Friday, October 30, 2009

Fatsias and Camellias at City Nursery Farm

I know I have already written about the Camellias at City Nursery. They are so impressive that I have to tell you all about them again. If you are an architect, designer or landscaper, take notice.

The Sasanqua Camellias (budded and blooming) are incredibly vigorous- from a distance they look like robust Ligustrum shrubs. In the landscape, these Camellias would work as individual specimens (especially the white-flowering 'Autumn Rocket') or in a group to create an instant hedge.

As you can see from these pictures, the entire crop is PERFECT- dark lustrous green leaves, uniform growth habit, fully budded:
And they are big. These 30-gallon Camellias will have an immediate impact in the landscape:On to the Fastia....

Fatsia (Fatsia japonica) are notoriously difficult to grow in a container. If the soil pH is off or they are even slightly overwatered, they develop infections from Phytopthora and Fusarium. Many of the crops I scout consistantly look like this:
On the other hand, the crop at City Nursery has been healthy all year. These plants have well-developed, white roots and lush foliage:And they all look like this. The wholesale price is very good (call me if you want to know) and you can feel confident that you are going to get a high-quality plant.

Tuesday, October 27, 2009

My tipsy bird

Last winter, I came home one day to what I thought was a dead bird on my deck. It was so sad.

I picked her up so that I could bury her.....and I felt her heart beating slowly. And then her eyes opened. She was okay!
What was so amazing was that she didn't seem nervous at all that I was holding her. I have held other birds (including a couple that have accidentally flown into my house) and their hearts would always beat rapidly. But this bird was content being held.

I placed her on my leg and took a few pictures- and she willingly obliged. Such a beauty!

Then I filled a dish with water and perched her on the edge. By this time, I had come to the conclusion that this wild bird was destined to be my pet. She would make a great companion, I decided. She'd travel with me to scout nurseries and gardens......Have I mentioned that I am completely delusional?

As I held my new found friend, I expanded her wings, checking to see if she was injured. That's when I noticed the red wax-like tips on her wing feathers. A Cedar Waxwing!

I found my bird field guide to make sure I had identified her correctly (I know, I am such a dork). That's when I realized what was really wrong with my bird....she was drunk.

I learned that Cedar Waxwings (Bombycilla cedrorum) are fruit eaters. In the late winter, many of the berries they feast upon have fermented. As they gorge themselves on these fruits, they can become drunk and disoriented. Consequently, they accidentally fly into windows and buildings. Once they sleep off their buzz, they rejoin the flock (if they aren't devoured by a cat first).

Heartbroken that she wasn't going to be my pet, I made her a drunk tank and set her in it.
An hour or so later, she flew off and seemed fully recovered.

The berries on the Weeping Yaupon (Ilex vomitoria 'Pendula') tree by my office window are starting to ripen- Cedar Waxwings love this plant. Seeing the reddening fruit reminded me of my inebriated bird. You think she remembers her afternoon with me?

Sunday, October 25, 2009

Plant Pest: Powdery Mildew

It's mildew weather- Powdery Mildew weather.

While Powdery Mildew will not usually kill a plant, it does distort growth, reduce flowering, discolor foliage and impact vigor. Not desirable for garden or nursery.

Before treating for Powdery Mildew, make sure that you have properly identified the disease.

Powdery Mildew is commonly confused with Downy Mildew. While they are two very different fungi, I understand why they are often misidentified: They both have "mildew" in their names and they are characterized by a white growth on the leaves. In addition, Powdery and Downy Mildews tend to occur in the spring and fall when temperatures are lower and humidity is high.

If you think you have Powdery Mildew, look to see which side of the leaf is covered with the white growth. If it is on the upper side of the leaf, it is probably Powdery Mildew (Downy Mildew sporulates on the underside of the leaf).

Then look at the growth pattern. Powdery Mildew has diffuse margins while Downy Mildew creates angular leaf spots. This is illustrated in the image of the Japanese Magnolia below:
The white growth is the reproductive phase of the fungus, Oidium. The vegetative portion of the fungus is actually inside the leaf, taking nutrients directly from the leaf cells. The spores only appear when it is cool and humid.

See how the Dogwood leaf is purpling in the areas where there are spores on the surface? Those are the areas where the fungus has taken nutrients from the leaf. The premature fall coloration occurs because these areas of the leaf are not photosynthesizing properly.

The best way to prevent Powdery Mildew is to use resistant species and cultivars. Resistance has been bred into certain Crape Myrtles, Hydrangeas, Phlox and other plants.

If that's not an option and you have an infection:
  • Apply lightweight paraffinic oil as a coating to the leaves to provide good management. Spray the leaves on a weekly basis (when daily temperatures are below 80F) with a 1-2% solution.
  • Increase air circulation in the growing area to reduce the humidity level.
  • Grow where the plant gets at least partial sun during the day.
  • Rake up fallen leaves during the dormant season. Powdery Mildew overwinters as cleistothecia (survival spores) on these fallen leaves and will reinfect plants the following spring when the spores splash back onto the plants.

The powdery growth is made of these chains of round spores. These spores (conidia) are spread to new leaves and plants by air currents and the wind.*Above image from Cornell University Department of Plant Pathology.

Monday, October 19, 2009

I like fall.

Good riddance to flea beetles, aphids and lace bugs.

Sunday, October 18, 2009

Plant Pest: Magnolia Serpentine Leafminer

While this is just an occasional pest of Magnolia, the Serpentine Leafminer causes damage that is highly visible (I kind of like it). All Magnolias species are susceptible to this pest, but I rarely see it in nurseries or landscapes. Scale and Twig Borers are much more common and damaging to Magnolias in the South.

Injury is caused by the larvae of a specific moth, Phyllocnistis magnoliella, which burrows through the upper leaf epidermis in a meandering fashion.
The life cycle has not been really been studied, so there is not much information about when to time pesticides to control this pest.

Luckily, this Leafminer is seldom a serious pest of Magnolia (and it does not infest any other genera of plants). The best way to manage the Magnolia Leafminer is to remove infested leaves as the trails appear.

Begin looking for injury in late summer- Damage will begin to appear in early August if the moth has laid eggs on the leaves.

Saturday, October 17, 2009

High Quality: Wellie Boots

As y'all know from some of my previous posts, I believe in buying quality tools. Just as a hairstylist needs a good pair of scissors to cut hair properly, a horticulturist needs a good pair of shears to prune trees properly.

The same goes for outdoor clothing- particularly when it's cold and/or raining.

As I learned, a new pair of blue jeans are not the best things for foul-weather protection. But my Hunter Wellies are a dream.
I love them. They are completely watertight and have a good gripping sole. I think that any product that has been made since the 1800's falls into the "tried-and-true" category.

These standard green Hunters were bought from Gempler's, a mail-order nursery supply company for $99.

I didn't realize it until now, but Hunter boots have become quite fashionable lately and apparently you can get them at many high-end retailers like Nordstrom and Saks. I thought that the only way to get them was through an ag-supply company!

Even Jimmy Choo has a line of Hunter boots now, complete with reptilian embossing and strange outer socks:

For horticultural (and economic) purposes, I'd stick with the originals.
Through this "research," I did find a Hunter accessory that I need for this winter: the Hunter "Fleece Welly" socks. Admittedly, rubber boots do not hold in heat at all, so I am looking forward to this addition to my winter wardrobe.

Thursday, October 15, 2009

This is so typical II

I don't have TV anymore because I watched (loved) it too much. Since I canceled cable ten months ago, I haven't paid much attention to weather forecasts. And so far, it hasn't been much of a problem.

Until this week.

I left the house early Wednesday morning for a 2-day scouting trip. Uncharacteristically, I loaded the car the day before with every thing I thought I would need.

Microscope? Check. Pruning shears? Check. Toothbrush? Check. Long pants? Nope.

I didn't realize I had forgotten to grab a pair of jeans out of the dryer until I was heading north on the interstate. I really didn't think it would be a problem because I could simply wear my shorts both days.....but then the rain started. And the temperature quickly dropped from a balmy 70 degrees to a terrifying 49 degrees. Since I haven't checked a weather forecast since 2008, I didn't know how much colder it would get. But I knew I was not dressed appropriately.

I was going to look like a fool if I didn't get some pants, so I stopped at an outlet mall just off the interstate and bought the first pair of jeans that I found that were long enough. Wearing them out of the store, I thought, "Ah, crisis averted."

It rained the whole time I was on my trip. The constant chill and dampness made the palms of my hands take on a bluish tint.

Only my hands weren't cold.

In reality, my new, dark denim pants were wet and were staining everything with blue dye. Not only were my hands blue, but now my car interior is blue, too! Nice.

I did remember to pack my boots though!
I think there are two lessons that can be gleaned from this experience:
1. Always wash your jeans before you wear them.
2. Always pack at the last minute so you don't forget anything important. (ha!)
Other than staining the light gray interior of my car, it was a good two days. As luck would have it, rain makes it easier for me to diagnose fungal diseases like Downy Mildew.

The white fluffy stuff on the underside of this rose leaf are the spores of Downy Mildew, caused by the fungus Peronospora sparsa. You can see why it has the specific epithet "sparsa":

Tuesday, October 6, 2009

Have a plant problem?

One of the services Scout Horticultural Consulting provides is the diagnosis of individual plant problems. Plants (or the affected parts of a plant) can be sent to our lab for a microscopic diagnosis, treatment recommendations and cultural information.

Diseases and insects move quickly through a greenhouse, nursery or landscape. Plants are examined when they immediately arrive to begin the diagnostic process. I make it a priority to contact you with either a diagnosis or preliminary assessment within 48 hours.

Complete this form to send a sample to Scout Horticultural Consulting:Once the SHC website is completed, this form will be available there as a pdf.

Saturday, October 3, 2009

Horticultural Blights and Plagues

When a plant dies in a garden or nursery, my clients are often concerned that it will spread to all other plants in the area.

And this can happen in certain conditions. For example, the fungus Botrytis can blight many types of bedding plants in a greenhouse if the humidity is high and the leaves are staying wet.

Thankfully, indiscriminate blights are not usually a problem. Plant pathogens tend to be more host-specific. Take a look at this propagation greenhouse:Notice first that this greenhouse is well-maintained. There are no weeds, the plants are all the same age and it is organized. This is a good growing environment.

The Oakleaf Hydrangeas (on the right) have collapsed and are infected with a fungal pathogen.

It is significant that the Hydrangea macrophylla crop (with bright green leaves) is very healthy. They are growing right next to the diseased crop of Oakleaf Hydrangea (Hydrangea quercifolia) and yet are showing no signs of disease.

The take-home message is that if you are having a disease problem in your garden or nursery, don't fear that it will destroy everything.

If a large area of your garden, nursery or greenhouse is in decline, have the problem properly diagnosed. Then ask the following questions:
  • Are the plants being over- or under-watered?
  • Does the soil drain properly?
  • Are the plants in the right amount of sunlight?
  • What is the soil pH?
  • Is there too much mulch around the bases of the plants or are they planted too deep?
  • Is the irrigation water salty?
A fungus or bacterium may be the primary problem. But in my experience, if many different species of plants are affected, the growing conditions are generally to blame.


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