All things Black Locust

Steve Thorn wrote:I soaked them in willow water overnight.

The larger branches did best. Most were probably 1/4 of an inch and the best one was the largest at about 3/4 of an inch.
. . .

Thanks for the information, Steve.

So you soaked them in water overnight, that's it. And then put them in the ground? That sounds pretty easy. I'll try that.
BTW: I watched your YouTube video mentioned in the other thread and gave it a Like.

One more question: is there a difference in cold-hardiness between different strains of Black Locust?
I am especially interested in the Frisia cultivar. Any idea if this cultivar is less cold-hardy than other varieties of Black Locust?

Thanks David. Yeah, willow water. (Water with cut up young willow branches in it.)

From what I've seen there are more cold hardy varieties. I've noticed the local black locusts seem to be more cold hardy than the one in the picture that I purchased from somewhere else. That one seems to be a faster and more healthy grower though. I bet the seedlings from it and the local varieties could have some good combined genetics. I don't have any personal growing experience with the Frisia cultivar though.

I've bought black locust seed from https://www.treeshrubseeds.com/ before but I don't see it for sale there now, might be out of season. I think it was $20-25 US for a pound, thousands of seeds. I boiled water in a cup, took it off heat, then put the seeds in and let them soak and the seeds swelled nicely, then I planted them in pots and they were 2-3 feet tall in a couple months with forgetful watering. Hoping to plant more on the lab next spring to get a grove growing for coppice and perhaps some standards for construction years down the road.

Does anyone know how a black locust will grow in zone 3 or 4?
I’d like to put some on my property but I’m unclear which zone it’s in as my property is literally on the edge of the zone map.

The native range extends about halfway up into Pennsylvania.  I've seen it growing in the high desert in Eastern Oregon, at an elevation of about 4,500' -- the USDA zone charts put that area in zone 6, but it's really not.  Winters are frequently down to thirty below (F), and the growing season is less than four months and can be quite a bit less.  That's all I can tell you -- I have a bunch of black locust trees in my back yard, but I'm in zone 6b.

I've read it's hardy to zone 4, so perhaps if you develop microclimates that make it a touch warmer that would help. Make sure there's no frost pockets, avoid north facing slopes, things like that.

Donald Smith wrote:Does anyone know how a black locust will grow in zone 3 or 4?
I’d like to put some on my property but I’m unclear which zone it’s in as my property is literally on the edge of the zone map.

I'm in zone 4b, the sands of Central WI. It is totally verboten to plant them here because they are invasive in Portage county WI. [But not in Wood County, just across the road from me. go figure! If you look at the map of zones [the detailed one] from just a few years back I was smack dab in the center of a small island of zone 3, completely surrounded by a zone 4, but zone 5 was maybe 20 miles away, so we've had a little bit of everything. With the climate warming up, I'm now squarely in zone 4b. The Arbor day foundation tells me I'm in zone 5. Looking at their catalog as to what grows in zone 5, they are way wrong however, even with protection.
Back to black locusts. 3 miles east of me, they are still in very sandy soil [great potato fields] and black locusts are considered invasive. I met a lady who had a mulberry and let  me pick them [that is where I got my 26 mulberry from seed]. She had only a small patch of black locusts and because of the thorns, she didn't want them there at all.
Long story short, she decided to eradicate them and discovered that the roots made a tangled mat. they were impossible to dig out. Next best thing, she decided was to mow systematically every sprout that came up. Big mistake! Huge! Like a number of invasive plants whose top you clip, the roots then try to escape the reach of your mower. It is like a Hydra: You cut one head and 10 sprout.
If you are a beekeeper [and that is what got me interested in black locust first, [as black locust gives a very fragrant honey that never crystallizes]. Well, I discovered from talking to other beeks that some years they love it an some years they won't touch it. We don't know why.
If you decide to grow this beautiful tree for the great fragrant racemes, make very sure that you love them and want them to grow there forever and you don't mind if they take over.
The lady I was talking about had to ask a horticulturist to come and spray the crap out of them. Not much grows in her yard anymore. She still has some stubborn locusts that pop up and she keeps some Roundup handy. She has invested in large pots to grow her tomatoes with imported soil. Her neighbor has started mowing along the fence.
Some folks still like them as living fences. If you have sandy soil, beware. Just saying...

Our soil is rather heavy; the black locusts do try to pop up around the yard, and I chop them off if the goats don't find them first.  However, within limitations, I want them, and want them to expand in one direction.  I'm going to start pollarding the young trees for a source of small firewood and for poles.  

Kathleen Sanderson wrote:Our soil is rather heavy; the black locusts do try to pop up around the yard, and I chop them off if the goats don't find them first.  However, within limitations, I want them, and want them to expand in one direction.  I'm going to start pollarding the young trees for a source of small firewood and for poles.  

It might act differently in heavy soil: [Not go quite as deep perhaps?] Goats will be working at removing them, and a few thorns will not deter the goats as they are browsers! You mention wanting them to expand "in one direction". To that effect, you might want to let them grow one year while bending them down in the direction you want them to expand. Then, in the Fall, bury / layer them: In the Spring, you will have a new plant at each node. Easy peasy! If the goats get too aggressive, you may have to protect your black locust with a fence they cannot reach through.
Good luck to you. Let us know how it turns out. [I love the smell of the black locust racemes but they are too aggressive in sand :-(

Wow, this is an extensive thread that I'll need to come back to several times to fully understand. Now I'm looking to grow some black locust at my place for it's many uses.

Cécile Stelzer Johnson wrote:

If you are a beekeeper [and that is what got me interested in black locust first, [as black locust gives a very fragrant honey that never crystallizes]. Well, I discovered from talking to other beeks that some years they love it an some years they won't touch it. We don't know why.

I am curious: how many Black Locust trees do you need to yield a significant amount of honey (say, 1 cup)?

I heard on QI that a bee averages a teaspoon of honey over it's life, but ultimately you need more than just black locust for the bees to survive year to year in a hive. You'll want to plant a diverse polyculture that includes various plants that bloom at different times of the year, so there is always something for the bees to eat. If you have enough nearby, then the bees can travel less searching for enough. So it's a matter of supporting a full hive, and leaving most of the honey for the bees to thrive.

David Binner wrote:

Cécile Stelzer Johnson wrote:

If you are a beekeeper [and that is what got me interested in black locust first, [as black locust gives a very fragrant honey that never crystallizes]. Well, I discovered from talking to other beeks that some years they love it an some years they won't touch it. We don't know why.

I am curious: how many Black Locust trees do you need to yield a significant amount of honey (say, 1 cup)?

That is pretty hard to say. There are lots of different kinds of honey. Here, where the season is short, I'm not going to disturb my bees several times to harvest a specific kind of honey, plus I do not have many hives to make such disruption pay. I just thought I'd give you a few pointers if you want to have a pollinator garden/ harvest honey.
Bees pack the nectar from one type of flower roughly in one frame at a time, starting from the bottom center, then going to a higher frame in the hive, but a frame may have many different kinds of flower nectars depending on how many blooms and the length of the season. and that is good for the bees too: their 'larder' will have many different things, enhancing their life/ sustainability, their immune system.
You have to look at the color of the frame to figure out which honey you really have, and maybe taste it to figure it out. I cringe when I see honey billed as "cranberry honey"[cranberries do not produce any nectar, so there is no such thing, but you will see some on the shelves!].
When you choose plants for a pollinator garden, There are many factors to consider:
Palatability to the bees, abundance of nectar,  taste, crystallization and super important: length of the blooming season. They eat 365 days in the year, but no flower lasts that long. You have to work for constant overlapping of blooming times. You may not want to plant acres of a flower that blooms only one week!
Buckwheat is one of my favorites because I can "time" the blooming period to coincide with a dearth of nectar in the environment. You can be pretty sure that about 70 days after planting, you will have blooms. The flavor is very rich the honey is very dark and good for a cough, but not everyone like the strong taste. [I do. That is *my* honey].
Dandelions are profuse bloomers but bees seem more interested in the pollen in the spring, when our colonies are depleted. They will also bloom twice, once in the spring and a few more blossoms can be had in the Fall, when the temperatures cool off.
Forsythias make gorgeous blooms, but bees are not interested in neither the pollen nor the nectar.
Many hybrids of other flowers are made to look pretty but you will not see a honeybee on them: they care neither for the pollen nor the nectar, or they cannot get to the nectaries because of too many petals in the way.
Black locust is in bloom 7-10 days, but depending on how dry the season is, honeybees may be interested... or not. Their interest seems to coincide with a drier season. [Could it be that they have to do more work to concentrate the nectar into honey? I don't know.] It makes a delectable, transparent honey,  and does not crystallize, which is a very good feature to any honey producer.
The common milkweed blooms from June to August, profusely and nectar availability is all day, which is an oddity: [most flowers have nectar in the morning but dry out in the afternoon. The nectar is so sweet and so abundant that if you shake the flower vigorously, droplets of nectar will fall off. The honey from it is light, with a yellow tinge, and it tastes just like the flower smells. Delicious. But if the days gets hot, the abundant nectar becomes sticky and entraps our bees. If you can water a field at night, that won't be a problem.
The Ohio Spiderwort makes a beautiful blue flower that bees really like but each flower lasts only one day. However, the many clusters last and last, so I suppose one *could* get spiderwort honey. Because there are no cultivated fields of spiderwort, I've never heard of spiderwort honey. Its nectar will be mixed with all the other nectars in the hive, and contribute to honey having a reputation as an anti-allergy substance [but only if you get local honey, from the flowers you are allergic to].
Goldenrod is a fall flower very much liked by honeybees... but the taste is horrid according to a number of beeks. Another reason to not harvest this honey: It comes as one of the very last flowers our bees can use here, so that is what they store for the winter. Let them have this honey.
If you plant rape/ canola, or if a neighbor plants some nearby, the gorgeous bright yellow fields will be a buzzing magnet for 2-3 weeks, and canola can be planted for a Spring *and* a Fall harvest, greatly increasing the yields. However, it crystalizes in the hive if not extracted as soon as capped, and then bees cannot liquify it for consumption and they will starve. You will have to destroy the combs to harvest it by melting the whole thing if you allow it to harden in the hive. It is a mess!
Basswood honey is delicious and abundant. If you can plant basswood, please do: it will greatly help your honey bees: the nectar is very abundant, and here is another thing to consider: The number of blooms per square foot.
Because it is a tree, the basswood will have an enormous number of blooms when you consider the size of the trunk. To create an overlapping of blooming seasons, consider the height of your blooming material: Canopy of the tree, bushes, garden crops, forbes, creeping vines can be mixed so you can get more blooms per square footage.
I selected these flowers so you get a taste of the variety of positives and negatives for each. There are many other considerations for your choice of blooms. Remember also that each pollinating insect has its favorites and our honeybee is actually NOT a great pollinator. She is the "low man on the totem pole", so to speak, and if you plant *only* for honeybees and your weather keeps the bees in the hives, when they come out, the other pollinators will have picked the blossoms they could have enjoyed, so here again, VARIETY, DIVERSITY is important: Provide for all pollinators, not just the honey bees and you will be richly rewarded by the crops afforded by *all* pollinators.

I collected some black forest pods from an old hedgerow in Saline County, Kansas two summers back. Do you think I can plant them in New Hampshire in the spring? I think they might make good trees for a deer barrier. I have lots of deer in my field and I love watching them, but I don't love how they decimate what I've planted. Some of my gardens are fenced, but I am trying to develop something like a food forest in a lot of places. Does anybody have experience growing black locust in Zone 3 or 4 in New Hampshire or Maine or Vermont? I'd love to know what you've experienced.

Thank you, Cecile. I will consider more before I plant!  I do NOT trust myself to be very vigilant. But my soil is also not at all sandy--but rather rocky and not terribly fertile. I think I'll ask some neighbors what they think.

Hi, I’m hearing a lot about the Invasiveness of black locust but I was just wondering how invasive is it really and is it less invasive in different soils or areas? What are some of your experiences?

Donald Smith wrote:Hi, I’m hearing a lot about the Invasiveness of black locust but I was just wondering how invasive is it really and is it less invasive in different soils or areas? What are some of your experiences?

Here is an interesting article to thinking differently about 'invasives' in general.
https://www.ecolandscaping.org/04/landscape-challenges/invasive-plants/rethinking-black-locust/#:~:text=Black%20locust%20(Robinia%20pseudoacacia)%20is,in%20the%20Northeastern%20Highlands%20ecoregion).
My soil is very sandy, so it offers no resistance to traveling roots from the black locust. Our first water is at 10 ft. and it is all sand between here and there. Not one boulder to alter its travel. It will travel horizontally just below the surface about 6 ft in one season. We get 36"of precipitation/ year. It does quite well even in dry seasons, and bees will visit it but some years, they so not and beeks such as myself do not know why. Perhaps they have a more appealing bloom elsewhere at the same time?
I'd venture to say that in heavy soils black locusts would not compete as well: I was living in Vesper, WI, so in the same zone as here but heavy soil didn't help it. And it was just in the next county.  The soil was heavy and I never saw a wild black locust there, so... Yes, the soil was very influential, You are correct.

It always amazes me how long black locust wood lasts even outdoors in wet conditions. It's impressive what the 4% antifungal compound does for the wood vs other woods without. Maybe the amazing part is less about the locust as it is the power of fungus to break down all carbon-based materials...

Anyway, time to go get some black locust seeds for planting!

I'm a black locust fanatic. I'm also someone who has been conscious of Ukraine as a country since I was in 5th grade when my best friend's dad was an Ukrainian immigrant. And I played a lot of Risk (the conquer the world board game) It originated in Ukraine, and rather realistically the Ukraine territory in the game is the eastern door to Europe. NOW: check out any combat video from the war that shows the common landscape of fields separated by "forest strips": I have seen very little footage of these strips that does not include Black Locust. It's not native, and they love it. They actually have named cultivars for honey production. (I eat the flowers in salad, and I'm NOT DEAD YET!) I am about to build a grape trellis for a Swenson's Red grape in front of my west-facing living-room window and get the grape up above the window. It's easy to split locust. I've heard boat builders like it, and I have built huts of paja reque with locust posts that lasted pretty damn well considering the size of the posts and leaving the sapwood on (not nearly as rot resistant)

Can a black locust tree be killed by girdling?

A lot of uses for Black Locust seems to involve letting it grow, then cutting it down, digging a hole, and burying it. But Nature has already provided it with a taproot! Can we make use of that?

So, if I planted young Black Locusts every 20 feet, let them grow to a fencepost diameter, then girdled them and left them standing dead, I could string wire between them and use the trees just like fenceposts. Mathew Trotter had an idea to use black locust trunks as a retaining wall - the same idea could be tried here.