The Squash Vine Borer is your Enemy and Here’s How to Defeat Them.

You’ve started your summer squash and zucchini. The plants look great! A couple of weeks later, the plants start to wilt and some die. What did I do wrong? After careful observation, you notice there is something that looks like wet sawdust at the base of the plant. Plus, you see small holes in the bottom stem. What is going on?

SVBwilt  SVBdamage

Your enemy is the Squash Vine Borer!! (SVB)

svb

The female Squash Vine Borer moth (Melitta curcurbitae) lay brown eggs especially on the stems, just above the soil line.

squash-vine-borers-3-sm  SVB1SVBmating   SVBeggs2

Eggs hatch in 10 days. Once the eggs hatch, they immediately enter the stem, leaving a small hole at the place of entry surrounded by frass (moist sawdust like debris). The larvae (white caterpillars with brown heads) bore into the stem and remain until maturity before pupation (the transformation of the larvae to a pupa(in a cocoon)). They will now stay in the soil (usually 1″-2″) and over winter .

squash-vine-borers-4    SVBmoth_pupae

Squash Vine Borer moths emerge from the ground from early spring through mid-summer. The moth looks like a wasp and is a half inch long. The wings are clear and look like a windowpane. Unlike other moths, this one flies during the day and makes a buzzing sound.

Now that you have identified the enemy, what are your weapons of warfare?

  • A preemptive strategy would be to use a floating row cover (sheer, light weight fabric that is placed over a crop to protect from insects). It is secured in place to prevent insects from damaging the crop. The row cover is put on at the time of planting until the plants begin to flower. Squash crops require insect pollination.
  • Monitor by using a yellow colored bucket trap with water, placed near the newly planted squash plants. The yellow color attracts the moths.  Traps must be checked daily. Once you’ve found moths in the traps, start looking for stem damage. This indicates the female moth is out laying eggs.
    • SVBtrap
  • Create a barrier on the lower stem by using materials such as aluminum foil. Wrap the foil around the lower stem to confuse and prevent the moth from  laying eggs.
  • Plant a trap crop of early planted Hubbard squash three (3) weeks prior to planting your preferred squash crop.
  • Use succession planting (weather permitting). Have fresh transplants ready to go. A late crop planted after SVB pressure may offer a harvest. Do not plant your late crop where there has been previous pressure from the SVB. Rotate your planting to an unaffected area.
  • SVB resistant varieties of squash, such as Waltham Butternut, offer a solid stemmed variety to thwart the penetration of the larvae. Cucurbita moschata are their least favorite, as they are solid stemmed. Cucurbita pepo are their most favorite, as they are hollow stemmed. Seed catalogs will list this information for each squash seed offered.
  • When a squash plant has been attacked by the squash vine borer, find the borer by looking for the frass or small holes with frass. Carefully slit open the stem and remove the caterpillar. Cover the wound with fresh soil or compost to encourage the re-rooting of the plant.
  • Remove and destroy any plants that are severely wilted or dead immediately. Do not compost these plants!!
  • Sanitation is key! Immediately remove your squash vines after harvest. Do not compost!! Burn the vines or bag the vines and remove them from your property. The soil must be exposed to reveal the cocoons.
  • Till or fluff the soil up to 2″ to expose SVB cocoons. Songbirds and poultry delight in eating the pupae (cocoons).
  • Always rotate your squash crop to another space each year.

My strategy this year includes the Blue Hubbard trap crop and yellow trap buckets. Plus, I will preemptively spray the ground stems with a mixture of vegetable oil and Dipel (Bacillus thuringiensis). I’ll keep you updated throughout the summer.

Papa

Cucumber Beetles Prefer “This” Over the Cucumber Vine!

The Spotted and Striped Cucumber Beetle wreak havoc on cucumber, melon and squash (Cucurbits). Here is another great trap crop, Amaranth.

spotted cuc beetlesstriped cuc beetle

One bite from these nefarious beetles and bacterial wilt enters the vines causing them to collapse and die. The vascular bundles (the nutrient transport system of the plant) get filled with bacteria and shut down the plant. Subsequently the plant will die. Plants with bacterial wilt must be pulled, burned or placed in a trash bag for removal. This plant material must not be composted. The first photo shows the effect of bacterial wilt. The second photo illustrates the bacteria expressed as gummy strings.

Bacterial wiltBacterial wilt1

In my experience, the best way to prevent bacterial wilt is the use of a specific trap crop. Two (2) years ago I discovered by observation cucumber beetles eating wild pigweed (amaranth). The wild pigweed was pressing against the leaves of a cucumber plant. There was no evidence of beetle infestation!! The beetles overwhelmingly preferred the wild pigweed. The same phenomenon may be seen on cultivated varieties of amaranth.

PigweedAmaranthamaranth-tricolor-aurora

Baker Creek Heirloom Seed Company has several varieties of amaranth in their inventory – http://www.rareseeds.com/store/vegetables/amaranth/ Choose one or more varieties to entice the cucumber beetles away from you cucumbers, melons and squash .

Use amaranth as a trap crop and follow these guidelines:

  • Plant amaranth next to a cucurbit crop to attract cucumber beetles as either a food source (pollen/nectar) or an egg/larval site.
  • Amaranth/wild pigweed attract cucumber beetles to the border areas, where the amaranth/wild pigweed can be consumed. Pests on the cucurbit crop will be reduced. Plant cultivated varieties or wild amaranth transplants either surrounding, adjacent, at the four corners or in containers next to the crop.
  • Exploit the cucumber beetles special appetite.
  • Intercept the cucumber beetles from the edges.

Plant cultivated varieties of amaranth or encourage wild amaranth in your garden/property (as a trap crop) three (3) weeks prior to planting summer squash, winter squash, cucumber, cantaloupe and watermelon . The amaranth may be seeded in pots for transplanting or direct seeded, prior to direct seeding squash, cucumber and melons. Amaranth grows fast enough to satisfy the cucumber beetles appetite.

Disclaimer: Please use common sense and discretion regarding the use of  wild types of amaranth (pigweed). It may be invasive in your area.

Papa

Got Squash Bugs? Use Trap Crops!

Ugh, here we go again. Those nasty squash bugs are back! I really wanted to grow zucchini and yellow crookneck. Why waste my time! I hear this over and over again.

Now, there is a solution. Trap Crops!

  • Plants that are planted next to a squash crop to attract pests as either a food source (pollen/nectar) or an egg/larval site.
  • Attract pests to the border areas, where they can be killed. Pests on the unsprayed crop will be reduced.
  • Exploiting the squash bugs special appetite.
  • Intercepting the pest from the edges.
  • Check trap crop three (3) times per week.

Plant Red Kuri squash, Blue Hubbard Squash and Buttercup squash (as a trap crop) three (3) weeks prior to planting summer squash, winter squash, cucumber, cantaloupe and watermelon. The trap crop should be seeded in pots for transplanting, prior to direct seeding squash, cucumber and melons. Monitor for squash bugs to determine if treatment is needed on the trap crop.

Plant Red Kuri or Blue Hubbard or Buttercup squash transplants either surrounding, adjacent, at the four corners or in containers next to the crop.

red kuri blue hubbard

buttercupTrap Crop illustration

Monitor for squash bugs.

squash bug eggs nymphsquash bug nymph

Squash bug adult

Spot spray the squash bugs on the trap crop with a*pyrethrin insecticide. It may be necessary to spray the entire trap crop when the population threshold is exceeded. In other words, the squash bugs have infested the entire trap crop with eggs, larvae and adults.

*Pyrethrin insecticides – Evergreen Pyrethrum Concentrate, *OMRI Listed

PyGanic® Crop Protection EC 5.0 II, *OMRI Listed

* OMRI Listed: The Organic Materials Review Institute (OMRI) is a national nonprofit organization that determines which input products are allowed for use in organic production and processing. OMRI Listed—or approved—products may be used on operations that are certified organic under the USDA National Organic Program.

Caution – You must read the label!! The label is the law!! Pyrethrins will instantly kill any insect that is sprayed. That includes beneficial insects (honey bees, bumble bees, lady bugs, parasitic wasps, etc.). Be very careful!! Remember, squash crops, cucumbers, and melons are dependent upon pollinators to produce fruit.

When you follow these steps you will enjoy a fruitful harvest. Let me know of your success!

Papa

You may purchase the above varieties of squash at Baker Creek Heirloom Seed Company by clicking on the links below.

http://www.rareseeds.com/red-kuri-squa-hokkaido-/

http://www.rareseeds.com/blue-hubbard-squash/

http://www.rareseeds.com/buttercup-squ/

Leaf Miner, huh? What’s a Leaf Miner?

Jan  My organic garden plague is leaf miners! Suggestions?

I get this picture in my mind of a small creature with a miner’s hat and a pick. In reality, they are the larvae of a fly that burrow through leaves. Usually the damage is not aesthetically pleasing. However, if left unchecked, leaf miners can cause major damage.

Here are some solutions:

  1. Monitoring – kill leaf miner larvae in the leaf if possible.
  2. Nutrition –  a healthy plant has thicker, healthier leaves. Plus, biochemically, the plant is not as appealing to the leaf miner.
  3. Floating Row Covers – creates a mechanical barrier that keeps the leaf miner fly away from the crop.
  4. Parasitic Wasp – Diglyphus isaea is a parasitic wasp that prey on the larvae of the leaf miner fly.
  5. Neem Oil – Neem Oil may break the life cycle of the leaf miner larvae to keep them from growing to maturity.

Getting rid of this pest takes diligence!

What to do about slugs and snails, naturally!

Lindsay  – Snails! I really REALLY make every effort to garden organically, but I am having an infestation of snails, and am stumped as to what to do about it.

There are many natural solutions for slugs and snails.

  1. Sanitation is key! Make sure there is no debris for them to hide. Do not plant next to a compost pile.
  2. Plant trap crops for them to eat. Marigolds, brassicas, melons, lettuce,strawberries, etc. are great attractants of slugs and snails.
  3. Plant resistant plant varieties – lavender, rosemary, sage, wormwood, impatiens, poppies, geraniums, etc.
  4. Barriers – copper strips, Diatomaceous Earth, sand, and wood ashes. Be careful with wood ashes! You could make your soil pH go sky high!
  5. Traps – stale beer in containers at ground level, melon halves turned upside down, untreated wood boards laid on top of the ground.
  6. Guinea fowl will eat them. They shouldn’t eat your crops!
  7. Encourage your Lightning Bugs – their larvae eat slugs and snails!!!
  8. Iron phosphate baits such as Sluggo® or Escar-Go®

That’s quite an arsenal!

Papa

Question: Help! What do I do for peach tree borers?

Hi, my name is Kristina . I have a question concerning my peach tree. Last summer it got infected with borers (I was told these are a type of moth??). Anyway, the tree company I was with at the time couldn’t do anything about the borers since it wasn’t until late July early August that we saw the sap coming out of my tree. So I poured nematodes on the soil around my tree and in to the holes that were sapping. I did this 3 different times 3 weeks apart while I hung moth balls in a sock on the tree too. I am being told now by a new tree company that they don’t do pesticides for borers until June, since the borers aren’t active until then. My question is, what would you do for this peach tree? Should I just wait until June or can I be doing something more to help my tree that I don’t want to lose. Thanks
Here’s what you do! Spray the trunk of the peach tree with a strong solution of Neem Oil and water (3 tablespoons to the gallon of water and a little dish soap) Spray to the point of puddling around the trunk. The Neem Oil will either out right kill the worm or interrupt the worms life cycle, which will also kill the worm. You need to spray at 14 day intervals (twice) to be effective.
You will build up the immunity of the peach tree by spraying  and drenching the tree with seaweed emulsion (i.e. Maxicrop®), at one (1) tablespoon per gallon.
-Art