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barbaraincalif

Use of Dimension (dithiopyr) pre-emergent among conifers

barbaraincalif
10 years ago

The weeds have gotten away from us this spring. While removing grasses and most broadleafs before they set seed is just a minor inconvenience, it's the quickly re-seeding Spotted Spurge (Euphorbia sp.) and Oxalis that are our weed villains. After visiting our local Ag/ professional landscape chemical supply we decided on Dimension 2EW spray, intending to mix it with Roundup and spot spray the offenders. It is also labeled for use in container grown stock, so I just may try it alone there too.

The Problem: no Abies, Cedrus, or Ginkgo are mentioned on the label, neither is Cupressus macrocarpa (though Cupressus sempervirens is).

The Question: What experience have you had using Dimension (dithiopyr) with conifers? Have you observed any damage to the unlisted genus?

Thanks for the help,
Barbara

Comments (7)

  • jth97381
    10 years ago

    I would caution against application where the Chemical comes into contact with the new foliage. Few liquid pre-emergents are safe for spring applications. I do not have experience with this perticular chemical. I like granulars on spring growth. Apply when foliage is dry and then sweep or bkow off with a leaf blower, then water in.

    Just becareful and good luck.

  • jth97381
    10 years ago

    I would caution against application where the Chemical comes into contact with the new foliage. Few liquid pre-emergents are safe for spring applications. I do not have experience with this perticular chemical. I like granulars on spring growth. Apply when foliage is dry and then sweep or bkow off with a leaf blower, then water in.

    Just becareful and good luck.

  • outback63 Dennison
    10 years ago

    Barbara,

    I have not tried this either.

    Why not do a small test area before you commit. Does this product have a web site to contact?

    I use roundup in my islands and if close to a plant dig it.

    I had an epidemic of Spotted Spurge last Summer. I have plans in place to catch it early walking the garden every other day to eradicate it. In the lawn mow high. Applying winter fert will ensure a heavy thick grass to choke it out.

    I also see an epidemic of Oxalis beginning this year. The red you need to spray. Yellow I hand pull and scrape beds to kill it when small..

    Of course I am sure you know we import this stuff in the potted plants we buy. I always do a through check before planting . It is always there. and removed. Wasn't smart enough in my early years to know that. Now I am paying for it.

    Good luck. Let us know, if used, how good and safe it is.

    Dave

  • barbaraincalif
    Original Author
    10 years ago

    Great ideas...thank you! We'll stay away from the unlisted plants ('we' as in my husband does the spraying), and since it will be tank mixed with Roundup will definitely keep it off the foliage.

    I have some purchased seedlings of Abies and Cedrus in pots so can experiment on a few of them.

    The best non-chemical way I have found to get rid of spotted spurge is to mulch heavily, and then cover any that appear with another layer of mulch. It's my understanding that the seeds need light to sprout. My garden is all torn up from re-doing some areas and working on the irrigation system, with mulching next on the list of things to do.

    Thanks again,
    Barbara

  • Sara Malone Zone 9b
    10 years ago

    The spurge is taking over here this year (every year one weed seems to be the worst) and since almost all of it is in the drainage ditches or the gravel paths I can't mulch it. It is about the only thing that I spray but after reading this thread I'm thinking maybe I'll use pre-emergent to nip the next generation. Barbara do you know what the best timing is in our zone?

    Sara

  • barbaraincalif
    Original Author
    10 years ago

    Sara, attached is a link to the product label.
    As jth97381 mentions late spring isn't ideal, but since neither of us plan to overspray on to foliage plus your application is ditches and paths, there is no better time to apply than now to keep the next generation under control.

    Please let me know what product you use and the results.

    Barbara

    Here is a link that might be useful: Dimension® 2EW Specialty Herbicide Product Label

  • Sara Malone Zone 9b
    10 years ago

    I've always used granular pre-emergent when it was still rainy season and let it get watered in by the rains. I'll check this out, thx Barbara and let you know.

    Sara