Return to the Container Gardening Forum | Post a Follow-Up

 o
Cupping leaves--too wet or too dry?

Posted by marc5 z5OH (My Page) on
Sat, May 25, 13 at 14:56

I'm hoping you all can help me determine what is causing my pawpaw leaves to cup up and curl. Please see photos. Is it too wet or too dry? I was trying to use moderate watering. I am experimenting with several mixes. Note that one is a 1:1 peat:sand mix, the other is in 5:1:1. The worst tree is in the peat sand mix, and perhaps that is telling us something. A third mix used is 9:1 pine bark:compost, and those trees, while some are cupping, look the best. Again, another clue? While my first reaction to the leaves is that they look dry, perhaps because the faster drying mixes look better, is there too much moisture?

I am using dowels to help me with moisture levels, and the bottom half of the containers seem plenty moist. The containers are Rootmaker, and the mixes contain Osmocote at a rate of 12 lb/cubic yard--about 2 tabs/gallon. Small amounts of micronutrients are also in the mix. Some acid is being injected into the water. Newly-germinated pawpaws in 5:1:1 in Rootmaker 18s look great. Thank you for any ideas.

Marc

Pawpaw in peat:sand photo 20130524_125532_zps6c728d9c.jpg

Pawpaw in 5:1:1 photo 20130525_140059_zpsc7d2d14a.jpg


Follow-Up Postings:

 o
RE: Cupping leaves--too wet or too dry?

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Mon, May 27, 13 at 12:31

Either Ca or Mg deficiencies often cause deformities in the shape of cupping (did you add dolomite to your mixes? does your fertilizer contain Ca/Mg?). Deficiencies of zinc and molybdenum can also cause the same distortions. Too much or not enough water can do it, too.

Any chance the plants caught any herbicide over spray? What Osmocote formulation did you use? Selecting a product that matches your zone and plant requirements can have a considerable impact on what benefits are gained by your plants.

Al


 o
RE: Cupping leaves--too wet or too dry?

Al, thank you for your response. You are the foundation of this forum. I did not add dolomite to the mixes, as my water has plenty of Ca (78 mg/L) and Mg (30 mg/L). To the mix I added Florikan MIV Meg-Iron, which has .09% Zn and .06% Mo. I added 1 lb./ cu. yd, or about 1/6 tab per gallon of mix. The Osmocote in the mix was Classic 18-6-12 (I know you like this ratio) in 8-9 months. There is little chance of herbicide spray, as the plants are in a high tunnel. Could it be too much or too little water? The problem with plants seems to be that too much or too little water can result in similar symptoms.

Unless I come up with a definitive answer, I am hoping an experiment will shed some light. I am placing two similar plants side by side. For one I am cutting back on water. For the other I will increase the watering amount slightly. We will see which looks better over time. I hope they both do not die!

Thank you again,
Marc


 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 Container Gardening 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