Monthly Archives: May 2014

Asparagus Beetles

The vegetable garden has a small bed of asparagus that’s been growing for 20+ years. Asparagus is a perennial vegetable that takes a little time to get established but once it’s growing, it’ll last for decades.

I’ve never had any problems with the asparagus aside from keeping the rabbits from eating the young stalks as they emerge from the ground. However this year I noticed something I’d never seen before. On some of the spears there were little black rods that were attached in vertical rows.

I wasn’t sure what those black rods were. I initially thought that they might be some kind of insect frass (the entomologist’s term for insect droppings) but the orderly way that they were attached to the spears made me doubt that I was seeing frass. Insect eggs seemed like a more likely identification.

Asparagus Beetle Eggs

Asparagus Beetle Eggs

One quick Google search identified these mysterious rods: they’re the eggs of the asparagus beetle (Crioceris asparagi). The adult beetle overwinters in debris near or in an asparagus bed and then emerges in the spring. The beetles feed on the emerging spears and lay their eggs on the spears in straight vertical rows. The cycle from egg to adult is a quick one: the eggs hatch in about a week; the larvae feed on the spears and ferns of asparagus, going through four instars in about eight days; the larvae then pupate in the soil and emerge as adults in another week.

In reading about this beetle, I learned that it’s most active in the afternoon. To this point I’d seen the eggs but I had yet to see an adult asparagus beetle. All of that changed when I went to the asparagus bed on a warm afternoon. There were adult beetles everywhere, chewing on the spears and mating away.

Asparagus Beetles

Asparagus Beetles

If I were a commercial grower of asparagus I’d have to do something to control these beetles. Their chewing can cause the spears to be twisted or deformed and the eggs would make the spears unmarketable. But as a home gardener, I can be a little less aggressive in dealing with this insect. I don’t care if the spears of asparagus aren’t perfectly formed. The eggs can easily be wiped off of the spears and if I miss a few, I just see it as a chance to add a little insect protein to the asparagus!

The presence of these insect did get me thinking about why I’m noticing them this year. I think it all has to do with cultural practices. In years past I would mulch the asparagus in the summer with straw and then in the spring burn the mulch and the dried ferns to clear the bed. I didn’t know it at the time but while clearing the bed with fire I was also killing most of the overwintering beetles.

Mating Asparagus Beetles

Mating Asparagus Beetles

With changes in the neighborhood I’ve replaced the spring burning with mulching the bed with wood chips and cutting the ferns off in the fall. What this means is that I’ve started to provide a perfect environment for the adult beetles to overwinter.

This fall I plan to remove most of the mulch from the beds. I might leave the ferns in the bed and go back to burning them in the spring. The other option is to cut the ferns in the fall and then go over the bed in the early spring with a propane weed torch. This would burn off the bottoms of the old fern stalks and kill many of the overwintering beetles.

In the meantime I’ll be keeping a close eye on the asparagus bed. Harvest season is coming to an end and once the ferns have fully developed I’ll be making sure that they’re not being defoliated by the beetles. This could weaken the plants and ruin next year’s harvest. If it gets too bad, a little pyrethrin spray will help to keep the beetles in check.

While asparagus beetles can be a problem, now that I know about them and their life cycle, I think I can get them under control. Cleaning the bed in the fall and using a little fire in the spring should be all that’s needed to limit the number of asparagus beetles in the garden next year.

 

The Rhododendron That Shouldn’t Thrive

Rhododendron Close Up

Rhododendron Close Up

It’s rhododendron time here in PA. There are two rhododendrons growing in the yard: one came with the house and is large and thriving while the other was planted a few years ago and is struggling to hold on to life.

The strange thing about this is that the plant that’s struggling is growing in a location where it should be thriving. The one that’s thriving is growing where it shouldn’t be able to survive.

In nature, rhododendrons are bushes that grow in the understory of forests. They need to have a moist environment because their roots tend to be shallow and dry out quickly. They also prefer to grow in dappled light where they aren’t exposed to the full energy of the sun.

In theory, that’s the sort of environment that should be best for them when growing in a yard. My struggling rhododendron is near a tree where it gets some sun but is protected from the heat of the day. The thriving bush is planted on the south side of the house where it bakes in the sun until around 4pm. And to make matters worse, this rhododendron is planted in a small opening surrounded by a concrete patio on one side, a black topped driveway on another and a brick walkway on the other two sides. This is one of the hottest and driest spots in the yard, yet it grows! (I know of someone else who has a great rhododendron that’s on the southeast side of the house sandwiched between the house and a concrete slab!)

rh1

I don’t know what to say about this strange occurrence.

Maybe part of the answer is in something that I’ve noticed as I see rhododendrons in other’s yards. I rarely see a young bush; the ones that are thriving are old and established. This makes me wonder if the older varieties of rhododendron are hardier plants than the ones available now. Who knows?

What I do know is that I want to spend this year trying to get my struggling rhododendron to thrive. As I said, it’s in a good location – at lease in theory. I want to be more diligent about watering it. I also want to check the pH of the soil – rhododendrons do better in acid soil. Even though I’m not one to nurse along a struggling plant, I’m willing to give this bush some special attention for a year or two and see if it makes a difference.

Maybe it will. If it doesn’t, I’ll send the small bush to the compost bin, knowing that there’s another rhododendron in the yard that’ll blossom every spring. It might be in the “wrong” location and should be dead but it’s apparent that no one’s told the rhododendron!

Gloxinia – Close-Up Photoshoot

The gloxinia are one of my favorite flowering houseplants. Right now I have a purple one that’s in bloom so it seemed like a good time to take some pictures. I was amazed at some of the close-up shots. There’s no Photoshop tricks to these pictures; a very short focal length gave me these interesting results. When you get close to a gloxinia flower you can see the unusual shaped stigma of the pistil and the fused anthers of the stamen. As you focus deeper into the flower, it looks like you’ve entered another dimension!

Flowers are great to look at but I especially like to get really close and see the details of the flower in detail! (You can click on the photos to enlarge them)

Gloxinia

Gloxinia

Note the Bow Shaped Stigma

A Four Lobed Bow Shaped Stigma

 

Moving into the Flower The Stigma

Moving into the Flower
The Stigma (this one has three lobes)

 

Moving Deeper into the Flower The Fused Anthers

Moving Deeper into the Flower
The Fused Anthers

 

All the Way to the Back of the Flower

All the Way to the Back of the Flower

Propagating Perennial Hibiscus

I’ve written before about the Southern Belle hibiscus that I have growing along a fence. The plants grow well and are covered with huge blossoms during the summer.

Southern Belle Hibiscus

Southern Belle Hibiscus

I have three plants but I want a fourth to fill in an empty pot along the fence. I grew the plants that I have from seed but I’m finding that Southern Belle is a variety that’s no longer readily available as seed. I considered dividing one of the clumps but that seemed like it would be a lot of work – the mass of roots and stems of the existing hibiscus is large and well established.

Then it hit me – take a cutting. Many plants can be propagated by taking a cutting of a stem and rooting it. The hibiscus shoots are just beginning to grow and I thought that these shoots might be perfect for rooting. Herbaceous plants are usually easy to root as long as the stems aren’t too woody. The hibiscus shoots that are coming out of the ground are far from woody; all of the tissue is very new and soft. If any part of a hibiscus should root easily, it should be these shoots.

So I cut a shoot, trimmed off the bottom leaves (these shoots are so young that the leaves aren’t even full size) and put it into a peat pot with sterile potting mix. As an added help in rooting, I dipped the cut end of the shoot in rooting compound. This compound contains the chemical indole-3-butyric acid (IBA), a plant hormone that stimulates adventitious root formation. While the mechanism isn’t well understood, IBA has been used for years to propagate plants, particularly woody plants. I doubt the hibiscus cutting needed the IBA but figured it couldn’t hurt!

Hibiscus Cutting

Hibiscus Cutting

After potting up the cutting, I put it into a Ziploc bag and placed it near a plant light. It’s now been about a week and the cutting is growing and when I tug on the stem, I can feel a little resistance, a sign that roots are beginning to form. I’m optimistic that this attempt at propagating a perennial hibiscus will work. Between the young shoot, the IBA and the season (propagating plants in the spring is often easier than other times of the year), I expecting to be able to plant this cutting in the garden in a few weeks. The plant will be smaller than the other hibiscus, but it’ll catch up with them in time.

Who needs Southern Belle seeds when there are shoots of existing plants that can be propagated?!

BugGuide.Net – Thumbs Up!

I’m not an entomologist. While I think insects are fascinating, my knowledge about them is pretty limited. This is especially the case when it comes to identifying insects that I’ve never seen before. Given that it’s estimated that there are over 8 million insect species in the world, identification can be a little tricky!

Mystery Larva

Mystery Larva

Case in point: insect larvae on a pigweed. Last year I found some kind of larvae chewing on pigweed. I took pictures and posted them on this site but received no identification information. I did a Google search using all kinds of terms to describe the larvae but I found nothing. I even sent the picture to the local Master Gardener program but they were no help at all. I’d come to accept that I might never know what this insect was.

But then I went to BugGuide.Net. This site has all kinds of information about insects and entomology. I’ve often gone to this site but hadn’t noticed that there was a tab labeled ID Request. I learned that after setting up an account (an easy process), you can submit photos of insects to the site and its members will help to identify the insect.

I thought it was worth a try so I downloaded my photo of the mystery larva to the site. Given the trouble that I’d had identifying this pigweed pest, I wasn’t too hopeful. But to my surprise, one day later, a member in New Jersey had posted a reply and solved my year-long mystery.

Pigweed Flea Beetle (from www.extension.org)

Pigweed Flea Beetle
(from http://www.extension.org)

What were those strange larvae crawling on the pigweed? They’re Disonycha glabrata, the pigweed flea beetle. I’d never heard of this insect before but when I searched for pictures of it, I realized that it’s a regular inhabitant of the garden.

Thanks to the help of BugGuide.Net, my mystery insect is no longer a mystery. It has a name, Disonycha glabrata or pigweed flea beetle, all thanks to a cyber community of “bug geeks.” If you want to learn more about insects and receive some help in identifying mystery insects in your yard and garden, give BugGuide.Net a try.

The Slowest Spring

I find that recently I haven’t had much inspiration to post on this blog. I’m not sure what that’s all about but I think part of it has to do with the weather – at least that seems like a good excuse!

Oak in Bloom

Oak in Bloom

After a cold and long winter, spring has come but it’s taking it’s time to fully arrive. There have only been a couple of days in the 70’s and the nights have been cool. All the plants in the garden seem to be in slow motion. I’ve only had to mow the lawn a few times; the perennials are just coming out of their winter dormancy; asparagus is just now ready to be cut.

A local garden writer whose ideas and opinions I respect posted that we’re about three weeks behind where we usually are at this time of the year. That seems about right – it feels more like mid-April than early May.

Now I know this will change. The forecast for the coming days does show a bit of a warm up and it looks like we’re past the point of having any more frost. But I’m still holding off on planting a lot of things, especially vegetables. While the onions and lettuce are doing well, the soil is still too cold to plant beans and summer squash. I could plant peppers and tomatoes but I know that if I did, they’d just sit in the ground waiting for warmer weather.

So I’m taking my time with planting and letting Mother Nature be the one who decides when I can plant the rest of the garden. It might be a while but the time will come.