Frost Affects Fruit Tree Pollination

We tend to take fruit tree pollination for granted. But it need not be so…. Apple trees with no apples? Pear trees without even a pair of pears?  Was 2012 a fruitless summer for you? Probably and the proof of this article was in the prices and origin of the fruit on the supermarket shelves.  This was a miserable year for fruit that grows on trees.  Great for soft fruits like redcurrants, but dire for topfruit like apples, pears and plums. At times it felt as if this site was pointless….

As in REALLY, TRULY, DESPERATELY bad.  Our orchard of 37 apple trees actually had 5 trees that had no fruit at all – as in none. I have never seen a season as bad as 2012.

The reasons were mainly in the weather.  We had a lovely warm February; unseasonably warm.  Plants all over the UK broke into growth as a result. The buds on the early flowering trees and plants (generally those that flower before they produce their leaves), started to swell as root systems began to pump sap in response to the warmth.  As sap rises, so flower buds force open their protective casings and the water content of soft flowering material increases.

Early March was pretty much the same and then the cold weather came. Once a plant has started into growth it cannot be reversed.  So the second half of March brought bitter cold all over Europe. Here in sunny Somerset we recorded -14C in mid-March.  Temperatures stayed low and the weather stayed dry (you will remember that there was much talk of hosepipe bans). Flower buds were mashed by the freeze and there was not enough moisture around for fruit trees to even try to repair the damage. So flowers were deformed and pollen, such as there was, sterile.

Not all of it of course, just most of it.

The weather also did terrible damage to bumble and mason bee populations – these are the pollinating workhorses of our ecosystem doing far more work than the average honeybee, but without warm hives and friendly beekeepers to feed them on unseasonable days. They emerged too early and then were frozen out.  If you think of honey bees as “busy” you should talk to a mason bee which does in a day what a honey bee can only manage in a week.

So no flowers, no pollen and no pollinators. A fruitless summer. Yuck. The blessing such as it was lay in rising water levels that were clearly critically low in March 2012. Hosepipe bans were averted and those plants that rejoice in plentiful water really partied. Watermelons anyone?

 

Comments 1

  1. Ron Martinez

    Your article talks to a point that is the story of my life. Living in the US (New Mexico), we are at the base of the Rocky Mountains at an elevation of about 2,600 meters. Most fruit trees in the area are zapped by frost most years. Well, I exaggerate a bit. We get a crop maybe 2 of 5 years. I’ve been adding new varieties looking at four characteristics. First, I’m trying later blooming varieties. I’m also trying varieties with a longer blooming period (some apple crabs), and I’m trying early blooming varieties that may have already set fruit by the time we get the last frost at the end of May with the hope of some frost tolerance. Another thing I’m trying is grafting multiple varieties onto each tree. This is a bit of insurance that on a bad year, I’ll have at least a few apples to crunch on or to add to my mix of cider. Many of my grafts are now going into the 4th season and will hopefully help me test the results of my efforts over the last few years.

    On a separate but related topic, I’m hoping to make a trip to the UK, especially rural England, to areas that grow apples with an interest in talking to people that grow them and to those of you that may make cider. American cider is sweeter than a soft drink (coke). I’ve had some from Canada that was quite good and dry. Since London, Royalty, and castles don’t get me too excited, I’d like to meet accessible real people who know about apples. If you have any suggestions, I’d like to hear from you. ronemtz at Hotmail dot com.

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