Return to the Fruit & Orchards Forum | Post a Follow-Up

When to thin apples??

Posted by oldryder (4,MN) (My Page) on
Wed, Jun 5, 13 at 18:21

My apples are almost done blooming. Do I need to wait until the apples begin to form or can I thin the remainder of the flowers?

It's been a long wait (5 years) but I'm gong to have a LOT of apples this year barring any calamity.

Follow-Up Postings:

RE: When to thin apples??

When they're the size of small olives.
Keep the largest, most perfect one of each cluster.

RE: When to thin apples??

Sooner is better. As I understand it, you can limit/control biennialism in apples by getting the aplets off immediately, even if that means removing blossoms. Your ultimate goal is to space apples to about one every 9", or thumbtip to pinkytip on a wide opened hand. But many people leave some cushion, as there will be June drop of the unpollinated apples. If you spray with carbaryl (Sevin) it will do a lot of thinning for you, maybe too much. And a certain number of apples will be damaged by bugs and birds and such.

RE: When to thin apples??

I start to thin when the difference between the pollinated and the unpollinated fruit becomes evident, as the stems of the unpollinated apples turn yellow and the fruits drop.

RE: When to thin apples??

I have thinned entire clusters of flowers on varieties that are stubbornly biennial. Generally, if you thin within 3 weeks of petal fall you get most of the benefits. By about 9 days after you should have a good idea about what has set.

I believe weather has a big affect on how well this will happen- if the tree can't store a lot of energy due to cool wet weather during bloom through early post petal fall it may reject much of the crop even if flowers were pollinated.

RE: When to thin apples??

  • Posted by fruitnut z7b-8a,4500ft SW TX (My Page) on
    Thu, Jun 6, 13 at 10:46

The people using chemical apple thinners have taught me a lot about weather and fruit drop. During those first weeks after bloom there is a large effect of carbohydrate levels in the tree vs fruit number and growth rate. Things increasing photosynthesis and carbohydrates hold more fruit on the tree. If energy levels in the tree fall, fruit falls off more and sooner.

Their thinners are much more effective during warm cloudy weather than during cool weather with sunny conditions. Warm weather increases fruit growth and carbohydrate needs. Clouds reduce carbohydrates and the fruit falls off.

A few days under total shade will knock all the fruit off the tree.

RE: When to thin apples??

Fruitnut, that's good information. I bagged a couple dozen apples on my first-fruiting Fuji, and I can see that some of them dropped off overnite. We've had nothing but constant rain and overcast since the beginning of May.

And, of course, it's June. Since the Fuji was the first apple I thinned and bagged, I'm seeing that the dropped fruits are all as small as they were when I did it, failed to develop.

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Fruit & Orchards Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here