Hawthorn won't flower

[Joe Dupre']

Try a phosphorous heavy fertilizer. Plants want to flower and fruit if they think their life is in danger so maybe crack your knuckles at it and make a few threats (or clip back the vegetative growth). My dad swears by chicken manure for flowering trees (it has nitrogen but a lot of phosphorous and potassium too), maybe try some well aged stuff so it doesn’t burn. If that and time doesn’t do it you might very well have a happy boy hawthorn. Are parsley hawthorn native to your area? You’ve seen flowers on the wild ones?

Yes, I've seen flowers on the native ones. I didn't find this tree in the late spring when it might have been flowering. I dug it in late winter.

 

[Sansokuu]

Yes, I've seen flowers on the native ones. I didn't find this tree in the late spring when it might have been flowering. I dug it in late winter.

Can you go back to the spot in late spring? Were there others in that location, to check which ones are flowering? If all are flowering then continue waiting, if some aren’t, could be a male as others suggested. *edit* Though internet sources say this species is a hermaphrodite so it is both male and female.. it also likes lots of moisture and part sun.

 

[Crazy Diamond]

Can you go back to the spot in late spring? Were there others in that location, to check which ones are flowering? If all are flowering then continue waiting, if some aren’t, could be a male as others suggested. *edit* Though internet sources say this species is a hermaphrodite so it is both male and female.. it also likes lots of moisture and part sun.

Most of Crataegus have hermaphrodite flowers, people have collected them knowing they flower and after collection years and years of nothing so it must be something to to with rootball reduction from the field, living in a shallow pot, or something else related with bonsai practice

 

[Sansokuu]

How often do you repot? According to this source it doesn’t like its roots messed with, and suggests repotting every 3-5 years.. https://www.kaizenbonsai.com/bonsai-tree-care-information/getting-bonsai-hawthorns-to-flower

“Often when we collect old hawthorn they will flower very well but this declines over a few seasons. This happens because the trees situation will have improved and it gradually reverts to a 'juvenile' state of expansion growth. Over time energy is diverted away from mature fruiting growth towards expansion growth and flowering quickly declines.

The following technique should only be applied to relatively mature trees with a fair level of secondary branching, not raw material in need of primary branch growth etc'. The hawthorn resents root disturbance and will only normally need to be re-potted every 3-5 years. Fertilise the tree very well from February (late winter) until late autumn with a balanced fertiliser.

1. In spring allow shoots to extend until the growth at the base 'just' begins to harden off, then cut back by 3/4. Prune harder at the top of the tree and less lower down. Do not leave this too late or you will not see the strong second break of growth that is very important.
2. Leave the second break of growth in tact without pruning unless you see a very strong long shoot. This second break will be more balanced and even than the first. Constantly remove budding and shoots from the trunk area.
3. In late January prune the growth back to create your desired branch profile but leaving a little of the previous years development to increase ramification. Year on year prune one or two twigs back harder to prevent knuckles forming. Always prune close to a bud and seal cuts.

“In the initial years of using this technique your tree is going to look a little out of shape for much of the time, as the tree matures and ramification increases the situation will improve greatly.
The technique relies upon controlling apical dominance and will evenly distribute energy throughout the tree whilst allowing it to still fuel strong growth and maintain vigour. The whole crux of the idea is that the secondary growth will mature over the autumn and early winter. Strong apical buds will form at the end of the shoots. In late winter these are removed and as a result the tree will fuel development of all growing points rather than just the branch tips. In the first season you will not see flowering but in the second year it should begin and will subsequently increase. A strong healthy tree will easily make two breaks of growth in a season as long as you prune the first break fairly quickly.”

 

[Cajunrider]

Getting Bonsai Hawthorns to flower

THE MOON FLOWER Crataegus monogyna is a small tree native to the U.K, and parts of Europe, that has come to be known by many names. Hawthorn, May tree, quickthorn, whitethorn, haegthorn, hedgethorn, bread-and-cheese tree and, most evocative of all Moon flower. The tree is steeped in folklore...

www.kaizenbonsai.com

 

[Joe Dupre']

Getting Bonsai Hawthorns to flower

THE MOON FLOWER Crataegus monogyna is a small tree native to the U.K, and parts of Europe, that has come to be known by many names. Hawthorn, May tree, quickthorn, whitethorn, haegthorn, hedgethorn, bread-and-cheese tree and, most evocative of all Moon flower. The tree is steeped in folklore...

www.kaizenbonsai.com

CR, I saw this a couple of years ago and have been trying it for the most part. Thanks.