How to Grow and Care for 'Crimson King' Maple

The 'Crimson King' Norway maple is a colorful cultivar of the much-maligned Norway maple, with many of the same issues. A medium-sized tree with attractive dark red to purple foliage that lasts until the summer's end can make for a nice ornamental tree. Though beautiful and with a form that makes a lovely specimen or shade tree in a large landscape, it has many issues that should be considered before choosing it for a landscape project. Without considering the potential for invasiveness and the fact that there are better alternatives that are native, there are some serious downsides to consider before planting one that can affect your property.

It is a pretty tree, but for the number of issues it faces, you would be better off looking towards other native maple varieties or even Japanese maples as alternatives.

Crimson King Norway Maple Care

One of the biggest red flags to consider when adding Crimson King Norway maple is the amount of care needed or the potential for maintenance it can cause. It is, like most maples, a tree that can be somewhat untidy. It will shed its samaras in the spring, the source of the mess and its notorious reputation for being weedy and invasive. These wind-carried seeds, which many call helicopters, will spread far and wide, germinating readily and causing this non-native to naturalize. The environmental damage is considerable, but consider that Crimson King Norway maple has a shallow root system, is susceptible to breakage in winter, and is vulnerable to several types of root rot. The plentiful seeds can create issues that might haunt you for a few years.

The best advice for garden owners looking to add a Crimson King Norway maple to their yard is to look at a different tree. For those who already have one or have already pulled the trigger, giving the tree the best conditions to stay healthy will keep it from causing pricey infrastructure issues. Below you will find a few tips on how to keep your Crimson King Norway maple happy and hopefully healthy.

Light

A Crimson King Norway maple can tolerate full to part shade but will perform best in full sun. You will notice the best colors and most foliage if the tree is located in an area with at least six hours of indirect sunlight daily. If placed in the part shade, there will not be any major health issues, but you will notice a definite fall off in vibrance and foliage.

Soil

One of the things that makes the Crimson King Norway maple so problematic is how easily it spreads and thrives. That has a lot to do with the fact that it tolerates a wide range of soils. If the soil is fairly average, has medium moisture, and drains well, Acer platanoides 'Crimson King' will thrive. The only soil where it will have a tough time is poor draining soil.

 Water

Once established, Crimson King Norway Maples do not require supplemental irrigation and will do fine even in drought conditions. Getting the tree to that point will take some routine watering, but it is not a chore you need to be obsessive about like you would with many ornamental trees. Giving the ground around it one good soaking a week for the first season or two should be plenty to get it on its way to being a happy and healthy tree.

Temperature and Humidity

The Crimson King Norway maple is a non-native that has naturalized throughout the Northeast and upper midwest of the United States. It thrives in the temperate climates found in those locales and does not do well in areas that get much warmer or cooler. During winter, its relatively weak wood is prone to breakage under ice and wind stress. In the summer, high heat combined with harsh sun and high winds can lead to leaf scorch. Being so vulnerable to issues caused by temperature means that the Crimson King Norway maple should stay safely put within its recommended USDA habitable zone.

Fertilizer

There is no real need to fertilize a Crimson King Norway maple in a landscape setting as it will grow with vigor in even soils that are not the best quality. If you decide to give it a bit of fertilizer, look towards using a fertilizer with a high N value in the NPK formulation, as that will help aid foliage production, which is what you are going for when growing Crimson King Norway maple.

Types of 'Crimson King' Norway Maple

Acer platanoides 'Crimson King' is itself a cultivar of the Norway Maple, meaning there will be no other cultivars of the Crimson King Norway maple. If you are looking for trees similar but with different forms or sizes, you may want to consider one of the many Japanese maple varieties.

Pruning

Pruning a healthy Crimson King Norway maple is not necessary. If your tree is thriving, has a good form (single main leader), and has no damaged branches, it can be left alone. If the need should arise, the best time to prune a Crimson King Norway maple is winter or early spring when the tree is still dormant.

Propagating Crimson King Maple

There are a few quick and easy methods of propagating a Crimson King Norway maple. The easiest is to find a re-seeded seedling, transplant it into a pot, and allow it to develop a heartier root system until you are ready to transplant it at its permanent location. The second is almost as easy; it requires more time and effort. This method will have you collect the samaras (helicopters) and remove the wings to expose the seed. Plant the seed in a pot of moist soil or starting medium, keep it moist for a few months, and wait. To ensure success, plant more than one, as you may not get 100% germination. Allow the seedlings to develop a healthy root system in the pot, and then transplant them to their final location, and you are all set.

Common Pests & Plant Diseases

Besides their invasiveness, another reason why Norway maples are often avoided is their tendency to be bothered by disease. The various root rots are the most serious diseases and types that can cause the most damage to property and cause serious injury if not remedied. With root rot prevention is key, the Norway maple suffers from three varieties, Fomes root rot, Ganoderma root rot, and Laetiporus root rot, each having different symptoms.

With Fomes root rot, you will notice a structure that is shaped somewhat like a hoof, the color will be grey, and it will be roughly about six inches long or so, growing yearly. As the disease progresses, branches will start to decay and drop, which is where the danger exists.

Ganoderma root rot is a devastating disease that will first appear as shelf-like fungi that might appear as one or a cluster that will overlap. The fungi will be an ochre color with cream borders and be roughly a foot in length. Once infected, the branches will start to die, and then eventually, so will the entire tree.

Finally, the symptoms of Laetiporus root rot will present with huge clusters of vividly colored orange shelf-like fungi that form during the late summer through early autumn. These masses will harden and fall off during the cold winter months to only form the following year again.

Sadly with all three of these diseases, once the symptoms are seen, the damage is already done, and the tree cannot be saved. Dead branches should be removed, and eventually, the entire tree, as it will, in time, fall, and it is better to have it fall on your terms than randomly, possibly injuring someone or damaging property.

Preventing root rot of all types is best done by not overwatering and planting in areas with adequate drainage.