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invasives

    Date Posted: Fri, Aug 27 - 3:36 pm

    Question

  • 1) I have rampant overgrowth of wisteria, as well as more limited poison oak in an area covered by pine straw, ornamentals on perimeter of area, but worst parts are distant from these bushes. 2) Also widespread seeding from a mimosa (since cut down, but too late) throughout the front lawn. I'm averse to using Round-Up, and wonder if you can offer solutions and guidance. Many thanks! Catherine Davis
  • Answer

  • Hello there, There's a lot do here. The wisteria should probably be dug up and put in the trash. They are rampant vines. I have seen some people do an excellent job of training them and keeping them in bounds. It all depends on your maintenance tolerance. If they are left to run wild they will climb trees and kill them over time. The poison oak (which I think is actually native but no one actually wants it in their yard) should probably be smothered. I understand you not wanting to using Round-up or a similar product, I wouldn't use it either. If they are young and small plants depriving them of sunlight, water and nutrients will over time kill them off. It could take several months but doing it now with this hot weather will help the soil heat up to kill the plants. Tarps, cardboard, plastic sheeting, these should all work. This process works best in sunny sites, you didn't mention the exposure. I've also had success using straight white vinegar on any plants that survive and re-sprout. And of course, be sure to wear protective clothing, head to foot, any time you are working with poison oak or ivy and put the clothes in your waster with hot water when you're done. As far as the mimosa seedlings, I can only imagine hand pulling them. I don't know the area in question but using vinegar in your lawn will damage the grass and I'm sure you don't want that. Hand pulling is one of the most effective methods to use when possible because you can often get the root of the plant out. Having a good thick ground cover is the best bet for keeping out all those unwanted plants. If there's a vacancy, they'll occupy it!! Best of luck Catherine!!

Squash Vine Borers

    Date Posted: Tue, Aug 24 - 1:57 am

    Question

  • Hi there! Thank you so much for doing this! I have a couple questions on squash vine borers, which have been a HUGE issue in my garden this year. I have been surgically removing the larvae from my curcurbit vines every few days for over two months now (along the way losing both of my zucchini plants and one patty pan squash plant; now I have one patty pan and 4 pumpkin plants remaining). My questions are: How much longer should I expect new larvae to bore into my plants? And is there anything I can do next season to organically prevent these pests (or perhaps control them in a less laborious fashion!)?
  • Answer

  • Hello! Thank you for your question. It sounds like you have had a challenging season with this difficult pest. Your surgical removal of the larvae is one part of the solution, and it sounds like you have mastered that particular process. There are other things you can do as well. To answer your first question, it is important to understand the lifecycle of the squash vine borer. Eggs will first appear in our area in May, will hatch in early summer, and then the larvae will bore into the squash stem to feed for up to 4 weeks. When the larvae are mature at 4-6 weeks, they will leave the vine and the dig 1-2 inches in the soil to pupate. In our climate, we can sometimes have 2 generations of larvae in a season. So unfortunately, once infested, this pest can present a problem for most of the growing season. In addition to the surgical removal process of the larvae in the stems, you can also use an organically approved insecticide such as Spinosad or Bacillus thuringiensis (Bt). Apply the product on the leaf stems and the main stem of the plant - do not spray the flowers. Apply one of these insecticides once per week during the growing season. It will kill the borer's eggs and larvae quickly. Again, these are organically approved products, and we recommend staying away from any synthetic, non-organic insecticides. Another method for prevention early in the season is to cover the young plants with a floating row cover until flowering occurs. The row cover will keep out the insect in the critical early part of the season, and will still allow sun, water, and air to get to the plant. Once flowering begins, remove the cover to ensure pollination is not disrupted. If or when you do have an infected vine(s), seal them in a plastic bag before the larvae pupate. This will break the lifecycle of the squash vine borer. And finally, the other important practice is to till under all crop debris after harvest, which also disrupts larvae in the soil, and prevents buildup of the squash borer population. Implementation of these practices should minimize the need for constant surgical removal of the larvae, and yield healthier plants and better crop. Good luck, and please reach out with any other questions!

Yellowing Aster

    Date Posted: Wed, Aug 18 - 1:46 pm

    Question

  • Hi we have a row of fall aster and notice that this year and last as the rest of the plant grows large and bushy the base starts to get yellow and then dries. the plant seems to be getting enough water. Is this normal?
  • Answer

  • Good morning, and thank you for your question! My first thought is that you may have a watering issue. I’m assuming your aster plants otherwise have normal growth, are not stunted, and bloom well. Asters do prefer well-draining soil and like to keep well watered. However, they do not like overhead watering or sprinkling. Doing so can result in development of a fungal disease. Watering should be done at the base of the plant where fungus would first develop. It also helps to use a good organic mulch around your aster plants to help retain moisture and prevent splash to the lower leaves which can cause the yellowing. As a side note, be on the lookout for leafhoppers on your aster. They can spread bacterial disease (phytoplasma), which is a more serious problem to deal with, but with this you would likely notice other symptoms such as stunted growth and deformed flowers as well. If those symptoms develop, the plants would need to be removed as there is no cure. It does not sound like you are experiencing these specific problems with your aster, and proper watering and mulching would be the best first steps to implement. Good luck with this, and let us know if further symptoms develop.