Archive for the ‘Pest Control’ Category

Colorado Potato Beetles-Not just for potatoes!

Colorado Potato Beetles are back in the garden.  Here they are in all their stages.  The best way to manage these is to put on a pair of gloves, pick them off your plants and squish them.  Sorry, but these guys are resistant to just about every other method, including natural predators.  They over winter in the soil and in the field margins.  They also eat tomatoes, eggplant and pepper.  Crop rotation can help but is difficult in a Community Garden setting.  If you see them on your plants or someone else’s please eliminate them!  Thanks

Colorado Potato Beetle larvae

Colorado Potato Beetle larvae

Potato Beetle Eggs

Potato Beetle Eggs

Adult Colorado Potato Beetle

Adult Colorado Potato Beetle

Tomato News

Well here I am again with more challenging news about the gardens.  Tomato season is almost upon us.  Tomatoes are the most popular vegetable grown in our garden and very much anticipated.  That’s why it’s disappointing to see some tomato problems starting.  Just this week, my tomatoes began to exhibit Tomato Leaf Septoria.  This disease is caused by a fungus that thrives in humid, moist conditions.  The bottom leaves of the plant develop small black spots , turn yellow, and then brown.  The fungus doesn’t get on the tomatoes themselves but does weaken the plant and shorten it’s production period.  Removing the yellow, diseased leaves and branches is the first thing to do.  These should not be put into the compost pile but should removed from the garden area.   When watering, try to avoid watering the leaves of the plant and focus the water around the base of the tomato plant.  The idea is to improve air circulation and discourage the moist conditions that promote the fungus.  A copper spray can be used on the healthy foliage to help protect it from the fungus.

And, while I was cleaning the diseased leaves from my tomatoes, I was lucky enough to find the first tomato hornworm on my tomato plants .  The one I found was still on the small side and I couldn’t find others but I am sure they are there.  They are like mice, if you see one, that means you probably have dozens.  I will remind gardeners of my quick and easy way to deal with them:  a pair of scissors cuts them in half .  It’s  faster than trying to pull them off since they have strong grasping feet and pulling on them usually means they end up exploding in your hand –not pleasant.  However, if you see one carting around a bunch of grains of rice, leave it alone.  Those are the eggs of a parasitic wasp whose larvae feed on  the hornworm and kill it.  We want to encourage  those wasps.

By the way, I did harvest my first yellow Garden Peach tomato and a handful of Sungold cherry tomatoes.  Happy Gardening

septoria leaf spot

septoria leaf spot

Septoria leaf spot

Septoria leaf spot

tomato hornworm with parasitic wasp eggs

tomato hornworm with parasitic wasp eggs

Tomato hornworm larvae and adult moth

Tomato hornworm larvae and adult moth

Salsa? Yes! Mexican Bean Beetles ? No!

I’m a fan of multiculturalism, diversity, ethnic cuisine, but my enthusiasm pales when it comes to Mexican Bean Beetles.  This morning I was reveling in picking my first crop of green beans when I came face to face with a Mexican Bean Beetle.  Darn!  Here is a great picture of their life cycle and, yes,as adults,  they do look a lot like ladybugs which is probably how they escape our wrath.  I’m providing some information about organic controls.

Consider these natural controls for Mexican bean beetles, listed in seasonal order:

Handpick adults and larvae whenever you see them. Squash egg clusters with your fingers. Once you see a few larvae, handpick daily to achieve good early season control.
Interplant petunias with beans. Another popular companion planting approach involves growing rows of beans between rows of potatoes.
Install floating row covers over bush beans in early summer, after the young seedlings have been weeded. Open the covers weekly to check for the presence of any adults or larvae, and remove them. Row covers work beautifully to prevent this bean pest, but lucky individuals occasionally emerge and prosper beneath them.

If you have a home chicken flock, have the birds work over pulled bean plants before they are composted.
In large plantings of more than a quarter acre, these organic interventions may be worth their substantial cost:

Spray with a product based on the fungus Beauvaria bassiana (such as Mycotrol) as soon as Mexican bean beetle larvae are seen. When the first generation of larvae becomes infected with this fungus, sufficient spores are usually present to infect later generations.
Release an imported, commercially-reared parasitic wasp called Pediobus foveolatus after Mexican bean beetle larvae have appeared. State support may be available to growers in New Jersey and Maryland.

More Advice on Organic Mexican Bean Beetle Control

Keep a close watch on your growing beans in spring, and do not allow the first generation of Mexican bean beetles to triple itself by the time your beans grow into big, robust plants. Do all you can to provide food and habitat for beneficial wasps, flies, ladybeetles, and predatory stink bugs. Scout for eggs if adults are seen, using a small hand-held mirror to get a good look at leaf undersides.

Planting plenty of flowers that attract beneficial insects is a sound strategy, along with maintaining seldom-disturbed islands that provide habitat for ground beetles and other beneficials.

More information on organic Mexican bean beetle control is available from the University of Massachusetts, Cornell University and Florida State University.

Read more:

life_cycle : Mexican Bean Beetle

Organic Pest Spray

This recipe for an organic pest spray comes from Strawbery Banke.  We are suggesting it for use in the Community Garden and will welcome feedback on it’s effectiveness.  Note that this spray will only work if it is applied frequently and reapplied after rain or heavy morning dew.

Cornell Mix
This is the organic pesticide mix that we use on our plants at Strawbery Banke. The ingredients are inexpensive and the uses are versatile. Works great for a wide range of insect pests and mildews.

You will need:
Spray bottle
1 gallon jug
1 TBS Dr. Bronner’s liquid concentrate soap (or other all-natural liquid soap without phosphates)
1 TBS olive oil
1 TBS baking soda
Warm water

Put small amount of warm water in the bottom of the jug. Add soap, olive oil and baking soda. Swirl ingredients to blend them. Fill the rest of the jug with warm water and then put the cap on. Shake thoroughly. Dispense into spray bottle.

When applying to plants, make sure to get the undersides of leaves, tight crevices and tender new growth. Keep shaking mixture to keep ingredients well incorporated (oil will try to separate). Apply once a week for prevention and more often for an active problem.

Pest ID. and Elimination

Dear Gardeners,  Our gardens are all looking beautiful and are about to burst with fresh food.  Just when we are starting to count our squash, tomatoes, beans etc.  insect pests also arrive to enjoy the bounty.  Here are several that I have seen in the garden.

Squash Beetles:  There are several varieties of squash beetle.  The most common is the gray beetle shown below.  These can easily become swarms that destroy your squash plants if not controlled.  The easiest way to control them is to search your leaves for the eggs.  They can appear on the tops or undersides of the leaves  You will need to examine each leaf because they can be lurking anywhere.  Using duct tape(available in the shed)  wrapped around your hand sticky side up,  pat the eggs to remove them from the leaves.  You will probably need to make several loops of duct tape to remove them all.  Dispose of the tape at home and not in the trash cans at Wagon Hill.  The gray larvae have wings and can fly everywhere.  If you see them. you can try to squish them but a better method would be to get a Safer insecticidal spray to use.   Destroying the adults is harder because they do not squish so easily.  If you bring a plastic bottle with a narrow opening and a lid you can pick them up and drop them in the bottle.  Put the lid on and throw away at home.   You will need to check your plants regularly because they keep reappearing all summer long.


Adult Squash Beetle

Adult Squash Beetle


Squash Beetle Larvae

Squash Beetle Larvae


Squash Beetle Eggs

Squash Beetle Eggs









This is another type of squash beetle I have seen.  They are not as numerous as the gray ones but just as destructive.  Treat them in the same way,  destroy any eggs you find on leaves and kill larvae and adults.

Squash Beetle Larvae

Squash Beetle Larvae

Squash Beetle

Squash Beetle









Another insect that we have in abundance, right now is the Colorado Potato Beetle.   Again, the best method is to destroy any eggs you see in yellow clusters on the leaves.  The larvae are easily squished but I would wear gloves since squishing them bare handed is pretty gross .  I have done it in desperation and know from experience.  The adults can be picked off and dropped into a bottle.

I would encourage all gardeners to “take matters into your own hands”  whenever you see any of these creatures on your plants or your neighbors and destroy them.  This is something we all can do towards honoring our 4 hour work commitment.  Keeping these guys in check is of great benefit to everyone.

Finally, a reminder to check your garden at least once a week for pests and, more importantly, for food that is ready to harvest.  With the rain and sun we have been getting,  things are growing fast and you may be surprised to find your plants producing very quickly now.   You want to be sure to reap the benefit of  your labors and harvest your food at it’s peak.  Baseball bat zucchini is not very tasty.

Potato Beetle Eggs

Potato Beetle Eggs

Colorado Potato Beetle larvae

Colorado Potato Beetle larvae

Adult Colorado Potato Beetle

Adult Colorado Potato Beetle

Notes From Ellen: Pest Control

Out at the garden today, I saw lots of cucumber beetles and my first squash beetle!  UgH!

I used a Tomato Vegetable Spray that has pyrethrum, an organic pesticide.  It seemed to knock the beetles down.  I sprayed and weeded and came back,–no beetles.  However, I will have to keep spraying.
If you do not have any bugs on your squash and cucumbers yet, you could try covering them with a row cover called “Remay”.  You will notice that many gardeners have this white filmy fabric over their plants.  You can buy it by the roll or in a package at Wentworth Greenhouse in Rollinsford.  My squash plants that were covered with Remay did not have bugs.  You have to remove the Remay once the plants get large enough to start vining out.  The Remay does protect young seedlings from cucumber beetles, cabbage butterflies, and squash vine borer moths.
The good news is that I saw a number of lady bugs–always our friends– and there are a number of papery praying mantis egg cases in the garden.  The mantis is an excellent predator.  There are many wasps that have useful phases in their life cycles that help to rid the garden of pests. One type lays eggs on the tomato hornworm caterpillar.  When the larvae hatch they devour the caterpillar!   I love to let the bugs duke it out if possible.
See you in the garden.  Ellen

Cucumber Beetles

Thanks to those of you who came out to help on Saturday’s work day.  The gardens look beautiful and food is really starting to grow now that is finally warm.

UnknownUnfortunately that also means that pests are beginning to find us too.  The cucumber beetle has appeared in abundance.  Here is some information about these pests.  Be aware that cucumber beetles don’t just eat cucumbers. They eat 270 different plants and flowers.  Below, please find some information about controlling them.
As you go about caring for your plants, be sure to check the undersides of leaves for eggs and larvae and let me know about any pests you find so I can alert other gardeners. You can even send me pictures that you take with your cell phone if you can’t identify the creatures.  In a community garden with so many of us growing the same things, pests can become “epidemic” very quickly.   Working together is our best chance of keeping these pests under control.
Happy Gardening!  Ellen

Predators: Tachnid flies, soldier beetles, parasitic nematodes and braconid wasps. Lacewings and ladybugs eat the eggs.

Repellent plants: Broccoli, calendula, catnip, goldenrod, nasturtiums, radish, rue and tansy. If you want to try marigolds to repel them use the more pungent varieties like African, French or Mexican marigolds. The more common marigolds may actually attract them, therefore could be used as a trap crop.

Control Methods:

  • Use a portable vacuum to get the adults in the early evening. Put them right into a plastic bag, seal it and dispose of them.
  • Try placing cuttings of the tansy plant as a mulch in-between rows in the garden.
  • Spread any type of onion skins on the soil around the planted areas.
  • Consider building a bat habitat: Bats are predators of a wide range of pest insects, including cucumber beetles.
  • Make a trench 3″ deep by 3″  wide filling it with wood ashes. Moisten it so it won’t blow away and don’t let it get on the plants. Ashes can be toxic to plant foliage!
  • A deep mulch of straw helps by keeping the adults from walking plant to plant. Heavy mulching can deter cucumber beetles from laying eggs in the ground near plant stems and may hinder feeding by larvae migrating to fruits. This cultural control method, however, does not protect the leaves against attack from adult insects. Injury to fruit by tunneling of larvae is dependent on very moist soil as fruits ripen. Limiting irrigation at this time can minimize damage
  • Plant white varieties of radishes or rattail radishes with your cucumber plants to repel the beetles. Rattail radish roots are not edible but the seed pods are!
  • Mix a spray of 1 ounce wood ashes, 1 ounce hydrated lime and 1 gallon water. Spray upper and lower leaf surfaces. Hydrated lime is a powdered substance. Or use a spray of hot peppers, water and garlic.
  • Trellising plants can make leaves less accessible to insect larvae and may decrease egg-laying. Like mulching, trellising does not protect plants against attack by adult insects
  • Plant radish seeds right in the hills with the cucumber plants.
  • Floating row covers are an effective control method during the early season of plant growth. They prevent insect attack by forming a barrier between insects and plants. Row covers need to be removed during the late vegetative stage, at the onset of flowering, to allow for bee pollination. Once floating row covers are removed, other control measures such as treatments with botanical pesticides should be employed.
  • To fool cuke beetles: flatten a square of aluminum foil around the base of plants to bounce light on the undersides of leaves. This also helps the plants in giving them more light.
  • Plant any type of beans with cucumber.
  • Cultivate in the fall to expose the eggs.
  • If the infestation is beyond control use either of the botanical poisons: pyrethrum or rotenone. You want to hit the adults with these when you observe them feeding on pollen in flowers.
  • Sticky Traps: For the home gardener and small scale growers these can be an effective monitoring tool and a control! Cut some plywood board into rectangles 8 inches by 10 inches. Cardboard could also be used. Paint with yellow paint and coat with Tanglefoot or some other adhesive. Now what you want to do is to bait these traps specifically to trap cuke beetles. You can use pieces of cotton wicks stuck to the boards that have been soaked in a Eugenol based oil which is what attracts the female beetles. 2 types of oils that contain 60 to 90 percent eugenol are allspice oil and clove oil. Squash blossoms contain indole which are very attractive to the adults. If you can spare some you might mash them up and stick them to your trap. Stake your traps vertically at ground level or no more than 12 inches above. As the traps fill up you can scrape and recoat them until they become unusable.
  • Nematodes: Hexamermis spp. parasitizes the adults. Studies have indicated up to 90%  of a population of cuke beetles being infected by the nematodes. Apply beneficial nematodes to kill the adults in mulch, seed furrows and around plant roots.
  • Neem Oil: Neem oil, which can act as an ovicide, can be used as a soil drench to treat eggs and larvae. It does seem to help with control of the adults as a repellant and antifeedant. Further tests must be done using Neem but it does look promising.

Growing Sweetpotatoes in N.H.

Written by UNH Extension Specialist Becky Sideman (, 603-862-3203). Updated June 2013.

Sweetpotato (Ipomoea batatas) is a member of the morning glory (Convolvulaceae) family. The sweetpotato is not related to the Irish potato, which belongs to the nightshade (Solanaceae) family. Unlike potatoes, which are tubers, sweetpotatoes are roots.

Growth Requirements

To produce a crop, the sweetpotato requires 90-120 frost-free days. The plants and roots are very sensitive to chilling. They grow best if the soil temperature is above 65F before planting. Sweetpotatoes prefer well-drained loam soils that are not too fertile. Over-fertilization causes vigorous leaf growth and long, skinny roots. If grown in heavy clay soils, roots can be small or misshapen, and will be hard to dig. A soil test will identify any major nutrient deficiencies and recommend how to correct them.

Starting Materials

Sweetpotatoes are started from ‘slips’, or plants, rather than from pieces of roots. Slips can be purchased from many seed companies or other plant suppliers. While you can start your own slips, roots from a grocery store are not usually identified by variety, so you don’t know what you are starting with.

To produce your own slips: Place sweetpotato roots on their sides in trays of soil 6-8 weeks before you want to transplant them outside. Cover the roots with 2 inches of moist sand and keep the soil in the trays between 75-80 degrees F. When the sprouts are 4-6 inches long, remove them with a twisting tug. The root will continue to produce more sprouts. Sprouts can be planted directly in well-prepared ground, or you can place them in a jar of water for a few days to produce a rooted slip and/or to delay planting.

If you purchase slips, you will have to specify the ship date. In Durham, soil temperatures under black plastic mulch are typically 65F by June 1. If your site is cooler or if you are not using plastic mulch, you may want to delay this date by 1-2 weeks.

Transplanting conditions are important for success. If poorly rooted slips are planted in sunny, hot conditions, a large number of slips may dessicate and die before roots can establish. It’s best to wait until overcast conditions, and to make sure to water slips in immediately after planting. If slips arrive long before you are able to plant them, place the entire bundle of slips in a pot and pack potting mix loosely around the bundle, and water as any other plant. This ‘heeling in’ can successfully hold slips for a week or more prior to planting.


Sweetpotatoes respond well to ground-warming black plastic mulch. The sheet of plastic is laid tight against the soil, and slips are planted into holes cut in the plastic. It is possible to produce good yields without plastic mulch, but the warming mulch extends the growing season by a few weeks, which can increase yields dramatically.



Typical pests of potato (Colorado potato beetle, potato leafhopper, etc.) do not bother sweetpoatoes. However, they do have some pests:

  • Deer love sweetpotato foliage, and will browse it to the ground. While this won’t kill the plants, it will reduce yields significantly. Since there is plenty of other food for deer in midsummer, a lightweight electric fence may successfully keep the deer at bay.
  • Voles also love sweetpotatoes. Some NH farmers have reported that voles have eaten their entire harvest. Keeping weed populations under control and keeping the area around the planting mowed and/or tilled can help reduce vole damage.
  • Scurf is a soilborne fungal disease. It discolors the skin of the root, so that the root is covered with rough black patches, but does not harm the root. Some varieties are more susceptible than others.
  • Wireworms can be an issue for sweetpotatoes grown in fields that were sod (or that were weedy with perennial grasses) in the previous year.

Harvesting and Storing


Sweetpotatoes should be dug as late as possible in the fall, but before a hard freeze. The vines can tolerate a light frost. It can be helpful to mow and remove the vines before digging, to provide easier access to the roots. After digging, sweetpotatoes should be ‘cured’ by placing them in a warm (80-85F) place for 4-7 days. This heals any wounds on their skins, and increases their storage life. Sweetpotatoes should be stored in moderately warm (55-60F) and humid conditions. The roots are easily damaged by temperatures lower than 50F.

For best eating quality, it is important to wait a few weeks before eating roots once they have been dug. Our research has shown that percent soluble solids (primarily sugars) can increase over 4% in three weeks, and then starts to taper off once most of the starches have converted to sugar.



Sweetpotato varieties perform very differently, so it’s important to test performance in your situation. Varieties that are well adapted to New England conditions include the following:

Beauregard –Orange flesh and copper skin, good flavor. Early, produces high yields. Highly recommended.

Covington – Orange flesh and copper skin, excellent flavor. More uniform shape, higher marketable yields and better flavor than Beauregard. Highly recommended.

Georgia Jet – Orange flesh and rose colored skin. Very susceptible to cracking and storage losses. High yield potential and good flavor. Cracking may depend on moisture level in soil. Better for home gardens than for commercial use.

Japanese –White flesh with purple skin. Unique smooth texture, good flavor. Non-uniform size and shape.

O’Henry and White Yam –  White/cream-colored flesh and skin. These are both high yielding, with good flavor.

Carolina Ruby – Deep orange flesh, garnet-colored skin. Skin has unusual rough texture. Moderate yields, average flavor.

Vardaman – Light orange flesh and skin. Excellent flavor. Produces small slender roots, and low yields.


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The Pests Have Arrived!

How do those bugs and blights find my garden so quickly? I am always amazed! As I learned this week at Dr. Cheryl Smith’s excellent presentation, they over winter in and around the gardens. The know a good thing and stick around. Right now we are already seeing evidence of the potato beetle. A mature bug was squashed just the other day. And speaking of “squash” the squash beetle isn’t far behind. I’ve posted pictures of these bugs in their various life stages so you can recognize them. Our main defense is prevention. This means being vigilant about checking your plants regularly and taking action at the first sign of something amiss. On our resources page you will find links to lots of helpful information. But now is the time to start looking for those egg clusters on the backs of leaves. If you find them, rub them off. Or, if you do not want to use your fingers, we will be supplying a roll of duct tape in the shed for the purpose of egg removal. Make a loop of duct tape, sticky side out and slide your hand into it. Then use it to pat the eggs until they all stick to the tape. Repeat as often as necessary. Make sure to seal the tape in a bag and dispose of it in your trash at home. If you see something in someone else’s bed, note the bed number and let me know so that I can alert them. Let’s help each other enjoy the fruits of our labors.