Tag Archives: Pollination

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?

 

A crab apple tree helps the pollen go down
John Downie Crab Apples

Ripe John Downie Crab Apples

Crab apple trees improve apple yields and if you have the space in your orchard, you might like to plant a variety such as Malus John Downie or Malus Evereste in November. These are both crab apples that flower pretty much all the way through the fruiting apple flowering season and are sufficiently related to domestic apples to be perfect pollination partners. Because of their long flowering period and viable pollen, you will never have to worry about apple pollination groups again which makes growing fruit trees even more fun….

One John Downie or Evereste crab apple will permit the pollination of an orchard of anything up to 40-50 trees. What is better is that both these varieties also carry masses of crabs that will enable you to make enough crab apple jelly to keep you family going all year. Evereste is probably the heavier cropper of the two, has a semi-weeping habit when laden with fruit which look like perfect miniature apples.  John Downie’s crabs, on the other hand, are probably more decorative.

When planting a crab apple as a pollinating tree, try to get it as close to the centre of the orchard as possible. Obviously, if you have a large orchard and need more than on pollinator, you will want to “sprinkle” them around a bit.  However, (subject to our advice below) it is a bad idea to plant in the hole left by an apple tree that has died or been grubbed out as apples, being members of the rose family, suffer from replant disease.

Our (non guaranteed opinion) based on testing in our own orchard is that replant disease can be overcome with the use of Rootgrow. This is a natural preparation that contains mycorrhizal fungi. These are fungi that occur naturally and that form a beneficial association with plant root systems. They provide water the the plant in exchange of receiving its waste starches.  The fungi grow incredibly fast and can effectively increase a tree’s root system several hundred times in the months following planting.  By the way, whether you are worried about replant disease or not, all fruit trees will establish faster and crop more heavily if you plant them with Rootgrow.  At the time of writing it is the only planting aid of its type that is recommended by the Royal Horticultural Society. We think it is a remarkable product and a real boon to gardeners of all types, not just those who grow fruit trees.

Scrumptious Apple Trees (and Scrumptious Apples)

Scrumptious apple trees are another apple breeding success. They are the “children” of Hugh Ermen – the best producer of new apple varieties in the UK.  The man is a genius (and proof that amateurs can win) and has a list of apples to his name of which perhaps the most well known are Limelight, Red Devil and Winter Gem. Scrumptious is a lovely apple, nearly full red, with crisp firm flesh when picked.  It is relatively early, ripening in September. Unusually for an early apple, Scrumptious holds well on the tree for at least four weeks and will keep for a further couple of weeks if you store it in a cool place.   For a relatively early apple, these are brilliant qualities (none of those Discoveries all ripening on the same day…). It is also sensational eating straight off the tree. Just another apple for the fruit trees website.

Scrumptious apple trees are self fertile (but remember in the apple world self fertile means they carry fruit without needing another variety of apple as a pollinator but crops are always better if cross pollination occurs). Unlike Discovery which is one of Scrumptious’ parents, it fruits over an extended period. For those of us who suffer from the cold, its blossom handles spring frosts pretty well making it a good choice for frost pockets and colder parts of the UK.

For the more technical, Scrumptious apple trees belong in group C for pollination. They can therefore be pollinated by any (non-triploid) apple in pollination groups B, C or D. Its parentage is Golden Delicious and Discovery and it is therefore preferable (but not essential to select a pollinator that does not also have either of those varieties as a parent). It is a spur fruiting apple tree, which means pruning is straightforward and which also means that it can be grown as a step-over, a cordon or as an espalier as well as the more usual bush and half standard shapes. It performs well on semi-vigorous MM106 and semi-dwarfing M9 rootstocks which means it can fit into any garden or orchard capable of housing a fruit tree. Bare-root apple trees should be planted between November and the end of April while container grown trees – which tend to be more expensive- can be bought at any time of year.