The Cherry Slug

July 12, 2016 by Tilly 10 Comments

Having fruit trees is great! Yep, so easy, so hands-off, so ‘plant it and forget it,’ — NOT!

Fruit trees are a lot of work, and I mean A LOT!  There are so many things that can wrong, and most likely if it can go wrong, it will go wrong.

Of course the first issue when planting a new fruit tree is the stress of wondering whether or not the tree will survive the initial shock of being planted in your yard. For weeks, even months, you can keep vigil over your little trees not knowing if they are comfortable in their new home, if their roots have enough growing room, if the soil is to their liking. It’s normal for some leaf loss, but how much is really to be expected? 10%? 20%? 50%? Should I count how many leaves I started with to keep an accurate measure so as to know when I should be concerned?

Then there is the threat from Mother Nature’s cute little critters should you happen to have any fruit on the branches. Keeping the birds at bay is a full-time job. You can tie little tin plates to the branches with a washer hanging in the middle to scare them off, put up a scarecrow, or if you have the time just stand in the yard with a broom and shoo them off should they dare try to sneak some lunch from your branches.

And the squirrels, now they are a bit more stealthy when it comes to raiding your tree and eating the fruit. They sneak along the ground, sometimes hidden in the grass and dart up the tree trunk into the branches. This is where a good dog comes in handy but unless you plan on keeping the dog tied up next to the tree 24/7, there’s really no way to squirrel-proof the yard and tree.

Overall however animals are really the least of your worries. It’s the disease and insects that are the real fruit tree killers. These can attack the roots, the trunk, the branches, the leaves, and the fruit. Every part of the tree is susceptible to fungus, bacteria, infestation, and rot. And every one of these things require different types of measures to control or remedy.

For about 15 years we have had an Italian plum tree in our yard. Almost from day one we have been fighting brown rot. This occurs when fruit falls from the tree, rots, and then the rotting liquids get into the soil and infect the tree. For all our efforts of picking the fruit up as it falls the ground, there is no way really to ensure that every last plum gets picked up. Therefore we learned to begin spraying our tree before it begins blooming and continue until all the fruit is done. The tree still has brown rot, but will still produce fruit and continues to limp its way from season to season.

This year we decided to add a tart cherry, a sweet cherry, and a peach tree to the backyard. At the time I was excited about the prospect of having more fruit trees in the yard and hopefully in a year or two more fruit. Well, things have not gone so easily and my hopes for healthy trees has quickly diminished.

First one of the cherry trees didn’t survive the transplanting. Within a month it was dead and we were digging it out and replacing it. If this were the only issue, I could deal with that, but that was just the beginning.

Next the cherry tree that survived the initial planting decided to lose more than 50% of its leaves more than a month after it was planted. Two branches are now dead on the tree, leaving three lower branches still alive. At this point the tree has not lost any additional leaves for two months and we don’t know why the two upper branches withered and died, so we are playing the waiting game.

Then, all the fruit that actually survived the planting and began to grow were taken by the birds. Our trees are too small right now to interest the squirrels so at least there we dodged the bullet. But the birds certainly made up for it. I did put some nice noise making tin pans on the branches, but it was too late and no fruit will be harvested from the trees this year. Actually I didn’t expect any fruit, but watching the birds make short work of the tiny cherries and peaches opened my eyes to how difficult it is going to be to get a harvest in the future.

Not allowing me to relax at all, the next challenge was dealing with leaf spot on all three trees. In my research I learned this was a bacterial or fungal infection of some kind and very difficult to get rid of, but controllable. So we began spraying the trees so they wouldn’t lose all their leaves.

For about a week everything was good. No more leaf damage, no more leaf loss, and the trees actually looked like they were getting a little bigger.

Yesterday, though, things took a turn for the worse. As I was watering the garden I noticed that many, nearly most, of the leaves on the tart cherry tree (the one that had already lost more than 50% of its leaves earlier in the season) had huge portions of the remaining leaves on the tree eaten away. A closer look resulted in me finding this:

I snipped off the leaf and took to Hubby and asked him to investigate. Within minutes he was back and told me we had Pear or Cherry Slugs. Wonderful, just what we needed.

Apparently Cherry Slugs are the soft skinned larvae of the glossy black sawfly Caliroa Cerasi. Isn’t that nice? The sawfly lays eggs on the leaves and they hatch into the slugs. Interesting enough, as I was examining the tree for more slugs, there were a bunch of little black flies all over the tree as well. I guess these little guys have come home to roost.

Once the slugs reach full size they drop to the ground where they dig themselves into the soil to pupate. Then adults emerge, flying to the leaves to lay more eggs. This happens twice each year, getting worse the second time around if not nipped in the bud during the first cycle.

Although the tart cherry tree had lots of damage, and fairly quickly I might add because I’d just checked the tree two days before and there weren’t any slugs at that time (the eggs obviously hadn’t hatched), the sweet cherry tree had only one or two slugs on it. Hubby told me that there were some very easy solutions to this problem. The easiest was to just squish the slugs on the leaves.

Squish the slugs? With my fingers? Like that was going to happen.

Yes I changed dirty diapers, caught my kids throw-up, and have done some pretty gross things as a parent through the years, but somehow squashing a bug goes above and beyond for me. This is just one of those jobs meant for — Hubby.

So he examined the tree and quickly squished all he could find.

Next Hubby told me to mix up a bottle of water with a little dish-washing soap. Spraying this on the leaves will supposedly dry-up the slugs. They are very sensitive to the soap, so it presumably would kill anything Hubby missed.

I did this, happily. Not only did the tree get all squeaky clean, but it had a slight hint of lemons afterward. I did find one slug on a leaf as I sprayed and when it got sprayed, it stood up on its rear for a moment and then fell back to the leaf, flattening out in a pool of water. Well, at least this was working.

So as to make sure the slugs didn’t escape if they happened to fall to the ground, I also sprayed the ground around the tree generously.

Other remedies for these little guys include dusting the leaves with wood ash, chalk, flour, or powdered clay. Also, blasting the leaves with a garden hose should knock most of the slugs from the leaves, but then you still have the chance of them climbing back up the tree. This can be averted by generously spreading some vaseline around the base of the trunk of the tree.

So my trees have now been washed, greased, and powdered — like my kids when they were babies. I guess my trees are my new babies.

Oh, and although these slugs are reportedly only attracted to pear and cherry trees and I could find no mention of them infesting other fruit trees, I found flies and slugs on the peach tree this morning. I guess we’ll have to expand the name to Pear, Cherry and Peach Slugs!

For now, my trees are enjoying another hot and humid day, sticky from their morning bath of water and dish soap and I’m preparing some flour to sprinkle on the leaves tonight, just to cover all the bases. I’d have to say that growing fruit trees is definitely not for the faint at heart, but if these little trees make it and produce like our plum tree did the past three years (averaging more than 200 pounds of usable fruit a year), it will all be worth it, and this is why I am — Simply Grateful.