November: To Do in the Garden

On By durhammastergardenersIn Gardening calendar

by Gary Crispell, EMGV

Rain glorious rain and it isn’t cold yet, at least not as I write this. What more could one ask for? Now that there’s some moisture in the ground it can really be planting season. I have a large number (more than 70) mostly perennial plants to stick in the ground, but I haven’t been able to get a shovel into it. Now it is “just do it” time. Perhaps I shall first make a chiropractor’s appointment for next week. So, that’s my plan. What are you doing with the rest of your fall?

Lawn

If you have a warm season grass lawn all you need to do is keep it relatively free of leaves. If, on the other hand, you have a cool season grass lawn, you are still cutting it 3.5  to 4 inches tall AND keeping it relatively leaf free. Continue the battle with fire ants.

Fertilizing

Not much going on here. If your lawn’s soil pH is low, less than 6 (I’m sure you were astute enough to get the soil tested before NCDOA starts charging for the service later this month), apply the recommended amount of lime. A good way to incorporate it into the soil is to core aerate the lawn before the application.

Wood ashes from your fireplace can be spread on your gardens and shrub beds. Be careful to avoid acid-loving plants such as azaleas, camellias, gardenias, etc.

Planting

  • Let me repeat, “Fall is for planting!” There is still lots of time to add/transplant plants in your landscape (per your PLAN, naturally).
  • Plant one-year-old asparagus crowns now.
  • Sow a cover crop over the veggie garden if it is done for the year. A planting of annual rye, wheat or barley will help prevent erosion and keep weeds to a minimum. Besides you can just till it into the soil in the spring as a bonus.

Pruning

  • After Jack Frost has claimed the last of your herbaceous perennials, including existing asparagus, they can be cut back to the over-wintering rosettes or the ground.
  • Dead and/or diseased wood can be pruned out at any time.
  • Weeds and undesirable trees can now be removed without the aid of three bottles of water per hour, head sweat band and insect repellent.

Spraying

Surely by now you have cleaned up and put away the spray equipment. If not, just do it.

Other stuff to do that will keep you outside

  • As mentioned earlier, add lime where recommended. No fertilizer until spring.
  • Walk around the yard on mild days; It may be awhile before we see any more of them.
  • Okay. You can go inside now and order those fruit trees and vines you’ve been talking about. They will be delivered in time for planting in February or March. (Did you know hardy kiwi will grow well in a sunny place and produce a prodigious amount of fruit?)
  • While you are in there look at your landscape and/or gardening plan and make adjustments based on this year’s experiences.
  • Oh, yeah.  Don’t forget to stuff that bird, mash them taters, and bake that punkin pie.

May your Thanksgiving be
bountiful enough to share with those
whose Thanksgiving will not be.

An Introduction to NCSU Plant Disease and Insect Clinic

On By durhammastergardenersIn Common questions, Gardening information

by Andrea Laine, EMGV

You know you’re a serious gardener when you get excited about preparing a sample for the NCSU Plant Disease and Insect Clinic. I just wish I had engaged this problem-solving staff sooner and I hope you will learn from my experience.

Over the last three or four years, the mature evergreen azaleas in my landscape – of which there were many – began to succumb to a sudden dieback. Where there was once dark green glossy leaves and abundant flowering, seemingly overnight a swath of vertical branches would turn brown and die. I was alarmed, but knew not what to do. So, I did next to nothing: I trimmed out the crispy parts and hoped for the best.

I am ashamed to admit this experience was after my master gardener training. In training we certainly learned about the services provided by the Plant Disease and Insect Clinic, but either I didn’t think my plant problem was important enough to bother someone at NC State, or I was too lazy to prepare a sample. Probably a little of both.

The photo on the left was taken in 2013. The one on the right was taken summer 2019. It’s heartbreaking to see how robust the azaleas once were and are no more. Photos by A. Laine.

Inspired to act

Fast forward to this summer when two things happened that inspired me to act. First, the mysterious dieback attacked a stand of azaleas that are a key structural element in the design of my landscape (see photos above). And secondly, I noticed the exact symptoms on a few azaleas in a Durham neighborhood far from my own. The problem no longer belonged just to me; I resolved to seek a diagnosis on behalf of all of us.

My first step was to collect a soil sample from the vicinity of the azalea with the most recent dieback. The results showed that the soil pH was too high – 6.2 – where azaleas prefer a number between 4.7 and 5.3. Phosphorus was high and potassium was a little low. While all that is not a great situation for these acid-loving plants, it did not explain the sudden dieback. I needed to delve deeper.

I decided to access the NCSU Plant Disease and Insect Clinic. (You’ll find a direct link to it on the right side of this blog’s homepage as well as in the list of resources below.) I dug up a smaller azalea that had browned out a year or so earlier, left a good bit of the roots and soil intact and plunked it into a double plastic bag. Back indoors, I downloaded a submission form from the Clinic’s website, filled it out to the best of my ability and brought it and the sample to the master gardener office where I enlisted the help of our County Ag Agent Dr. Ashley Troth. Ashley submitted the sample on my behalf and we included digital images of the affected plants in my landscape. The more information a client can provide, the better will be the diagnosis and recommendations.

I had decided to remove these small, scraggly azaleas from the landscape anyway. So, I used half of one as my sample to the Plant Disease and Insect Clinic. Photo by A. Laine.

A diagnosis

A week later the diagnosis was in:  Symptoms are typical of Phomopsis dieback, a fungus disease. “The disease can be very serious if the fungus moves into larger branches and the base of the plant. This dieback was found down into the base of the plant submitted,” wrote Shawn Butler, an ornamentals diagnostician. “Presence of this disease,” he continued,  “often is an indicator of stressed or injured plants. Photos show that there is probably a problem in the root zones of these plants.  No root rot pathogens were isolated from these roots.  If the plants have been water-stressed in the past, then that might be the primary problem.” 

He also sent a root sample out to check for presence of damaging nematode populations. Some parasitic nematodes were found but populations were not high enough to cause damage.

A new pledge

I will take away at least two lessons from this experience (and I hope you do, too). The first is to seek help sooner, and the second is to not ignore long-established shrubbery. (These azaleas were planted at least 20 years ago.) The plants I inherited with my landscape deserve tender-loving-care equal to that which I provide to the plants I personally select for the landscape. 

Yet another azalea is affected. Removing it would leave a hole in the bush to the right as they have grown together over the decades. Photo by A. Laine.

Resources & Further Reading

How to submit a sample to the clinic: https://projects.ncsu.edu/cals/plantpath/extension/clinic/submit-sample.html

Meet the staff
https://projects.ncsu.edu/cals/plantpath/extension/clinic/about.html

Fees for the Clinic’s diagnostic services: https://projects.ncsu.edu/cals/plantpath/extension/clinic/services.html

Azalea care – a factsheet from Clemson University
https://hgic.clemson.edu/factsheet/azalea-care/

A comment about old azaleas from Louisiana State University
https://www.lsuagcenter.com/portals/blogs/southerngarden/problems-with-old-azaleas