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 22, 2019

Purslane in the garden, friend or foe?

Returning to one of my gardens after being away for a week, I noticed there were a lot of weeds that had spread over the garden. I thoroughly hoed the garden before I went away the previous week but I didn’t have time to rake up the cut and dislodged weed stalks. Usually the hot August sun is enough to dry them up and finish them off. There were a couple of good thunderstorms that rolled through during my absence that dropped enough rain to keep the weed stalks moist.

Most of the weeds that got cut off by hoeing did die despite the rain. One notable exception was the purslane. It was present in fairly high numbers and the plants were small, but they did get hoed.

Purslane has succulent leaves that resist drought and desiccation. Small pieces of stems can take root and grow into full size plants. It also has a central taproot that, if cut but not removed, can rapidly regrow.

These cut pieces of purslane will root themselves if not removed from the garden.

These cut pieces of purslane will root themselves if not removed from the garden.

In one area the purslane formed a nice mat devoid of other weeds. In that spot the other weeds died from the hoeing while the purslane was able to reestablish itself taking up all available growing space.

Purslane does not compete very much with most vegetable crops for water and nutrients. There has been some thought by researchers about the possibility of using purslane as an alternative to herbicides for some food crops. Because it is low growing and can form a dense mat, it is able to reduce the number of more aggressive weeds from getting started. I’m not inclined to experiment with that this year but I may devote a small plot next year to a purslane companion plant trial. Let me know in the comments if that would be something you’d like to see.

Very few other weeds were growing in this dense mat of purslane.

Very few other weeds were growing in this dense mat of purslane.

Purslane is considered a wholesome food in many cultures around the world. It was brought to this continent by Europeans over 500 years ago, back when they didn’t know about introducing alien plant species to a new area. As a result, you can find it in most farm fields, gardens and landscapes.

Cultivated varieties have been developed that grow upright and have much larger leaves. Seeds for those are available at many seed sellers. I’ve even seen seeds of the wild variety for sale on eBay and other sites. I don’t think that would be a very good idea since each purslane plant can produce hundreds of tiny seeds that can eventually become a problem. I may be willing to grow a cultivated variety just to try it out but not a wild plant that has the potential to turn into a weed in my garden.

Purslane leaves and stems are edible and quite tasty,

Purslane leaves and stems are edible and quite tasty,

Lately I have started eating my wild purslane more regularly. In the past I’d nibble on a stem or two just for fun but now I’m including it in my diet more and more, especially since my lettuce is long gone. It is very nutritious, as are many other wild edibles. Along with high concentrations of the more common nutrients, very high amounts of omega-3 fatty acids are also present – five times more than spinach.

My favorite way to eat purslane is to add a few sprigs to my salad or put it in a sandwich. Both the leaves and stems are edible.

About three and a half ounces of fresh purslane constitutes one serving.

 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 31, 2019

Agricultural paper mulch is performing well so far

In a previous blog post I discussed how I was experimenting with agricultural paper as a weed barrier to control weeds in my garden.

Agricultural paper mulch is engineered to slowly break down over the course of a growing season. Then when the growing season is over, whatever is left of it gets tilled into your garden soil. That saves lots of labor and keeps debris out of the landfill. Plus, it adds a bit of organic matter to the topsoil.

Since it is paper, no nasty chemicals are released into the environment as garden soil microorganisms break it down. As a result, it is suitable for organic growing unlike “biodegradable plastic” that does breakdown into unwanted compounds.

We’re well into the growing season and it’s been about five weeks since I installed the agricultural paper in my garden. It’s protecting a row of tomatoes about twenty feet long. I thought it would be a good time to see how well it’s holding up.

Areas of paper are completely gone along the edges.

Areas of paper are completely gone along the edges.

The decomposition process is beginning to be noticeable. You can see it as you walk by that the color is fading somewhat and that it’s coming apart here and there. It is however, still doing a great job keeping weeds from growing. The only places where weeds are evident are in the openings I made for planting and in spots where there was a tear or other damage.

The weakest spots are those narrow areas where the paper meets the soil surface where the edges are buried. In many places the paper is missing.

Paper is missing where it touched a lump of soil.

Paper is missing where it touched a lump of soil.

This is where the most biological activity is happening. I am not sure if is due to bacterial decomposition or from soil creatures like pill bugs chewing on it. It may be a combination of the two as the paper weakens making it more appealing to pill bugs or other arthropods.

So far, even with all the rain we’ve had, the paper is holding up quite well. I’ll continue monitoring the mulch and will keep you updated as the season progresses.

 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

 

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