What are crab apples?

One one end of my son’s kindergarten is a tall, spreading tree that’s been bearing little green apples for a while now.  Just about every day we contemplate this tree, because he passes it on the way around the back of the building to wave goodbye to his friends.  One one particular day, though, he stopped to really look at the tree.  And at the little green apples covering the ground around the trunk.  Then he stoops and picks one up.  “Can I take this home?” he asks.

I’m not surprised by the questions.  He’s five, after all.  He collects things.  Rocks.  Acorns.  Sticks.  Anything that catches his eye as interesting or unusual or just fun.  All of it comes home with him, sometimes to end up in his “treasure box” and sometimes to be quietly disposed of by mommy and daddy.  “No,” I tell him.  “They’re yucky.”

He nods sagely at that.  “And poisonous?” he asks, voice half worried and half hopeful.

“I don’t think so,” I tell him.  “But don’t eat one.  They don’t taste good.”  I say that with confidence, although I’ve never actually tried to eat one.

He tosses the apple aside.  “Well,” he declares with confidence, “I think they’re poisonous.”  Then he looks at the tree again.  “Why do they grow it?”

I shrug.  “Because it looks nice.”

Crab Apple Trees

Crab apple trees (also known as “crabapple trees” and “wild apple trees” are one of between 30 and 55 (depending on how  you classify them) species of the genus Malus, making them close relatives of the domestic apple tree (Malus pumila) that provides the apples we eat.  They are small to medium trees, with five to ten petaled flowers (depending on species) that develop into fruit that is an average of two inches in diameter.  The fruit is edible and non-poisonous, but is often quite sour due to high concentrations of malic acid – the same acid that makes grapes ‘tangy’ and Sweetarts ‘sour’.

Why would we grow crabapples?

Reasons for cultivating crabapples vary.  You’ll find them planted as ornamental trees because the flowers (and even the fruit) and considered pretty and worth the effort of cleaning up the fallen fruit.  The small (for a tree) size also means they reach full size quickly (again, for a tree).  This makes them good choices for planting a wind break, or for use in small areas, or for planting when power lines may be overhead.

Crabapples don’t have a lot of commercial uses, as the fruit tends to be sour.  However, the fruit is a good source of pectin (used as a gelling and thickening agent) and the wood provides a pleasant smell when burned (and is one of the sources of “apple wood smoking”).  Also, some commercial apple farms plant crabapples to allow cross-pollination with domestic apples and to serve as rootstock when grafting limbs from prized apple trees.  I also found some claims that crabapple preserves are quite tasty and that adding some crabapple juice to apple cider adds an interesting flavor, but I can’t vouch for that – “interesting” can cover a lot of sins with food, after all.

So they have uses.  But that doesn’t mean my son can bring the crabapples home.