“OFF again ON again” Crataegus

[Random Usr]

I've been growing a Crataegus yamadori for about 4 years now. The first year I had neither blumes nor haws. As the years progress it's been getting more of both. Last year is was awash with blumes and haws! Magnificent! This year I got only a few blumes and only 4 haws. Is this normal for Crataegus or is it time for some maintenance? I have never re-potted it …. even once. Maybe it is time?

 

[Random Usr]

That's what I thought.

 

[0soyoung]

... crickets ...

I know that there must be blooms to have berries. The blooms must be pollinated for haws to develop, so the things that affect pollination = a variable.

I have lots of azaleas and rhododendrons in pots and in the landscape. I note that they bloom heavily some years and not so much in others. I am unable to account for why and have yet to find out why.

Flowers are modified apical meristems (growing tips at the end of branches). Once things have happened to allow the process to proceed (reaching 'adulthood') certain other variables drive the metamorphosis into flowers. I do know that the auxin produced by the set leaves immediately below the bud are integral in the process in azaleas and rhodies. Remove these leaves and flowers will not develop; equivalently, prune too late. But leave all this and flowers don't necessarily develop - dunno why; would love to understand what to do to get more flowers. Some factors of like-kind (whatever they are) must affect all angiosperm flowering.

growing a Crataegus yamadori for about 4 years now ... is it time for some maintenance? I have never re-potted it …. even once. Maybe it is time?

I'd say probably so, but don't know that there is a relationship to flowering. On the other hand, if it is still growing robustly, maybe not.

 

[Alain]

... crickets ...

I know that there must be blooms to have berries. The blooms must be pollinated for haws to develop, so the things that affect pollination = a variable.

I have lots of azaleas and rhododendrons in pots and in the landscape. I note that they bloom heavily some years and not so much in others. I am unable to account for why and have yet to find out why.

Flowers are modified apical meristems (growing tips at the end of branches). Once things have happened to allow the process to proceed (reaching 'adulthood') certain other variables drive the metamorphosis into flowers. I do know that the auxin produced by the set leaves immediately below the bud are integral in the process in azaleas and rhodies. Remove these leaves and flowers will not develop; equivalently, prune too late. But leave all this and flowers don't necessarily develop - dunno why; would love to understand what to do to get more flowers. Some factors of like-kind (whatever they are) must affect all angiosperm flowering.

I'd say probably so, but don't know that there is a relationship to flowering. On the other hand, if it is still growing robustly, maybe not.

Oops, didn't know that, I hope I didn't screw-up the pruning of the landscaping azalea of my wife 'Pretty little liar' bedding of flowers in the front yard

 

[Random Usr]

... crickets ...

I know that there must be blooms to have berries. The blooms must be pollinated for haws to develop, so the things that affect pollination = a variable.

I have lots of azaleas and rhododendrons in pots and in the landscape. I note that they bloom heavily some years and not so much in others. I am unable to account for why and have yet to find out why.

Flowers are modified apical meristems (growing tips at the end of branches). Once things have happened to allow the process to proceed (reaching 'adulthood') certain other variables drive the metamorphosis into flowers. I do know that the auxin produced by the set leaves immediately below the bud are integral in the process in azaleas and rhodies. Remove these leaves and flowers will not develop; equivalently, prune too late. But leave all this and flowers don't necessarily develop - dunno why; would love to understand what to do to get more flowers. Some factors of like-kind (whatever they are) must affect all angiosperm flowering.

I'd say probably so, but don't know that there is a relationship to flowering. On the other hand, if it is still growing robustly, maybe not.

Sounds logical to me.

 

[0soyoung]

Oops, didn't know that, I hope I didn't screw-up the pruning of the landscaping azalea of my wife 'Pretty little liar' bedding of flowers in the front yard

Possibly and maybe not - timing matters a lot. Flower bud set occurs sometime after the summer solstice. Look closely at the terminal bud. Flower buds are distinctly fatter than leaf buds. So just don't prune until after you can see the terminal is opening into green leaves if you are in doubt.

IIRC, hawthorns are similar to cherries in that flowers are primarily at the tips of 'fruiting spurs' or new(-ish) short lateral branches. Again, the shape of flower buds is somewhat fatter than a leaf bud, but it can be very difficult to tell in many species. I still do poorly identifying Fuji cherry flower buds from leaf buds in the spring (this could well be a personal problem ).

 

[ABCarve]

I've been growing a Crataegus yamadori for about 4 years now. The first year I had neither blumes nor haws. As the years progress it's been getting more of both. Last year is was awash with blumes and haws! Magnificent! This year I got only a few blumes and only 4 haws. Is this normal for Crataegus or is it time for some maintenance? I have never re-potted it …. even once. Maybe it is time?

You may be pruning off next years buds. Keep track of which twigs flower. They will not extend beyond what has flowered and will start forming next years buds which will emerge to flowering twigs. At least this is how mine works???

 

[Leo in N E Illinois]

Something as simple as one day of letting the tree get dry to the wilt point if during the critical period of flower bud formation can kill of flower buds, similarly late frosts, pruning and other activities. If your vegetative growth is good, repotting or not repotting won't affect the blooming. Cause of not flowering is not the roots, if vegetative growth is good.

By the same token, if vegetative growth is poor, check whether you need to repot. Don't repot more often than necessary, but do repot when it is time to work roots, refresh media that no longer is draining, or to shift to more appropriate pot. Many people repot more often than need and slow development as a result. For show ready mature trees, repotting is used deliberately to slow growth.