Trees for the Valley

Frosty Boxelder

I frequently get asked when people want to plant a tree; What’s the best tree? What gives the best color? I want something different. I don’t want something ‘messy’. Whats your favorite tree? What will grow around here? All great questions, and every time I give just about the same answer. “It depends on what you want the tree to do for you and what your soil conditions are.”

Now I know the “it depends” answers are never a favorite, but unfortunately there is no silver bullet answer or perfect tree. With any plant, it can only be as good as the soil in which it grows and the placement of the tree in your yard. The Red River Valley (RRV) of north-west Minnesota and eastern North Dakota is a unique area when trying to grow trees. Historically, it was the lake bed of Glacial Lake Agassiz. Because of this, the soils in the valley are not like anywhere else I have seen. They are very heavy, black, nutrient rich, very high pH and all around not conducive in growing a lot of trees. Now this doesn’t mean we can’t grow trees, obviously, but it can make it challenging with some species and when starting to grow young trees.

Without getting into great detail (I’ll do that later in another blog), the RRV soils make it so vibrant fall color is often a rarity and our species selection is limited. The valley soils hold moisture very well and often times is too wet for some species. For other species the soil pH is too high and limits certain nutrients the trees need to grow and thrive. There are some other reasons, the those are the most common.

There is also a misconception that trees are hard to grown in our area because of the cold harsh winters. It is not the cold, its the soil. You can travel not that far east into northern minnesota and run into a lot of other species of trees that grow just fine in the cold harsh winters, but try them in the valley soils, and they will suffer.

So with that the following is a list of trees that I feel are the best for variety, interesting characteristics, and hardiness for the RRV:

Northern Acclaim Honeylocust (Gleditsia tricanthose var. inermis Harve) – This has become my favorite tree for the valley. Mostly because it is very hardy and not readily planted. It is seedless and thornless so there is very little mess, and has great structure for a large shade tree for a yard. With variety being the key to a healthy urban forest, a tree in a completely different family than most trees in our area is a big plus.

Hackberry (Celtis occientalis) – This is a great native tree to the area. It commonly grows in older growth areas along the rivers. They can become great, long lived, large shade trees if given the opportunity to stay healthy. There are very few problems that affect this tree. Those that do are commonly only a nuisance, rather than a threat.

Boxelder (Acer negundo) – This tree usually gets a bad rap, but since we have a reduced species availability to the valley and we need diversity, this tree needs consideration. I feel its a great tree. Its fast growing, very few, if any disease or pest problems, and if taken care of will outlive anyone who is reading this. The only reason boxelder is undesirable is that it rarely dies after its prime age when other trees do. During its main lifetime, it is just as good as the rest. Oh, and its about the only maple tree that will grow in the valley!

American Elm (Ulmus americana) – Yup, this tree is perfect for our area, just not a ton of them. The whole reason Dutch Elm disease took hold over the entire eastern and central parts of north america is because elms where planted in a huge monoculture (you know, the elm lined streets). It was easy for DED to jump from tree to tree and devastate urban forests. The same thing will be happening with ash (since the lesson was apparently not learned), but that is another blog topic. So, if you live in an area or yard with little to no elms, then plant one (the key is ONE, maybe two if its a big yard). IF the tree is healthy and taken care of, then the chances of dutch elm disease is the same as any disease attacking any other tree.

Ironwood (Ostrya virginiana) – A native understory tree, this tree provides a difference to the landscape. Although its slower growing and not showy as far a colors, it makes up for in attracting wildlife and interest in the winter. This tree keeps its leaves throughout the winter. The leaves turn brown in the fall, but persist on the tree until spring. Also, there are virtually no disease/pest problems.

Basswood (Linden) (Tilia americana or Tilia cordata) – Any of the Basswood (also called Lindens, same thing) are a great choice for the RRV. They are fast growing and have few insect/disease issues. When they flower in early July, they can fill your yard with a sweet vanilla aroma. The little leaf linden (cordata) is a great choice for a smaller yard tree or boulevard.

Bur Oak (Quercus macrocarpa) – Again, people are often turned off by this tree because “its too slow growing”. Bur oak is an old growth tree that lives for centuries, but early on in its life (10-30years) it grows just about as fast as most of the other trees (about 1-1.5 feet per year). The same can actually be said for all trees, they grow fast when young to gain access to the sun. This tree is a native to the area, which mean little to NO disease/pest problems. Also, once its established it rarely needs any care at all and will probably outlive your great-grandchildren. A bur oak on a ND golf course was recently aged back to 1750!!! Imagine that legacy that you could pass on.

Swamp White Oak (Quercus bicolor) – A little difference species in the white oak group. A great shade tree that provides something different. The leaves on this tree stay on throughout the winter. Again, very few, if any, disease/pest problems.

White Spruce (Picea glauca) – Very few conifers (evergreens) can grow well in the RRV. This, again, has to do with the soil, but also with our weather. Its often gets too wet at times and the trees succumb to fungal diseases. The white spruce (often sold as the Black Hills Spruce) is the best option. The key to this tree is to make sure it gets adequate ventilation, so do not plant them too close together. The best thing about these is no pruning required!

There, of course, are a few other trees that we can get by with, but the ones I listed I feel are the best to start with. If you don’t already have one of the trees listed and are looking for more, think about one of these. The key to any urban forest planting is diversity, so do not plant all of one species or family of tree.