North American Fruit Explorers mailing list at ibiblio

[Douglas Woodard <dwoodard@becon.org>]

I think that much depends on *what* you are pruning and *why* and 
*where* and *when*.

I recall British discussions of pruning apricots. With them in Britain 
apparently the big problem is a bacterial disease called "dieback" which 
can be deadly. The recommendation as I recall it was to prune in early 
June (?) at the time of fastest growth when the tree would be least 
liable to infection and wound healing quickest. Apparently this was 
found to give satisfactory results but pruning at other times had been 
found to be dangerous. I suspect that other species of Prunus in other 
places may be subject to similar considerations.

In Niagara Peninsula orchards the custom is to prune peaches when the 
trees are in blossom, perhaps partly for quick healing but probably 
mostly so one can see what the effect of winter has been on the fruit 
buds, and whether the need is to reduce or conserve the crop.

Regarding promoting growth versus dwarfing in apples:

If you prune during the dormant season (but in cold areas it's best to 
prune when the risk of extreme cold is past, at least after the first 
half of February) then the stored food from the roots is sent up into 
whatever wood remains on top to promote growth. Whether this is good or 
bad depends on the situation. Is the tree a weak-growing or a vigourous 
cultivar? is it bigger than you want or do you want it to grow? what is 
the soil? water supply? light exposure? Are you trying to dwarf the tree?

If the aim is dwarfing then one wants to wait until whatever sugar was 
stored in the roots has been brought up, and maybe till after the spring 
flush of growth has passed.

Adjusting crop load or exposing fruit to light may suggest different 
timing.

If cold-hardiness is in doubt whether due to cultivar or location, then 
I'd say don't prune after mid-July or in extreme cases the beginning of 
July.

If you are pruning to shape a vigourous cultivar which hasn't yet borne 
its first fruit and is known to be late in coming into bearing (Northern 
Spy is the classic example) then you want to avoid dormant pruning and 
to prune as little as possible, guiding growth by techniques like 
pinching buds as much as you can. With a young Spy tree on seedling 
stock you can delay its fruiting till the 20th year by careless dormant 
pruning.

I suggest that you think about the factors that are operating in your 
case, put them together, and be wary of simplistic old sayings.

Doug Woodard
St. Catharines, Ontario, Canada



Jwlehman@aol.com wrote:
> In a message dated 8/28/2010 9:47:08 AM Eastern Daylight Time, 
> billg@inebraska.com writes:
>
> > OK, but in that case, wouldn't I be better off pruning now, rather 
> > than waiting for dormant pruning? After all, in either case, the wound 
> > won't be healed by spring. But it might be a LITTLE further along if I 
> > prune now.
>
>
> Hello Bill,
>
> I submit there are fungal spores in the air now that will not be there 
> in say Feb. Pruning now before spring active growth begins simply leaves 
> the wound open and exposed longer.
>
> But if you will be tight for time next spring now is better than not 
> pruning at all.
>
> I heard one man say once there are only 52 days a year that you can't 
> prune apples, every Sunday. But I've pruned many trees on Sundays and 
> lightening hasn't struck me yet.
>
> Jerry