Washington Hawthorne--tough to get flowering?

[Corrado]

Assuming the trunks are thick like 2 inches and aged at least 15-20 years old, and using plenty of high phosphorus fertilizer, what else can be done to get them flowering. I had one for over 20 years in my care .HEalthy vigorus growth every spring.Root pruned every 3 years . I tried letting some growth go untouched for 2 years and others pinched back to 2 buds on every twig. It never flowered . I sold it off n disgust. Now I have 2 more with thick heavy trunks probably over 15 years old. ID like to get them to flower. They are the bottom 2 pics

 

[camikins]

Hey - similar challenges here. But am now following Graham Potter's seasonal pruning advice to see if it helps. Have you seen his instructions? https://www.kaizenbonsai.com/bonsai-tree-care-information/getting-bonsai-hawthorns-to-flower

 

[Mike Hennigan]

I could be wrong, but i’m pretty sure that hawthorns will only flower on the previous years new growth. So if you’re pruning them back heavily each spring before bud break this may be part of the issue.

 

[Leo in N E Illinois]

I read the Graham Potter article, it makes sense. It was a shame you got rid of the older hawthorn, likely it would have started blooming eventually. Once you are past 20 years, it should bloom.

Fertilizer. The practice of using high phosphorus fertilizer towards autumn is archaic, a practice developed in areas of heavy autumn smog, where the acid rain provided all the nitrogen the fruit and vegetables needed. It was developed in London, in the 1880's at Kew. Books have endlessly repeated it without question.

Excess phosphorus can disrupt normal growth. It is possible excess phosphorus is causing your lack of bloom. Read information from more current research, like the information coming out of Michigan State University, Horticultural Extension Services. A balanced fertilizer is actually something like 12-0.9-11 if nitrogen is as nitrate. If nitrogen is a blend of ammonia, nitrate and urea, the ideal formula is 12-0.9-4, a good fertilizer will supplement calcium, magnesium, & sulfur.

The ratio of nutrient uptake does not change with the seasons, only the quantity required changes. Light feeding in autumn, heavier feeding in late spring & summer.

Do read Potter's article, and throw out your high phosphorus fertilizer.

 

[Brian Van Fleet]

My little-hip hawthorn was in bloom when I chopped it to a stump and collected it 19 years ago. It has not bloomed since. I suspect it has a lot to do with pruning during the current growing season, because the one I collected and @Dav4 now owns blooms when he lets it run wild.

 

[Dav4]

My little-hip hawthorn was in bloom when I chopped it to a stump and collected it 19 years ago. It has not bloomed since. I suspect it has a lot to do with pruning during the current growing season, because the one I collected and @Dav4 now owns blooms when he lets it run wild.

Yup, and I cut back the sacrifice branch lightly during last year's growing season and poof... no blooms this spring after blooms two years in a row.