Sunday, December 14, 2014

My Baker's Dozen Apple and Pear Pruning Tips

As it approaches time to begin pruning your apple or pear orchard, here is "My Baker's Dozen Apple and Pear Dormant Pruning Tips."

1. Don't prune before January 1
Try to finish pruning before bud-break (although until bloom is allowed); don't prune when it is very warm or predicted to get very cold.

2.  It's all about farming the sunlight
Apple and pear wood needs to receive adequate sunlight (50% is commonly cited, whatever that means?) to form quality fruit buds and produce top-quality fruit. Just remember, shade is your enemy. Although not easy to accomplish, fruit buds in the bottom of the tree should get nearly as much light as buds in the top of the tree. (This is why very narrow canopies, as in a fruiting wall, are in vogue.)

3. Leave the hand-pruners in the shed
Larger apple and pear wood (4-years old and older) needs to be removed during dormant pruning using a saw and/or high-quality lopper. (I like Hickock or these -- and only these -- Corona loppers.) A small chain saw and pole chain saw should be in every pruners arsenal when dealing with semi-dwarf trees. (And sometimes dwarfs that have gotten out-of-hand!)

4. Avoid heading cuts like the plague
Use thinning cuts to simplify lateral and/or scaffold branches; more simple lateral and/or scaffold branches are preferable to fewer complex branches; thinning cuts typically allow sunlight to better penetrate the apple or pear tree canopy.

5. Limit tree height to no more than 90% of row spacing
If row spacing is 12 feet tree height should be limited to 10 feet. (Yea I know my math here is suspect, but round to the nearest foot less than 90% after doing the calculation -- who can relate to 10.8 feet?, and 11 feet is too tall!) "Crop-and-flop" the central-leader, i.e., don't cut the leader if at all possible to limit tree height until it has "cropped and flopped," then cut to a weaker side-shoot to limit height.

6. Use diameter-based pruning, particularly on the central-leader
If a branch is more than 1/3 to 1/2 the diameter of the branch (or central-leader) from which it originates, cut it out using a thinning cut; I've been leaning to using the 1/3 diameter cut-off more and more...

7. Forks belong on your dinner table, not in your orchard!
If you can picture it, it is corollary to 6. above.

8. Use the 1-2-3 rule, particularly in dwarf, spindle-type orchards
After pruning, you should have a balance of 1-year-old, 2-year-old, and 3-year-old wood; 2- and 3-year-old wood is fruiting, 1-year-old wood is left to become 2- and eventually 3-year-old wood; 1-year-old wood is preferably pencil-diameter and 12-18 inches long and left UN-HEADED!!!

9. Cut-back (or remove) wood that droops below 45 degrees from horizontal
Pendant wood is weak and will produce smaller, poor-quality fruit. I know, I know, this would arguably be a heading cut, but if you are ever going to use a heading cut, by all means, use it into weak wood! Of course, also cut out (using a thinning cut!) vigorous, upright shoots and water-sprouts.

10. Remove one to several of the larger branches
Except on central-leader trees where a permanent lower-scaffold branch structure has been developed, in general it is desirable remove the 1, or 2 (or 3) biggest branches (using diameter-based pruning as described above) originating on the leader, particularly in the top of the tree.

11. Favor a palmette-shape tree top going down the row
If your rows are planted in a North-South orientation (as they should be!), favor keeping branches in the row vs. into the row -- this helps prevent shading and creates a palmette-shape top of the tree; I use this when making decisions (based on diameter-based pruning) on which bigger (older) branches are being removed (using a thinning cut!) in the top of the tree

12. Experienced pruners, read this

13. Beginning pruners and homeowner, read this

Did I miss something? Feel free to leave a comment...


Friday, May 30, 2014

The spring of our discontent?

It's been a prolonged spring in Massachusetts. Preceded by a long and very cold (near record) winter. Following a hot summer in 2013 with a very large apple crop. Now we're paying the price? I have been asked about the tree fruit crop situation here in Massachusetts. I just want to say it's all over the place, so let me try to explain.

For starters, the 2013 apple crop was a large one, and it was a hot summer. Apples reached the tipping point after several large crop years -- typically biennial apples such as Cameo, Golden Delicious, Goldrush, Honeycrisp and others which bore a large (too large!) crop of fruit in 2013 have a lot of "blanks" (no flower parts, see below) in 2014. And, by-and-large, bloom on other varieties such as McIntosh (our primary variety grown) is variable, but we will have fruit. Macoun looks good, while Cortland bloom was lacking at best? As apple bloom progressed, quite a few flower spurs with malformed buds and/or single blooms were observed -- what the heck? Theories abound, ranging from incomplete/late flower bud development last year, winter injury (although it did not get absolutely cold enough to suspect damage?), an April cold snap when the buds were pushing (although according to critical temperatures, damage should not have occurred)? Quite a few Honeycrisp flowers at the UMass Orchard in Belchertown had just one flower (see below). Apple bloom just did not look good. (Queasy feeling begins.) Although I was pessimistic (as usual, cup is half-empty) I kept thinking it usually turns out better than I expect, and indeed now that we are seeing fruit set (finally) it looks like there is actually potential for a good apple crop here, other than the exceptions already noted. Somewhat interesting, considering how wicked cold the winter was, is the fact we got through bloom with no real frost/freeze threat (except back in early April).
Honeycrisp "blank" flower, 14-May, 2014 at UMass Orchard
Honeycrisp single flower, 14-May, 2014 at UMass Orchard
Let's move on to stone fruit -- peach and cherry. They have not fared so well. A good sign of trouble was mid-winter cold approaching or exceeding -10 F. Damage to flower buds of peach is highly site- and variety-dependent, but begins at -10 F. This spring, it looks like the potential peach crop ranges from no (zero) crop, to maybe what will be a good crop with modest hand-thinning. Some locations/varieties will need very little, if any, hand thinning to produce a decent peach crop. I estimate flower bud damage to range from 100% (again, depending on variety and site) to 50% (maybe lower). I don't think any peach orchard escaped unscathed. Not since 2004 have we lost a peach crop (or partial crop) to mid-winter cold.
Good peach flower bud (top) and bad (winter injured) peach flower bud (bottom)
at UMass Orchard, 5/14/14
Sweet cherry, well, I was pretty pessimistic, but set looks better than I expected. It is, however, variety-dependent. Clearly there was some damage, but I don't have it well-documented. Past history suggests you will start to see sweet cherry bud damage at about the same mid-winter cold temperatures as you see with peach. I want to share one observation, which is confounding but probably fully explainable -- my perception is that you see better bud survival on the weaker wood of peach and cherry, vs. the kind of wood that we would like to think produces the best fruit, i.e., those nice long, pencil-diameter size shoots. I suspect the weaker wood/buds is actually more hardy, having less nitrogen and hardening-off sooner in the late fall to early winter. It might not wake up quite as readily during mid-winter warm-ups too. Kind of frustrating when we attempt to grow "good wood."
Rainier sweet cherry fruit set at UMass Orchard,  5/27/14
Finally, seeing some wood/shoot damage to stone fruit (peach and plum) from presumably the mid-winter cold. It was dry last fall, so going into the winter these trees might have been pre-disposed to damage with a harsh winter.
Winter-damage peach tree in eastern Massachusetts, 29-May, 2014
That is the current situation as I see it -- I will give apples a B+ and stone fruit a C- at this time, however, am not averse to giving them extra credit and improve their grade as the growing season progresses. I constantly have to remind myself as the season goes along that more-and-more fruit suddenly "appears" (don't dismiss chemical thinning of apples!) and that years with a "short crop" are often the most profitable. (As long as you have some fruit!)

Saturday, January 4, 2014

Near record cold...

Daily (morning) lows (degrees F.) for 01/04/14 in Massachusetts. Peach (and other stone fruit) bud damage will occur at -10 F., depending on variety and preceding weather (which has been cold). There was likely some bud damage to less hardy peach cultivars, however, we probably escaped relatively unscathed. But ask me again in April, and the winter is not over yet. Thanks to for the data. JC

Amesbury, -5
Ashfield, -11
Belchertown, -6
Belchertown-2, -8
Bolton, -7
Boston (Weld Hill), -3
Deerfield, -11
Dracut, -12
E. Bridgewater, -12
Harvard, -11
Northboro, -6
Seekonk, -4
Sharon, -11
S. Deerfield, -11
Stow (Shelburne), -11
Stow, -11
Tyngsboro, -13
Waltham (UMass), -7
Westfield, -13
Pittstown (NJ), 1
Calais (VT), -20

Update: For what it's worth, here are the past week and past month temperature graphs. Note the 60+ a little over 2 weeks ago.