I bought this nursery stock Mugo Pine late last fall with the intention of repotting this spring. I believe it is grafted onto black pine roots. After doing some research I decided to wait until late summer to do it. I am in S.W. Pa, zone 6a.
I am seeking advice as to what signs to look for in the tree’s growth that will tell me it is a good time to repot. Also, can I do any structural design at this time or should I wait and let the tree recover? This is my first post in the forum so any suggestions are appreciated.
As far as repotting, I wouldn’t suggest doing a summer/late summer repot. Repot in late winter/early spring. Reason being, pines strength is in the roots. They have a very coarse root system and repotting in the summer can challenge the trees ability to take in water.
That being said, you can style it this year after the new growth hardens off if you’d like and save the repot for early next year. Also what makes you think it is grafted onto JBP?
Thanks for the advice. I had read Mugos can be repotted in either late winter/early spring or late summer/early fall. There seems to be some contention on the subject. I wanted to get an idea as to what the root base looked like before I started styling.
As far as the grafting, I read that many pines are grafted onto JBP because the roots are more water tolerant.
Don’t believe everything you read on the internet.
– Abraham Lincoln
0 stars, would not recommend Zone 8b/9a, PNW, near Mirai
I read the same about Mugos on the internet and tried an end of August repot on one a few years ago (before Mirai Live).
~40% root mass reduction from nursery can, into 60:40 pumice:nursery soil, screened
The tree survived, but BARELY pushed any new needles in the spring. The next year’s growth was a little better, but really took 3 years to get back to full vigor.
Finally got to style it last year (4 years) and repotted again into a new container in February this year. Candles are still extending right now, but I’m not seeing much loss of vigor due to repot. ~65% root mass reduction (lots of matted roots) into 1:1:1 akadama:pumice:lava. Much smaller pot, high confidence in the remaining roots
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Early spring repots have more room for drastic work. On a first repot from a nursery can, you never know what you’re going to run into. Better to have more flexibility and a higher chance of success.
You can repot in late summer, just like you can grow a tree indoors. Having a tree survive is not the same as having it thrive, though.
Do you guys think it would be ok do a light pruning to establish initial style (after the new growth gardens off) this year? I did pinch off the largest candles to promote bifurcation this spring.
Thanks for your advice. Very happy to be able to participate in the Mirai forum.
It looks like you got a strong spring push of growth and I would feel comfortable to style the tree this year and set the structure once it hardens off. Just remember that you are going to reduce the root mass quiet heavily in spring so don’t take off too much foliage as it will help regenerate the roots post repot.
My first-hand experience, zone 8a/8b with mugo repots:
Late summer repot, 50% root ball reduction, in colander with seramis (baked clay): massive new root growth before dormancy. New fleshy roots were trying to escape the colander within a month of repot. Very good compact growth this spring, short candles and needles. This is a mugo I had put in the ground during my move four years ago, and it didn’t exactly thrive in the ground for three years so I decided to lift it up. It will go through initial styling this year.
I bought a small lot of young mugos for pocket change ($3 each) last winter through the club, so I decided to perform an experiment with them.
The first one had a late winter/early spring repot, 50% root ball reduction and bare-rooted, in colander with akadama/lava/pumice: no new root growth visible yet, long ramified candles (some candles have smaller candles growing off them).
I have two additional mugo pines to repot this year. One will be repotted in June and one will be repotted in August. They will otherwise be treated the same way as the spring one: 50% root ball reduction, bare-rooting, colander with akadama/lava/pumice.
Thank you. I appreciate everyone’s advice. Maybe I’ll get another Mugo and do my own experiment. Last year, (spring 2019) a friend of mine who is a landscaper gave me a mugo she rescued. I immediately repotted AND styled it and it promptly died so I learned not to do more than one procedure at a time on them. Wish I would have been part of the forum then.
