Growing cucumbers is an almost impossible task lately because of the cucumber beetle problem here. The beetle harbors a bacterial wilt disease in its gut and infects the cucumber vines when it feeds on them. The actual damage done by the beetles is minimal, but their bite is the kiss of death to the vines if they are carrying bacterial wilt (Erwinia tracheiphila). Within a few days the vine starts drooping and eventually dies as the bacterial infection clogs up its vascular system. There is no cure except prevention, and that is difficult. The beetles are tiny and elusive, and they like to hang out inside of the cucumber flowers which makes them difficult to locate. I have not had success controlling them.
This year I am going to try something new and use a kaolin clay product, Surround WP. Surround is a finely ground white clay that is used to coat the leaves and stem of the plants you want to protect. It is not a pesticide but a deterrent to insect activity. It comes in a 25-pound bag and is mixed with water to form a slurry, which is either sprayed or used as a dip. Since I started my cucumbers inside in peat strips, I chose to dip the plants in a bucket of Surround for first application. Later on I will have to spray the plants to reapply it after a rain.
I used a small one gallon bucket to mix the slurry, adding water to the powder and stirring to get it wetted. I tried a stick at first but found my fingers were more effective. You want the slurry thin enough that it drips but does not run off the leaves.
When ready to plant, I took a peat strip, broke off the top edges so they will not stick out of the soil, and swirled the plant in the clay slurry.
Once the plant is reasonably coated, it is ready to put in the ground, looking like a white ghost. I wondered if the clay has a negative effect on the plant, but it apparently does not and has some advantages. The clay breathes and sunlight can get through so photosynthesis is not affected. At the same time, the clay prevents sunburn of new plants and reduces transplant shock.
Here is a row of newly planted Homemade Pickles, a pickling cucumber, looking quite ghostly.
The most difficult to plant were the Monika cukes above, a pickler from Poland. The plants were very compact so it was difficult to plant them without soil getting on and sticking to the wet clay.
Time will tell if this type of treatment works. UMass seems to think it does. It is important to start it at plant out because cucumbers are most susceptible when they are young (less than 5 sets of true leaves). Surround is widely used by commercial growers and both Johnnys and High Mowing Seeds use it in their fields. It is widely used in orchards and vineyards. And it is also useful for other plants and pests, such as flea beetles on eggplant, thrips on onions and squash vine borers and squash bugs, so I may apply it elsewhere in the garden, once I get a sprayer than can handle a wettable powder.
Good luck. It will be interesting to see how it does for you. When I lived in Winchester I never ever got wilt. But here it abounds. I tend to keep a row cover on my cukes until they really start running well Then I carefully tie them to the trellis trying not to break them. It isn't a perfect solution but I get a lot of cukes at least. The vine borers on the other hand will find any opening in my white row cover. I think the clay would only vaguely help them. I've also tried aluminum foil on those with no luck.
ReplyDeleteI considered it but I don't have the space to do what you do. You can see my cukes are sharing beds with the chard and beets. The cukes in teh chard bed will stay covered for a few more weeks until they have to be trellised. And I think the clay may be effective on the borer moths. They have to lay an egg on the stem and if it is covered in clay, that will deter them Trick is to make sure the stems are completely covered.
DeleteMy cucumber beetles got out of hand back in 2012/2013. That's when I began sticking them to duct tape. I got pretty good at it. One option is to hold the tape below and get them when they drop. I liked that better than sticky traps with lures which work, but also catch good pollinators. Last year I only saw four beetles. FOUR! Success!
ReplyDeleteHappy that worked for you. I actually see very few beetles but it doesn't matter, one bite can doom a vine.
DeleteI really hope this works for you. I didn't realize that the clay was a deterrent for the vine borer - they are a big problem around here. I had been meaning to get a sprayer for the milk spray that I use on cucumbers, squash and tomatoes so I'll have to keep in mind that it would be useful to get one that is also capable of spraying Surround.
ReplyDeleteDepending on what happens with my plum and cherry harvest this year, I may try Surround next year. When I last had fruit from these trees (2 years ago), many of them were infested with the plum curculio & I think this is the only organic defense available. My trees are pretty big, though, and in my front yard - I wonder what the neighbours would think of a couple of ghost trees.
You also have to consider the residue it might leave on your fruit. BTW, it supposedly also protects against powdery mildew.
DeleteHope that works for you. It's interesting how every region has it's particular bug and/or disease problem. Cucumber and squash beetles aren't much of a problem here, but I've noticed the Bagrada Bug activity picking up as the weather warms up. It going into year 2 with this new exotic pest, so I'm not sure what problems are in store for the garden. It has been devastating for commercial growers in the area.
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ReplyDeleteThanks for sharing such beautiful information with us. I hope you will share some more information about cucumber. Please keep sharing. Health Is A Life
ReplyDeleteAlthough I started using the kaolin clay as a spray last year with great results, ill be dipping my seedlings this weekend at transplant.
ReplyDeleteAll the squash and cukes.thank you.