Carrie Barre-LiBaire's Gardening Column

Down to Earth Gardening

Of all the questions I get asked and the specimens that are brought in to the Extension office, I would have to say that a quarter of these are about apple trees and their fruit. This confirms to me why I don’t grow apples-I just don’t have the time or patience! I have seen many damaged apples come in the past week, so if your apples are less than perfect it’s most likely it was infected in the spring by one of three insects and this has turned them, as someone on the phone described it-“wormy”.

The plum curculio is a small insect that has a nose like a trunk. It causes damage when it sticks that appendage into the top of newly set fruit to lay eggs. You can see the inject mark pretty easily on the fruit. The larvae then tunnel around the inside of the apple causing a very dimpled apple to form and the insides to turn brown. There is also an apple curculio that is becoming either more of a threat or we’re finding that perhaps plum curculio was being diagnosed for damage when it really may have been the apple curculio. Confusing, I know. If you have curculio damage there’s really not much to do this year other than making sure you pick up all fruit from the ground. The emerging apple/plum curculios over winter in the ground to reemerge the next spring for another round. In the spring, you can spray your tree with a home orchard/edible fruit insecticide when the blossom petals are falling, which is a two-day window most years.

The famous apple maggot is another destroyer of fruit. The apple maggot adult fly looks somewhat like a deer fly. This nasty thing also pierces the newly set fruit to lay eggs. And we all know what fly eggs mean-maggots. It seems the best environmentally friendly option in preventing apple maggots is to bag your apples before the fourth of July. If you’re not familiar with the practice, you just fasten clear plastic baggies over the young fruit. Secure with twist ties and be sure to cut a drip hole in one corner so moisture doesn’t collect in the bag and steam your apples.

There are of course many other problems that can affect apple trees. It makes perfect sense to me that apples are in the same plant family as roses. That’s one high maintenance plant that I attempt to keep alive despite repeated attacks by fungal diseases and sawfly larvae.

Another interesting thing about apples; the origination of the Minnesota Horticultural Society came about from the early settlers of Minnesota trying to get apple trees to grow here. It’s quite amusing to read about the trials and tribulations of these settlers from warmer climates. Most of the entries are like this “we planted 150 apple trees, 146 didn’t make it through the winter, 3 were eaten by gophers and one was split in two in an ice storm.” I guess some things never change.

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