Banishing Bitter Pit -- Kudos to Calcium

Before we moved into our current home I had plenty of experience with apple anthracnose and scab and wooly apple aphid and codling moth. In the seven years since our move I have become way too familiar with apple maggot and with bitter pit. Words cannot adequately express my disdain and frustration for the beastly little apple maggot, (at some point I might try), but up until this year equally venomous words were saved for bitter pit, the scourge of my apple crop.

I say "up until this year" because this summer I began to spray the apples with liquid calcium and now notice a remarkable improvement in fruit quality.

Bitter pit is a fruit development problem linked to calcium deficiency, possibly to soil moisture — as well as to fruit variety. I had barely even heard of it until we moved to our current home in 2008. Here our lone apple tree produced hundreds (hundreds!) of early yellow-green apples pockmarked by dozens of small brown spotty indentations. These “bitter pits”, where fruit cells have shriveled and died, affects both the fruit flavor and the storage.

Following recommendations, this past year I began spraying the fruit on my trees with liquid calcium. By now this tree supports seven different varieties (a different story) and some types seem more prone to bitter pit damage. Our 2016 season had a wetter than average spring after an excellent fruit set; I cannot say whether it was my several applications of liquid calcium or because the fruit was better hydrated, or how much the two are related. I just know that all the varieties of apples I am growing were far cleaner in this year of spraying calcium than in the past.

The One-tree Orchard

When we moved to our current address several years ago, in the back grew one apple tree. It was a misshapen, poorly pruned tree, (at least by my criteria). And though the tree was highly productive, the apples were terrible -- a poster child for bitter pit. I'll say more about bitter pit in another blog, but the poor apple quality drove me to finally stop being afraid of grafting. I determined that I could add another variety of apple to the tree that I'd prefer, replace the apple I didn't like, (couldn't eat) with one tasty and disease free.

About five years ago I finally took the plunge, buying scion wood from Michael Dolan of Burnt Ridge Nursery, a guru of tree and shrub edibles and an anchor of the Olympia Farmer's Market. I selected five apple varieties:

• Red Gravenstein
• Liberty
• Golden Russet
• Spitzenberg
• Tydeman's Early

After deciding how I'd partition the tree and how I'd mark the different varieties, (colored tape), I starting grafting, one variety per section. I tested several different techniques and achieved adequate success -- maybe 50% each. The next summer a friend asked if I could save some fruit wood from a tree likely to be cut down, and I was able to successfully bud graft a sixth variety -- we think it is "Burgundy" -- into the tree. Since then I've grafted more of each into the tree and appear to mostly have a good showing; my rate of success in improving.

I am determined to reduce further the original tree. I'll have to make several harsh stub cuts, and onto each stub I will graft more stock. While I will not fully transform the tree, I hope to make the original tree significantly less dominant. I want to add one more variety, one I found in an orchard that seems to ripen late and keep well; it will probably replace Tydeman's Early, which on my tree is not thriving. Watch for updates.