The Yellow Farmhouse Garden

August 30, 2019

Striped cucumber beetles can devastate your crop

The first striped cucumber beetles of the season have finally showed up in my garden. These bright and happily colored pests cause a lot of damage in the garden. Although cucumbers are their preferred food, melons are also attacked was well as squash and pumpkin to a lesser degree. At this time of the year, these are actually the second generation descended from those that were around earlier in the spring. I didn’t see those from the first generation in my garden but they must have been around in the neighborhood.

Cucumber beetles have a distinctive yellow color with black stripes.

Cucumber beetles have a distinctive yellow color with black stripes.

Typical cucumber beetle feeding damage.

Typical cucumber beetle feeding damage.

Adult beetles are a triple threat to cucumbers. First, the physical act of feeding by chewing holes in leaves reduces the leaf area stunting plant growth.

Secondly, they reduce the number of actual cucumbers by destroying flowers as they feed on them. Fewer flowers equals fewer cucumbers.

Cucumber beetles will eat  flowers as well as leaves.

Cucumber beetles will eat flowers as well as leaves.

The third threat is the most damaging of all. In their gut is a bacteria that causes bacterial wilt, a very serious disease that can destroy a majority of a crop. As the beetles feed randomly over the surface of the leaves, eventually they will have to defecate. The feces contains large amounts of bacteria that will infect the plant if it is deposited over a chewed spot.

As you probably can guess from its name, bacterial wilt causes vines to suddenly wilt. Early on during the infection, vines will appear to recover somewhat overnight only to wilt again the next day as the day progress. The vines will eventually die in about seven to ten days — there is no cure. Remove any infected vines and compost them or discard them away from the garden.

Symptom of bacterial wilt on cucumbers.

Symptom of bacterial wilt on cucumbers.

One single beetle is enough to infect an entire plant so it’s important to kill the beetles as soon as you see them. There are conventional and organic insecticide sprays on the market that do a good job controlling them.

Plant breeders have developed cucumber varieties that are less attractive to beetles than regular varieties. Organic farmers will grow the one of the new varieties as their main crop. At the same time, they plant a more attractive variety in different spot to lure the beetles away from the main crop eliminating the need to spray the main crop.

If all that damage is not enough, as a bonus, the beetles will feed on the actual cucumbers themselves leaving behind feeding marks that disfigure the fruit.

Another species, the spotted cucumber beetle, also can show up. They are the same size and shape as the striped beetles but have black spots instead of stripes. They cause the same kind of damage and need to be controlled too.

Bob

August 15, 2019

Michigan monarch butterflies and milkweeds up north

We’ve been spending time in northeast Michigan on and off for the past month or so. In one particular location, I noticed more Monarch butterflies this year than in the past.

A couple of weeks ago there were at least a dozen Monarch adult females frantically flying around from plant to plant laying eggs on a colony of milkweed plants. That lasted for a couple of days and was still going on when we left for home.

We returned earlier this week expecting to find caterpillars all over the place. The plants were still there but there were no caterpillars to be found anywhere. The only difference was the plants had bloomed and the blossoms were quickly fading.

These are a different species of milkweed than we have at home. The purple flowers with their distinctive scent along with a purple mid-vein on the leaves, plus other traits, told us these were purple milkweed, Asclepias purpurascens. At our home in southeastern Michigan we have mostly common milkweed, Asclepias syriaca.

 There are several species of milkweed. This is purple milkweed.

There are several species of milkweed. This is purple milkweed.

I’m not sure why no caterpillars developed on the purple milkweed plants. It could be that predators ate the eggs before they hatched or ate the small caterpillars just as they emerged from their eggs.

On the other hand, this past weekend in the Caseville area, our daughter Robin and her cousins saw tons of caterpillars on milkweeds. Each and every plant, even the yellowing ones, had at least two caterpillars, others had even more. They didn’t know what species of milkweed those were since the plants hadn’t started blossoming yet. Adult females were quite busy laying eggs there too.

With that many caterpillars you expect to see evidence of predators and they did. While admiring a caterpillar up close, out of nowhere a predatory wasp zoomed in and dive bombed it. The caterpillar fell from the plant and was writhing wildly on the ground. When the spasming ceased, the hikers returned him to his roost on the milkweed. The hikers didn’t know it at the time, but the caterpillar was already doomed. The wasp had laid its eggs inside the caterpillar’s body making a nursery for a new generation of wasps.

We did eventually find a caterpillar on the purple milkweeds in the northeast location. We found it in a most unlikely spot. While we were hiking through a dense, shady cedar swamp with ferns, mushrooms, and jack-in-the-pulpits we came across a clearing where some trees were knocked over during a storm.

forest floor up north

In the middle of that sunny clearing was a single purple milkweed plant that had one lonely monarch caterpillar that was nearly full grown.

An airborne milkweed seed landed in the middle of the woods and took root. Later a female butterfly found it and laid an egg.

An airborne milkweed seed landed in the middle of the woods and took root. Later a female butterfly found it and laid an egg.

 Deep in this seemingly inhospitable environment, it was no place for a butterfly. It’s a wonder how the Mother Monarch found her way there at all.

 Bob

July 27, 2019

Remove fallen fruit from your orchard

What’s worse than finding a worm in your apple? A: Finding half a worm.

Modern pesticides and strict inspection policies have made finding a codling moth larva, or worm in an apple from a supermarket’s produce department a pretty rare thing for most consumers. Even though kids nowadays have never had that experience, the friendly worm in an apple still is subject of children’s books and cartoons.

A codling moth larva crawling out of an apple -- the proverbial worm in the apple.

A codling moth larva crawling out of an apple — the proverbial worm in the apple.

Most backyard fruit growers on the other hand, have had direct experience with codling moth larvae. It’s one of the most common insect pests attacking apples and pears and if you let down your guard they will find your fruit and make a home in it.

Codling moths have a lifecycle similar to other moths. First, the adult female lays her eggs on the surface of an apple. Then the eggs hatch and the tiny larvae burrow into the fruit eating their way to the core. When fully grown, the larvae emerge from the fruit and find a protected area where they spin a cocoon and pupate. Early in the season they will emerge as new moths and lay more eggs.

Those present at the end of the season will spin a cocoon but will not pupate. Instead they overwinter as larvae inside their cocoon and pupate the following spring.

A regular spray schedule will keep these pests at bay but not everyone wants to use chemicals on their produce. In fact a major reason people have for growing their own fruit is to eliminate or reduce the amount of chemicals they may be exposed to. Sometimes a spray or two can missed, due to weather or other reasons, allowing the moths to gain a foothold.

Like most things in life, ignoring the problem will not make it go away. If you don’t want to spray, you’ll have to do some other things to reduce the number of worms.

The first is to pick any damaged fruit on the tree to keep the larva inside from completing their life cycle. Also pick up any fruit that falls. Codling moths are just as happy to live inside a fallen apple as one hanging on the tree. Dispose of these apples in a way that the larva are destroyed. I give mine to our chickens, they love those wormy apples. For them, the worm is a special treat inside!

Composting is usually not a good option for disposal because most backyard compost piles don’t get hot enough to destroy codling moth larva. Municipal composting on the other hand has no problem with them. So bag them up for city compost or put them in with your regular trash.

Codling moth females prefer to lay their eggs on the most protected spot on a fruit. This often is on the spot where two apples are touching each other. Removing one of the apples eliminates the “sweet spot” that egg laying females are looking for. It’s one of the reasons why you should thin fruit as your crop begins to develop.

While getting rid of infested fruit helps tremendously, it won’t completely eliminate codling moths. The can fly fairly long distances and may fly to your trees from surrounding areas where fruit is left to fall and codling moths emerge.

Other fruit pest such as apple maggot, oriental fruit moth and plum curculio also can be reduced by disposing of fallen fruit.

Bob

 

July 19, 2019

Warning! Insect invasion. Four vegetable garden insect pests in mid-July

Insect pests have begun to show up in my garden this week. It seems like it’s early for them, but that’s only because the garden plants are small for this time of the year due to our late start. It is the middle of July after all so I would expect some insect problems.

The first insect I spotted in the garden were cabbage butterflies. They are those white butterflies that flutter around the garden. They feed on plants in the cabbage family, including cabbage, broccoli, cauliflower, and other related plants. Watch them closely when they’re in your garden. Every time a female butterfly briefly touches down, she lays a single tiny egg. Over time she will lay a lot. Of course the butterfly itself is harmless, it’s her larval offspring that are so destructive. Many of the eggs and small larvae will be eaten by beneficial insects before they even have a chance to do any damage but there will always be plenty left over to munch on your plants.

 

Cabbage butterfly eggs can be found anywhere on the plant.

Cabbage butterfly eggs can be found anywhere on the plant.

I suggest you take steps now to nip this problem in the bud. A spray of the biological pesticide Bt right now, will easily kill these pests while they’re in their most vulnerable stage of growth.

The next problem insect I spotted was a female squash bug laying her eggs on a squash vine. She’ll lay her eggs on any pumpkin, squash or related plant. Usually you’ll find the eggs on the underside of a leaf but this one was laying her eggs on the upper surface.

     Here’s an adult female squash bug laying eggs.They are hard to kill. Try knocking them into a pail of soapy water.

Here’s an adult female squash bug laying eggs.They are hard to kill. Try knocking them into a pail of soapy water.

One way to reduce their numbers is to squish the egg masses before they hatch. Later on, if the bug population is high and the vines begin to wilt, you may have to resort to an organic or conventional insecticide. They are very destructive to squash vines and can leave you with next to nothing to harvest if left unchecked.

The third insects making their appearance in my garden this week are tomato hornworms. These are the larval stage of the fascinating sphinx moth. Farmers rarely take notice of tomato hornworms because they don’t usually occur in high enough concentration to make it economical to apply insecticide for them. If the worm count goes above one for every two plants, then farmers will think about doing something about them.

In a typical tomato field there are thousands of plants but in a home garden there may be only a few, making tomato worms a real threat to a gardeners harvest.

Even if you look closely you probably will not find any hornworms on your plants because they are so well camouflaged. Plus, right now, since they are just getting started, they are very tiny. The ones I spotted were about a quarter of an inch long. At this early stage, they really don’t harm the plant much.

     I found four of these little guys on my tomato plant. Even at this stage you can see their distinctive horn. Cute huh?

I found four of these little guys on my tomato plant. Even at this stage you can see their distinctive horn. Cute huh?

However, when they grow to their full size — about three inches long — they can decimate a tomato plant by eating all of the leaves and will feed on tomato fruit to boot.

I’m worried about my tomatoes being hammered by hornworms this season. Because I planted them late, they are only about half the size for mid-July. That means there are far fewer tomato leaves per plant for the hornworms to feed on making my small plants more vulnerable. So I’ll be watching them very closely the next few weeks.

The last pest I found were Colorado potato beetles on my potato plants. They must have arrived during the weekend because they were eating my potato plants and getting fat. I killed a couple dozen that were feeding on one plant.

An adult Colorado potato beetle, easily identified by its stripes

An adult Colorado potato beetle, easily identified by its stripes

     Colorado potato beetle larva. Both larvae and adults can be controlled by knocking them off the plant into a pail of soapy water.

Colorado potato beetle larva. Both larvae and adults can be controlled by knocking them off the plant into a pail of soapy water.

Adult beetles and larvae are in my garden now. The female adults are busy laying eggs and the larvae are busy eating. Crush the orange eggs whenever you find them.

I suggest you scout your garden now and take steps to control these pests before they have a chance to cause real damage.

Bob

February 8, 2019

Selecting plants for butterflies

It’s been a long time coming, but more and gardeners are finally becoming interested in growing butterfly gardens. Eleven years ago, almost to the day,  I posted a blog  trying to encourage folks grow more plants that attract and sustain butterflies. I figure it’s time to revisit that subject again.

Seed catalogs are arriving everyday in the mail now, both in my email inbox and in my outside mailbox. Almost all of them offer seeds for butterfly attracting plants.

This blog is about plants that have flowers that the adult butterflies readily come to for nectar. An even more ambitious butterfly garden is one that includes plants that the larvae of butterflies need to eat, but that will have to be another blog.

Butterflies are looking for flowers that have lots of nectar and a good landing platform for them to cling to. They also prefer small tubular flowers that are especially adapted to the butterflies’ proboscis, their specially shaped tongue that works like a straw. These tubular flowers cannot be too long or the butterfly cannot reach all the way down to the nectar which is usually at the base of the petals.

There are so many plants from to choose from that it can get frustrating. To help you get started , here’s a of list of the more common plants, in no particular order, that attract butterflies:

Thyme; Valerian; Heliotrope; Asclepias incarnata (common name-Red Swallowwort); PhloxAllysum;Verbena, all the different kinds of verbena are good — Verbena bonariensis is very easy to grow here in Michigan; Thistle; Scabiosa; Columbine; Chrysanthemum; Herbs, many of them have good nectar flowers; Milkweed, attracts at least 17 different kinds of butterflies; Queen Anne’s Lace; Liatris, common name Gayfeather; Gaillardia; Butterfly Bush (of course); Echinacea purpurea, common name Purple Coneflower; Violets; Lilac; Yarrow; Rudbeckia hirta, common name Black Eyed Susan; Monarda, common name Bee Balm; Lupine; Marigold; Daisy; and Lavender.

Zinnias flowers are attractive to butterflies, plus they  keep blooming the entire growing season.

Zinnias flowers are attractive to butterflies, plus they keep blooming the entire growing season.

Other things you will want to consider when you plant your garden is: 1) have a sunny site that is sheltered from the wind, butterflies get tossed around by a breeze fairly easily 2) provide a place for them to “puddle”. Have you ever noticed butterflies hanging around mud puddles? They are slurping up much needed dissolved minerals, sort of like a food supplement, that are not found in nectar. A shallow container of water containing sand and rocks allows butteries to land and puddle. Actually, even just a simple mud puddle is fine, just replenish it as it gets dry.

Bob

 

 

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