Sunday, March 5, 2017

Revenge of the Seeds

'Bradford' pear flowers with old fruit
Pears that have seeded into the wild from cultivated stock are blooming now. These are the trees that were sold as ‘Bradford’ pears (Pyrus calleryana) and a few other names. You can spot these offspring in vacant lots and sunny roadsides – they are generally upright and have flowers in clusters of white/cream. If you were to examine them up close, they might have a musky smell and sport occasional thorns (a trait that was bred out of ‘Bradford’ but remained in its genes).

As many people know, these pears were originally promoted as sterile plants. They would not cross pollinate with each other and therefore would not produce any fruits (or seeds). However, their weak branch structure led to excessive limb damage and nurserymen worked to produce stronger, better versions, later sold as ‘Aristocrat,’ ‘Chanticleer’ and others. Unfortunately, the introduction of these other cultivars meant that cross-pollination with the older ‘Bradford’ pears would result in small but viable fruits.

'Bradford' pear fruit
This ability to bear fruit was painfully obvious in my neighborhood when a neighbor with two pears decided to plant 3 more and he selected a different cultivar. The two older trees had only occasionally set small amounts of fruit (another neighbor, further away, has some wild ones and the occasional bee was able to fly far enough to pollinate a few flowers). When the 3 new trees were planted in close proximity to his existing ones, the fruit production exploded. He now had 5 trees producing heavy amounts of fruit.

It wasn’t long before seedlings started popping up in the yard across the street from his trees – dozens of them and no doubt many more elsewhere that were not as visible.

When he first planted the trees, I mentioned that they were not a good choice. After a couple years, I mentioned that they were setting a lot of fruit and spreading into the neighborhood. It wasn’t until they affected his ability to grow lush grass (they cast shade) that he decided that maybe they should go. This winter, after they set fruit, he had that set of 3 cut down (original 2 still in place).

Pyrus calleryana seedlings
The cut branches sat in piles on the edge of his property for about a week until he got them cleaned up. Last week, as I walked past, I noticed lush growth there. Always eager to identify things, I bent down to see the source of the growth. It was thousands and thousands of baby pears!

I saw him working in the yard this week and talked to him about the seedlings. He said that he’s planning to tear up the area and lay sod. He also mentioned that he’d like to get rid of the remaining two and asked for suggestions. I told him to check out redbud (Cercis canadensis), and he said he would look it up.  It would be pretty sweet to see those last two go as well! Now to work on the other neighbor.

4 comments:

  1. Those wild Pears are really a problem. I feel so aggravated to see Bradford Pear trees for sale. Redbuds are a good choice.

    ReplyDelete
  2. I've cut one down and it continues to sprout new trees from the roots.

    ReplyDelete
  3. More redbuds!
    You need to start selling t-shirts, you know the kind that would have a Bradford pear tree with a giant red X over it!

    ReplyDelete
  4. Thanks for this explanation! I knew they were invasive, but I didn't realize it had to do with the cross that occurs with cultivars.
    I really appreciate your research presented in such a easy to absorb format!

    ReplyDelete