I like to prune anytime between late winter and when fall temps are very comfortable, but try to avoid when it's getting colder outside. My favorite time to prune is a beautiful day in February.

It doesn't matter what it is for me. The only thing I don't prune are plants that set flowering buds for the next-season...that is if I'm late in remembering to have taken care of business.

Fruit trees should be heavily thinned after they produce and major shaping of them should be done late winter for anyone interested. All the thick, annual-growth you remove are known as: water sprouts.

Dax

Hey Dax,

Even though I had one bad expereience with late winter I'm assuming you haven't had any issues with this time frame?

With the limited expereince on my end I was thinking that the sap is a flowing at that time and thus it was difficult for the plant to heal.

Another consideration for summertime was that the heat keeps the sap thin and therefore just continues to flow.

Logic was pointing to early and late fall but again this is in new for me. I only have a couple plants to the address at this time.

The reading I've done suggests that early spring is the best time for pruning as a general rule, since the pruning wound will heal the fastest as the plant is about to go into its most metabolically active period. While many sources state that trees which are apt to bleed are best pruned in the fall, it seems this is something of a myth; issues with excessive bleeding are mainly aesthetic. IOW, pruning your birch/maple/etc in the spring will cause much bleeding, but this will not harm the tree. The worst time of year for pruning would be late fall/winter, since the wound will remain open for the longest period, affording greater access to pathogens.

As far as I'm aware, pines/spruces and other conifers are no exception to the above. Since your question concerns thinning and heading cuts, timing for bud set is not a concern.

I try to get pruning from March through to September. I doubt that it makes a whole lot of difference when you do it though. In the past, I've pruned Japanese maples in the fall to get around the bleeding thing, only to find that when late winter/spring rolled around, there was still a lot of sap released from the wound. Go figure.

Alex

M. Grove's about got it covered. The sap exudation of "bleeders" when spring-pruned is merely a sign of positive pressure within the tree's plumbing, relative to the outside air pressure. IOWs, a sign of health.

Late winter/early spring before bud swell will serve as the rule for 99% of pruning. Obvious exceptions are things like Dax mentioned-stuff that you're growing for blossoms and which blossom on old wood, and things like taxus hedges, etc. which are pruned during the growing season.

Finally, if it's a snip here, a snip there, like your double leader example, any time is fine.

Oh, then there's oaks. Don't prune those during the growing season if you can at all help it, particularly if oak wilt is in your area. Same would hold true for elms if there were any of them still around.

+oM

+om

define the end of the growing season for oaks ....

any sooner than leaf fall???

i gotta teach some more oaks a lesson in who is in charge of this garden... and then have a big fire to appease the pruning gods..

ken

Took a pruning class from an ISA arborist/horticulturist who said the same thing that +oM said - don't worry about the 'bleeding', for the same reason +oM cited. In their world (he was also a certified aesthetic pruner) the only reason that they didn't like the bleeding is if it stained the trunks, more of an issue with deciduous trees such as Japanese maples.

Sara

All, thanks for the info. I just wasn't sure if the pines and spruces where considered bleeders. I might try pruning in September to see what kind of results I get.

True, species that are subject to sap loss will not harm the tree in all cases per say but its known that there is more risk associated with pruning bleeder species in spring vs. summer.

You basically run the possibility of prolonged bleeding with can cause damage to the healthy bark below the cut and you also prolong the callusing of the wound, which can open the door for disease. Its the same reason you don't prune Oak during the growing season.

At the end of the day I bet your more likely to get in a car accident than having issues with going against the grain above!

years ago when I first went to work for a nursery I asked the owner what was the best time to prune. He said, "Whenever you have the pruners in your hand".
If you only prune at the optimum time, it will probably not get done. Maybe some years, but not all.
Take a look at this bleeder. It's an Acer cappillipes that I cut down at the beginning of May.
Mike