Five small tough maple trees for your garden

Once upon a time when lots were big, we could plant large growing shade trees.  As house lots have gotten smaller, big trees just don’t fit into the landscape very well. Smaller trees that are attractive and tough are what many people are looking for. With that in mind, here are five different types of small maples that are suitable for yards and as street trees where power lines preclude using large trees.

Tridant maple, Acer buergeranum

Photo credit:  Pat Breen Oregon State University

This tree gets about 20 ft tall and wide and is adaptable to urban environments. As an added feature it has red and orange fall color

Hedge maple, Acer campestre

Photo credit:  Pat Breen Oregon State University

Hedge maple gets about 30 ft tall and wide, has a medium growth rate and is long lived. It has a reputation for being tough and for tolerating urban conditions. As it ages, it develops corky bark. Leaves turn yellow in fall. Cultivars include Carnival, Metro Gold, and Queen Elizabeth.

Flame maple, Acer ginnala 'Flame'

Photo credit:  Pat Breen Oregon State University

Another small maple rarely getting larger than 20 ft. tall and wide, this is one of the hardiest trees available. Specimens are very interesting in form because of their spreading branch pattern. Flame is a seed source selection, chosen for improved form and consistent brilliant orange-red-deep red fall color. 

Paperbark maple, Acer griseum 

Photo credit:  Pat Breen Oregon State University

A tree of rare beauty, this trifoliate maple's compound leaves give it a delicate texture in summer, then long lasting red fall color. Exfoliating orange-brown to cinnamon-brown bark creates year round interest. It rarely gets more than 25 ft tall and 20 ft wide. This is a true specimen tree.

Japanese maple, Acer palmatum 

Photo credit:  Pat Breen Oregon State University

The seedling Japanese maple is tougher than nearly all named varieties. It has fine textured foliage and a light airy appearance. It is generally faster growing and adapts to more difficult environments than the hundreds of cultivars which are derived from it. Fall color ranges from yellow to orange to orange-red. Size is variable but rarely gets larger than 20 feet tall and wide.

Written By Tom Cook, City Beautification and Urban Forestry (CBUF)

A CBUF Guide to Caring for Your Trees

About your new trees:

A CBUF* guide to caring for your street trees

*Civic Beautification and Urban Forestry advisory committee

The first part has been completed and your new trees are in the ground. If you do the following you can insure that your trees will survive and thrive.

Water: Later in the spring city parks staff will attach water bags to your tree. All you need to do is fill the bags up once per week starting in May and continuing through Labor Day. Research shows that trees that are watered regularly for the first three summers after planting have better growth and survival than trees that are not watered. By the end of the third summer the city staff will remove the water bags and you can let the trees fend for themselves.

Water bags are pretty tough but they do need some maintenance. They are designed with tiny holes in the base of the bag to allow water to ooze out over a period of hours. Often by the end of summer algae growth inside the bag may plug the holes and water will not empty out of the bag. If this happens you can poke three or four new holes in the bottom of the bag using a small diameter nail. 

Water bags sometimes develop unwanted holes and lose water too fast. If you see large leaks they can be sealed reasonably well by applying duct tape over the leaky spot. Make sure the bag surface is clean and dry before applying the tape.

Water bags hold about 20 gallons of water. Place a hose in the slit at the top of the bag and let it run until the bag overflows. Weekly watering from Memorial Day through Labor Day is the goal. If you forget to water just start again when you remember. In very dry springs and the first spring after planting, you may have to start watering in early May.

Mulch and weed: At the time of planting, the trees are mulched with wood chips to help conserve soil moisture and allow early root growth to occur without competition from grass. The mulch zone also prevents trunk damage from lawnmowers that may collide with your trees.

Your job is to maintain a grass free zone, three feet in diameter or larger, for the first three years. Regular mulching will help but hand weeding will likely be necessary at least once per year. It’s okay to apply 3” thick mulch every year but be careful not to pile mulch right at the base of the tree trunk.

If you fail to keep up with mulching and hand weeding and the grass grows around the tree trunk do not use a weed eater to remove the grass because the strings will damage the vascular tissue located just beneath the thin bark of the young trees. This will stunt tree growth and may even kill the tree if the entire stem is girdled.  Hand weeding is the preferred way to remove grass around the base of the trunk.

If you choose to apply a non-selective herbicide to kill unwanted grass, be sure to follow label directions exactly and avoid directly spraying the base of the tree trunk.

A 3-4” mulch of bark or wood chips and periodic weeding will keep the area around the base of the tree weed free. It will also create a buffer zone to keep lawnmowers from running into the trunk.

Once grass grows right up to the tree trunk, the best way to remove it is by hand. Avoid using a string trimmer because it will damage the vascular tissue located beneath the bark and stunt tree growth or even kill the tree.

                                                                                                                             

Keep an eye out for problems: Inspect your trees periodically to make sure they are healthy. If damage occurs from disease, insects, or vandalism contact the city arborist and a staff member will come out to check on your tree. Occasionally, new trees fail to leaf out or die shortly after leafing out during the first spring. If you notice this please contact the city arborist so arrangements can be made to replace the tree.

Feel free to contact your Corvallis City Forester if you have any questions or concerns: 

Jon Pywell (541-754-1723), Jonathan.Pywell@corvallisoregon.gov