Japanese Black Pine

[terryb]

How/ when to remove pine shoots depends what stage your pine is up to.

Hi shibui,

Thanks for your reply. Sorry I was unclear. I meant removing the flowers. The post by @Lane above indicated that removing the flowers gets the tree growing again. This tree hasn't really moved, whereas the candles on the small JBP I got from you this year are happily elongating.

I guess your tree is in development phase where you want more thickness and growth. It does not really matter if it is flowering. If you are still growing and developing the tree just leave it all there - with or without flowers for up to 2 years but prune branches back before the old needles start to drop so you can get back buds to grow new shoots.

I've only been growing JBP for a year, so am still learning the ins and outs. I have kept this one alive and growing for a year so I'm happy they'll grow for me and I now need to learn the developmental stuff.

When you say "prune the branches back" are you referring to just cutting the candles or even going back beyond the candle to stimulate needle and adventitious buds? For instance, you can see a small shoot quite low down in the first picture I posted. I'm assuming I don't need to cut way back down to there? On the other hand, there is a strong whorl above that which has thickened up so maybe I do?

If your tree is in the ramification phase - building up branch pads and density cut the shoots in December to get lots of new buds at the base of each shoot. Early pruning tends to give long new shoots, later (December) pruning tends to give much shorter shoots with smaller needles that give better branch density.

Cheers, have filed this away for later in the journey.

[shibui]

I know Lane said that removing flowers makes the tree grow but immediately after Alpine said his trees that were flowering had grown more than the ones without flowers. Why do you focus on one but not the other?
In my experience flowers do not slow growth of JBP so I would not bother removing them. If you are determined to do so, just rub them off with your fingers. They should drop off reasonably easily.

You have 2 options for pruning JBP.
1. Decandling - cut the new shoot just above the older part. New buds grow in a ring around the base of the cut candle. This is usually used when you need to limit growth and encourage ramification after the tree has achieved desired size and for maintenance after that.
2. Hard pruning - cut shoots further back into older needles. New buds will grow from the old needles. This method gives ramification but, more importantly, gets new shoots with new needles growing lower on the tree. It is important to maintain some healthy young needles in places where you will want branches, etc later. People who let the pine grow freely for more than 3 years end up with long, bare trunks and branches with little hope of getting adventitious buds to grow branches. You can prune anywhere there are healthy needles and expect to get new buds grow.

Pines are very prone to swelling where there are whorls of shoots. Try to remove most shoots from a whorl early, well before the area starts to thicken. If the thickening is not too pronounced it may disappear as the tree thickens.

[Keep Calm and Ramify]

Terryb,
I have had plenty of flowers form on my JBP over the years (sometimes it looks likes it's "smoking" when its watered from overhead or brushed against from the pollen release) I have to agree that the flowers seem to cause no ill effect in the growth or health of the tree. They are usually short lived once in bloom & you could remove them at any stage.
Enjoy in the development of your tree.

[terryb]

Thanks shibui and KC&R.

Oops, missed that Alpine post. Entirely my fault.

[terryb]

I'd like to update this thread with some more observations.

Following my post last year, I decided not to worry about the pollen cones and just let the tree do its thing, focussing on thickening the trunk. The tree grew strongly (apologies for the busy background)

20190622_JBP1.jpg

In June, the tree was cutback and some needles plucked to get some more light into the small back buds lower on the trunk and it went back on the shelf. Here is the tree in early October with most of the pollen cones on what I consider the strongest shoots. The less vigorous shoots closer to the trunk had fewer cones.

20191005_JBP.jpg

What I have noticed is that the pollen cones do initially slow the extension of the shoots (reproduction trumps vegetative growth) but I think this is a good thing and here is why. The stronger the shoot, the more pollen cones it produced. The more cones, the longer it took for the shoot to elongate. Thus it appears that the energy is redistributed and the weakest shoots (the small back-buds) began to grow, while the growth in any shoot with cones was suppressed. The shoots from the back-buds are now about 7cm long.

20191005_backbuds.jpg

20191005_backbuds_close.jpg

The rest of the shoots have now begun to elongate, from weakest to strongest and I noticed in the last few days that the strongest shoot on the leader is just waking up. Once that gets going I expect that growth on the weaker shoots will slow considerably. Will keep watching and see what happens.

20191005_branch.jpg

20191005_leader.jpg

[Ryceman3]

Will be interested to see what happens with this terryb.
I have cones on several of my JBP (female flowers) but I have never had male flowers like the ones you posted... not sure what that says about me or my pines, just an observation! Maybe I should leave a few of these on and see how that affects candle/shoot development...

[terryb]

Are you referring to just your progeny from "The Pine Project"? A couple of the JBP I got from you did get a single female cone each on them this year and I also had a couple of female cones on the strongest shoots of my other two JBP but I removed all of them. I figure these need to be supported by the tree for long time (see Shibui's post above) and my goal is trunk thickening.

[Ryceman3]

Are you referring to just your progeny from "The Pine Project"?

Not really, yes for them but also others ... I have never had male flowers occur on my pines - having said that I have only had pines for the last 3 years or so and they are all quite young so that isn't a "blow your mind" statement.