Maple pruning

OK, so I've heard since I was a kid that you can't prune maples in spring 'when the sap is running'. So when exactly is that? I've got lots of maples leafing out now and it seems like the clearest time to see where pruning is needed. Can I go for it?

Make one pruning cut, and see for yourself what you think.

Shouldn't is probably more properly the term - not can't.

Summer pruning right before another flush of new growth is good. Pruning in fall after leaf drop is when I have also successfully worked on this genus.

Bummer. I was hoping for different answer, but thanks anyway. Supposed to be a glorious day here today, so I guess I'll have to pull weeds instead.

After the ice melts from the deck, I'm going out to whack a couple branches from three different maples - and take pictures to report back the results.

I think it will be informative, so that it's not just something you read about or hear about - you can see it RIGHT HERE.

I'd encourage others to report their experiences.

OK - at 38ºF it is still pretty brittle to go outside to make a point. I did want to see if temperature had any significant effect on this issue.

It does NOT.

Here is a young Sugar Maple seedling (Acer saccharum) that sprouted at the Valley. I made some pruning cuts last summer to subordinate competing leaders and reduce extensions on lower branches that should eventually be removed. These exhibited no "bleeding" (excess sap drainage) when these cuts were made.

I made one cut to remove the lowest branch on the trunk. The response was immediate - see for yourself.

The length of time between the picture of making the cut, to the last image with drips down the trunk: two minutes.

Pretty impressive show-and-tell. Thanks.
So why does it harm the tree to have some sap leaking out?
Does it dessicate the tree? Make the tree prone to infection?

Harm is such a judgmental term.

Without specific botanical or arboricultural reference, I would suggest that pruning now and purposefully losing sap running down the trunk is a waste of perfectly good energy - that should be helping the tree leaf out and grow.

So I would say no to definitively causing harm, dessication, or infection - but that the knowledge that it isn't the best time to prune in spring should reign.

Unless you're just a big Blue Devil...

Lots of Blue licking their wounds this year ...
And green and red and ...

Dang Ducks - they were my predicted champs.

Now it's "anyone but NC..."

Heading for Houston next weekend. Always a blast!

We'll want to see "Trees of the Final Four".

I'll see what I can come up with.
Our usual final 4 activities always include visiting the local arboreta/botanical gardens. But this year we have to deal with the complication of a new member of the family making her debut serendipitously in Houston in the next day or two. So baby viewing will definitely impact our free time!

Now - that's planning ahead to have prospective maternity at site and time of Final 4.

Worthy of a GameDay episode...

I have many japanese maples and always prune them in late winter when I can see there branch structure. Some times there is sap coming out and other times not so much. Depends on how close to spring it is. This year I trimmed them 6 weeks ago and did not have much if any sap running.

On some sugar maples bordering my property I prune overhanging branches 3 weeks ago. Those cuts did have sap running for a few days.