How late can you do a hard cut back?

[Maiden69]

For the folks growing stock from nursery to pre-bonsai material... how late do you hard prune trees? Last year was a waste as far as taking care of my trees. Between the time at the apartment to moving into the new home the trees just sat in unfavorable conditions, ie. too much shade, substandard watering, etc. I was able to move them into a better location early-mid spring and they are growing strong now. With that said they are over grown and need a haircut. How late can I do this? Being in central TX I have around 3 more months of decent growth before it starts to cool down in November, hard frost usually comes in around January with an occasional very cold day (or week) in December.

The species I am inquiring about are tridents, JM, zelkova, Chinese elm (regular, yatsubusa and seiju), pomegranates, prunus (incisa, mexicana, and yedoensis), cork oak, and a few misc. JBP I'm not worried as I can find a lot of info in Jonas website and here since he touches topics from seedlings to field grown, plus the few threads on the six year contest here that has a lot of good detailed information. Most of the trees are in the 2-3 year seedlings category.

Also, for those doing air-layers, how late would you start one? On elm, JM and tridents?

Lots of questions, last year set me back a lot. This new year will be great, as I will finally have my grow out area complete.

 

[penumbra]

In your zone I would think almost anything deciduous could take a hard cut back now. I am zone 6b and my basic cut off is now, the first week of July. But this is a general time and there are some I cut back earlier and some I would not hesitate to cut back later. I have done almost all of my hard cut backs, but I will likely still be doing some within the next couple of weeks.

Most of the trees are in the 2-3 year seedlings category.

These will respond rapidly.

 

[rockm]

I just did my second “haircut” on my hair oks and maples this week. Down that way you could probably get away with what you’re planning now but wouldn’t wait much longer.

 

[Maiden69]

I guess I will be busy this weekend. Thanks.

 

[Shibui]

I can prune hard well into Autumn (Fall) on most deciduous. I once pruned JM hard right at the end of Autumn. The trees grew new shoots and then did not drop leaves through winter. No long term damage as they returned to normal cycle the following year. Results may vary depending on actual climate/ remaining growing season and winter temps.
Cork oak is the only species listed that I'd be concerned about.
It's only just past Summer solstice so I'd be pretty confident hard prune now would be OK for most places in Northern hemisphere.

 

[leatherback]

I keep midsummersday, so June 21st as a rough point to think about whether I do still want to make big cuts. You do not have Linden, but that is a species I do not prune after the longest day as it will often not respond. Zelkova, Elm and maples however I prune all summer long, they will most often resprout.

As @Shibui indicates, be wary of pruning those late in the year mostly because of slower dormancy. I try to avoid pruning them after start of september, as not to get a new flush that does not harden before winter arrives, sometimes already in first weeks of October.

Prunus is sensitive to infections and I would try to avoid big cuts on them after mid-summer, so the tree has time to properly compartmentalize the cutsite.