Winter is a good time to research and then plant trees

I had a coworker recently ask me when a good time to plant trees is. Happily, now through February or March is a great time. The soil is still warm enough here (aka not frozen all winter like up north) that little roots can form and the tree (or any other perennial) can get settled in, without the stress of also supporting leaves.

I’m going to talk about what species and varieties and their ecosystem roles, and not really cover how to plant or how close to plant together. In the wild, trees grow a lot closer together than you might think from seeing trees in parks and urban/suburban settings. For domesticated trees like fruit trees, look up alternative planting arrangements to limit the size of the trees (we planted ours close together to keep them smaller, for example). For native trees, consider how they grow in the wild. If you’re not sure or don’t know what they look like in the wild, feel free to leave a comment and I’ll try to help!

Fruit trees

The extension service has the most current and useful info on growing fruit trees here. These are usually very “domesticated” plants that need to be carefully matched to the location and local disease conditions. I am a lazy (and ecologically friendly) gardener who doesn’t want to spray for diseases, so I pick disease-resistant varieties.

Something else to consider is that most apples and pears and such domestic are grafted onto a rootstock. So you want to research a good rootstock of the size you want, then select the fruiting branch stock based on its vulnerabilities and advantages. We have a small sunny area in the yard and I didn’t want it shaded out completely, so I chose dwarf trees and prune them twice a year to maintain their small stature.

Generally around now is a good time to order or pre-order bare root or potted fruit trees and then the company will ship them when they feel is the correct time for your zone.

For what it’s worth, here’s what I’ve tried in my yard.

• Apples: beware of cedar apple rust. There are cedars everywhere, so your tree will be vulnerable. I had a golden delicious and it immediately fell victim to this. I removed it. I have not had any rust problems on my William’s Pride (has already produced even though the tree is still very young), Arkansas Black (requires not one but TWO different varieties present to pollinate), Granny Smith, McIntosh (pushing its limit with our summer heat), and Liberty (cousin of McIntosh, also pushing it with summer heat). Watch for other diseases and also for summer heat tolerance as well as the winter “chill hours” required to set fruit. Stark Bros and Orange Pippin websites are good for this info.
• Pears: I got Seckel and Kieffer, both supposed to be heirloom southern varieties (ie adapted to our heat and pear diseases). Mom knows about a very old big pear tree on the grasslands at home. That tree has a perfect combination of juicy and crisp. Fruits ugly as sin, but delicious to my taste. I think from the descriptions of the varieties, it could be a Kieffer. Fingers crossed. I chose Seckel because a coworker gave me some from the local farmer’s market and they were very tasty.
• Sour cherries: they died when I planted them in containers, but I think this is because I didn’t water them enough for their fully-westward exposure. The extension service says sweet cherries struggle here so I didn’t even try.
• Honeyberries: I probably should have watered them more. They died. Oops. Usually even drought-resilient things need more tender care when first planted, and I moved these twice due to the geothermal pipe install. Sorry lil tree buddies.
• Peach: I got a dwarf variety. It has fruited, but none have matured yet.
• Apricot: I had a volunteer in my backyard in grad school in northeast Norman, and out of six years, it had fruit two years. Only one of those years was enough fruit to do anything. Apricots (and I’m told peaches) just keep getting got by our spring freezes. So, if you really like them, worth the wait. Also, the flowers are pretty. If you want spring flowers, it’s a non-invasive alternative to a Bradford/callery pear (see below for Big No-No’s section). The fruit is a nice bonus.

I’ve thought about trying Russian pomegranates and figs as well, but the figs I want (Persian figs) seem like they need too much winter care at our current freezing zone. the minor details of time and space are all that’s keeping me from Russian pomegranates. I’m too lazy to take a tree in a pot in and out of the house in the winter. (some people do that for Meyer Lemons, figs, etc.)

Native trees

The extension service does have a nice list of native-to-the-US deciduous trees. Native to the US is better than not, for ecosystem services. But if you want to maximize local wildlife value, then I suggest picking a species from Oklahoma or a nearby state that would be naturally found outside your town. (Wildlife here doesn’t have to mean deer and turkeys, this includes songbirds that need food and insects and little pollinators that need host plants and such too.)

Well-adapted vs wildlife friendly vs native

Native trees will support, on the balance, more of our local ecosystem than any given “well-adapted tree”. A tree can do very well in our climatic conditions, but if it doesn’t have the long history of being nibbled on, the local insects and other wildlife may not be able to use it as much because it can be too tough/too many defensive chemicals/too whatever for them to use it. Even plants in the same genus from somewhere far away are usually not as useful to local friends as the local species is. Nibbles and chomps and bites on your plants is a GOOD THING. It means you are part of the local ecosystem! And when your yard (and if we’re lucky, neighborhood) is not a monoculture, you’re unlikely to have everything wiped out.

So, where possible look for the terminology native over well-adapted, which can include species from far away without that value to local ecosystems. If your nursery or arborist suggests a well-adapted tree, you can ask them to suggest a native alternative. We have found that the Tree Wizard in Norman OK has been good about knowing which trees are native or not, regionally or not, and for wildlife or whatever your priority is, if you specify that’s what you’re looking for.

A really lovely book to understand the importance of keystone plants is The Nature of Oaks by Doug Tallamy. Oaks are not the only keystone species: you can also take a look at keystone plant lists such as this one compiled by the National Wildlife Federation for keystone native trees. My opinions on the trees on the NWF list for the great plains, rearranged to be alphabetical.

• Acer – maples. there are so many non-native maples sold – stick to our native ones! Box elder is a smaller and fast-growing one. The young ones have leaves that give a passing resemblance to poison ivy so don’t be alarmed. They’re still a maple. I see a lot of box elders near creeks here so they do well here. The extension site notes sugar maples, which are native to the US, tend to damage easily, but I do see a LOT of people planting them for their fall color. Also maybe you could get syrup???
• Castanea – chestnut. Goodness, but American chestnuts are an epic tale of loss and maybe hope. They might work here. They might not. Here is a potential source, courtesy of the Tree Wizard, though she has not tried this source yet either.
• Carya (pecans, hickories) – delicious nuts! More of a riparian zone tree – they seem to do well in our south-of-main neighborhood in Norman. Walking over the shells on sidewalks is sort of hazardous so probably don’t put one right by a sidewalk unless you plan to sweep all the time.
• Cornus – dogwood. The eastern flowering dogwood is a classic with its beautiful flowers, but east = rain, again. Probably don’t do this one if you’re on the higher/clay/drier end of town, but there is one in my neighborhood south of Lindsay that does alright. Rough-leaf dogwood is more of an understory shrub/tree and tends to have multiple stems and spread, which can be great or not depending on what you want.
• Fraxinus – ashes. Two species are native to this part of Oklahoma.
• Juglans – black walnut – only certain plants can grow under it. You can also make ink.
• Malus – prairie crabapple is here theoretically; I haven’t seen one before. This is also the genus for apples and crabapples. Although related non-native species usually don’t get as many critters using them, crapapples are a great pollinator for apple varieties so you can do double duty with them. However, cedar apple rust tends to get this species too. It’s unclear to me if it tends to kill the tree or just reduces production of fruits, and if the native crabapples are big enough to juice like even a small domestic crabapple like our neighbors have.
• Pinus – BONAP has two species (loblolly and shortleaf) as recorded in Cleveland County, and Zach has helpfully let me know there are wild ones near Lake Thunderbird. So, they’re here, but we’re definitely at the range edge.
• Populus – cottonwoods. The extension service recommends against these in town: “Grows too big for a typical landscape. Over time roots grow on the surface. Fast growing, weak wooded, messy”. They are really, really common and sprout everywhere, so this is certainly less of a need to have more in the ecosystem. Maybe don’t put one next to a house or sidewalk or any underground water lines? But if you have a bit of acreage and some pops up around your pond and you want it, sure.
• Prunus (plums and cherries) – Mexican plum is a great understory or near forest edge tree. This genus also includes a lot of shrubs like the spreading sand plum. Again, the domesticated ones may not do as well for local insects but if you want plums or cherries, I’m all about food too. Have both if you have space!
• Ulmus – elm – beware the non-native species easily available.
• Salix – willow – make sure it’s a native one and that it will get enough water.
• Maybe’s… but less likely to be successful without luck and/or care.
  • Amelanchier – serviceberry – Mostly out of range. A. arborea might work but possibly more eastern/wetter. I’ve never seen it in the wild around here.
  • Betula – I’ve heard about people with river birches here in Norman, but it sounds like they need a bit more water than we usually get. I wouldn’t do this unless you’re right next to a creek.
• Suggestions for the Great Plains that aren’t suitable in our part of the Great Plains. The Great Plains is everywhere from Canada to Texas! It’s a long way! You probably have seen spruces and pines around town, but most/many of the evergreens recommended by the extension service for this area are not native. Even if they are from the continental US overall, they won’t have a big community of creatures they can support here.
  • Alnus – alders – sure it’s in the Great Plains, but farther east than Norman and much farther west)
  • Abies – fir – we are too far east for these conifers to have a lot of ecosystem friends nearby to use them. No records for Oklahoma in the wild according to BONAP.
  • Larix – larch – waaaaaaay too far south
  • Picea – spruce – too far south and east
  • Corylus – hazel – all east and north of us, I wouldn’t try it.
  • Pseudotsuga – douglas fir – too far east.

So, from this list and personal observation, if you wanted to imitate a typical woodland around here in most of Norman (19 “clayey and humus rich soils” in this OGS map), a mix of oaks, hackberries, elms, pecans/hickories, ash, and boxelder would be the main big trees. Closer to the river (south part of town) add in walnuts, Kentucky coffeetree, sweetgum (watch out for the evil spiky seed balls – goldfinches love them, feet hate them, also a host plant for Luna Moths), and Catalpa. Native locusts are nice but some have nasty nasty thorns. Maybe leave those in the wild unless you can find one without thorns (people do grow them).

Typical understory/edge trees would be eastern redbud (very common all over town!), soapberries (beware similarity to the invasive chinaberry), common eastern persimmon, Mexican plum, sand plum (a big spreader, have space for it and be prepared to cut/mow with brush-cutter if it gets to full size), rough-leaf dogwood, American beautyberry (more of a large shrub), sumac (at edges, also spreads by shoots, more of a shrub??), yaupon and possumhaw hollies, Carolina Buckthorn, elderberry (also closer to a shrub and spreads by suckers), and Texas Buckeye. Willows are a pond or floodplain thing around here.

If you’re on that red, red Garber sandstone (home of rose rocks!) east of town (labeled 21 – “sandy shallow and acidic” in the OGS map), make your oaks post oak and blackjack. Save pecans/hickories/boxelder etc for riparian (creek or river) edges and floodplains.

That’s all from my memory and asking a few people their thoughts – you can also look at plant lists for the area. Mom sent me this page from NPSOT listing the trees of Denton County TX (item 11, Trees Native to Denton County). They’re directly south of us, so watch out for a few too-far-south trees, but everything else should be in a similar rainfall zone to us.

Hackberries: not on the list, nicer than you think, and you can probably get one for free

When I asked her for feedback, Mom reminded me that hackberries support a LOT of wildlife, not just pollinators, and she finds a lot of caterpillars on them. They are less well-loved sometimes but they can be really nice trees. She has a lovely blog post on some critters she finds on them at home in NC TX. I’m surprised they didn’t make the NWF list but every part of the ecosystem is important. The “most host plants” or “keystone species” lists don’t cover everything, they emphasize species that you can start with to get the most impact with the least effort. (And you all know I love low effort! Laziness is the mother of invention!)

You can buy hackberries, but you can also just plant some or find a seedling in your yard. Happily, their seed leaves are very distinctive and they are supposed to be easy to start from seed.

Big no-no’s: disruptive human-introduced species

PLEASE DO NOT PLANT BRADFORD/CALLERY PEARS. They break easily, don’t provide wildlife value, and have become invasive (I see a lot in Saxon park, for example). Regular actual fruiting pear trees are fine! Even the extension service notes:

“Pear, Callery cultivars (Pyrus calleryana) Very tolerant of soil types and drought conditions and has excellent spring flowers and fall color. However, branching structure, especially of Bradford is poor, resulting in storm damage as it ages. Cross pollination of Callery pear cultivars and the species results in fruit, which has put this tree on the invasive species watch list. Consult with retailer to consider appropriate ornamental pears for specific needs.”

https://extension.okstate.edu/fact-sheets/selecting-deciduous-trees-for-oklahoma.html#undesirable-trees

DO NOT PLANT PRIVETS PLEASE!!! Privets are a huge problem too. And, aggravatingly, major garden resources are still recommending them (I found This Old House and Southern Living both recommending them for hedges online in a quick search, just as examples). Sometimes non-native garden plants are just sort of useless – they don’t harm anything but they don’t contribute. Privets are actively harmful and will degrade even undisturbed sites.

Tree-of-heaven is another aggressive human-introduced (non-native) species that can disrupt even otherwise undisturbed sites. Interestingly, that fact seems to have caught on more around the web. All the first page results I got in searching tree of heaven in duckduckgo were about its invasive habits and not to use it. (Not at all what I got when I searched privet in the previous paragraph.)

Crepe myrtles are a small decorative flowering tree you see blooming all summer around Norman. I thought they were just boring, not invasive, but apparently in some regions they also become a big problem. This site has a nice list of native alternatives for a variety of conditions and flower colors.

If you have a non-native favorite tree you want to play for whatever reason, please search for its common name and “invasive” in your favorite search engine. Once you have the common name, try the scientific name and “invasive” together as well.

Native fruit trees

But Claire, aren’t some native species also fruiting and edible by humans? Yes they are! Some also have non-native counterparts, non-native domestic varieties, and domesticated cultivars of natives (“nativars”), so do your research before you decide what is best for your needs. Texas (south of here) and Common Eastern Persimmon, Mexican Plum, Pawpaws (tend to be east, but I see people planting them here in Norman and I think they’re still alive?), and elderberries (really more of a big shrub??) are probably the three big ones I can think of off-hand. Many of the other native trees do have edible parts (redbud flowers, nuts on various species, sumac berries, yaupon holly leaves, the spring fruits of the elms apparently, and lots more if you’re willing to research and process).

Understory trees and shrubs

I’ve been mostly focusing on big trees so I’ve probably missed some shrub-like friends who make great understory plants or edge plants or hedges or bushes. Things like the native currants, elbowbush, and so on. I’ve mentioned others up in the section about what a typical woodland looks like around Norman.

Acknowledgements

Thanks to Mary (hi Mom!), Paula, and Zach for their feedback and ideas for this post. Any mistakes are mine. Comments, suggestions, and additions are welcome!