidify the soil.
For optimal results, consider adding a drainage pipe around the root ball. These pipes, available commercially, are perforated along their length. One end of the pipe should extend above ground to allow air to reach the roots. For larger plants, thick roots will emerge from the base of the main stem. These may barely stick out of the soil. Do not plant your tree any deeper than it was in the pot you purchased it in. Monitor your plant during very warm periods in the first two years: extra water may be needed. Extra care is required if you are planting in clay soil; feel free to contact us for advice.
Maples in pot
Japanese maples are ideal for growing in pots. They can remain in a pot for their entire lives, and you can experiment with finding the perfect location before planting the tree in the ground. If you practice root pruning, the tree will stay small and can remain in a smaller pot. If you want the tree to grow, you can repot, but this doesn’t need to be done every year. Remove the plant from the pot: if you see more roots than soil, it’s time for a slightly larger pot. Ideally, do this at the end of February when the buds start to swell. You can loosen the roots around the edges a bit and then repot into a slightly larger pot.
The new pot doesn’t have to be very large. Choose one that’s about 5 to 10 cm wider in diameter. Move from a 3-liter pot to a 7.5-liter pot, then to a 20-liter pot, then to a 50-liter pot, and so on. This setup can easily last you 10 years. Planting maples in pots that are too large often results in excessive moisture, which is harmful to the plant. Most importantly, the pots must drain well, and the soil mix should be airy. Ready-made mixes from garden centers are often of lower quality, even the more expensive ones. Add extra perlite to achieve a well-draining mix. For larger trees, you may prefer a specialized professional potting soil, which is available from us. Optimal growth can be achieved by placing the tree in a plastic pot that is, in turn, inside a decorative pot. This helps prevent the inner pot from overheating in summer. Both pots should have holes at the bottom to allow excess water to drain. Never put a saucer under your pot, as the roots will die from lack of oxygen after heavy rain.
Only water your tree when necessary: insert your finger into the pot, and if it feels dry up to 2-3 cm, you can water it. Lifting the pot slightly to estimate its weight can also help you judge whether water is needed. Maples prefer partial drying out (but not completely!) as this stimulates root growth. When watering, ensure that the water doesn’t just run off the sides of the pot, as this can happen when the soil shrinks due to dryness. Water slowly, and if needed, submerge the root ball in a bucket of water for half a minute if it’s hard to moisten. You may apply a layer of bark to prevent quick drying.
Potted plants can stay outside all winter. Frost is not an issue; in fact, the plants need it to enter dormancy. In the case of severe frost, it doesn’t hurt to bring the plant into a cool garage or under a carport for a night, especially if the leaves have already started to sprout (see below). But generally speaking, a maple with no leaves can stay outside in -10° or -15° Celcius without issue.
Fertilizing
Fertilizing is not necessary for trees planted in the ground. For potted trees, you may fertilize in April with a fertilizer containing a maximum of 15% nitrogen (NPK = 15-X-X), such as DCM Mix 5 or Osmocote. Do not fertilize too late: the fertilizer should be depleted by September-October. New growth would otherwise perish in winter if it hasn’t hardened off properly. Fertilize less rather than more: maples are sensitive to excessive salts. A maple purchased from us does not require fertilization for one year.
Pruning
A tree pruned annually will grow faster than one left to grow freely. Surprisingly, pruning encourages a strong growth boost. Prune your trees in late March or early April, when the buds just start to swell. Sunny weather is helpful as it allows wounds to heal quickly. The plant may bleed (sap may leak from the wound), but this is not a problem. Wound paste is not necessary. When pruning, always cut a few centimeters above a pair of buds. The branch will die back to this pair of buds. Cutting too close risks further dieback of the branch. Also, consider the direction of the remaining buds when pruning, as this determines the future growth direction, so prune as you wish the tree to grow.
Additional points of attention
- For maples, drainage is crucial: whether planted in the ground or in a pot, the soil must be airy and allow excess water to drain. Keep an eye on this and contact us if you need assistance.
- In spring, your tree, like many plants, may suffer from aphids or other insects. While this is not severe, it can look unsightly. You can combat this with biological solutions (e.g., soapy water) or remedies available for purchase.
- Be cautious of late frosts. Spring 2022 was a good example: after a couple of weeks with temperatures of 15°C or more, there was a sudden hard frost of -5°C or lower in early April. At that point, the trees had already produced young leaves, and such a late frost can be harmful. The trees will recover, but this shock can be too much for young plants recently planted. Protect your plants with fleece, which is available at garden stores.
- Our Japanese maples are grafted onto a rootstock, as is also the case with fruit trees. This way, you get a strong root system of a "wild" Japanese maple, but above ground, you get the beautiful genetic variation linked to the specific variety, such as a particular color, leaf shape, or growth habit. It’s possible that shoots will try to grow from below the grafting point. Simply remove these by hand. If they have become very thick, it’s better to use pruning shears.
- Finally, remember to enjoy your tree. Take pictures and send them to us (or tag us on Instagram) so we can share in the experience.