Groundcovers as Weed Control

by Andrea Laine, EMGV

After several years of trying to stay ahead of the weeds in my landscaped beds, I am coming around to an option I had not seriously considered before: planting ground covers as weed control.

Weeds

A variety of annual and perennial broadleaf weeds consider my yard home year round. Most of them I deal with by manually pulling. Dr. Joe Neal, professor of weed science at NCSU, recommends a frequency of every two to three weeks. Call me crazy, but I have never minded hand weeding. It feels meditative while I am doing it and afterwards, too, when I look upon my tidy garden.

Unfortunately, hand-pulling does not work for creeping woodsorrel (Oxalis corniculata L.). Even after a good rain and using a weed digger, it is difficult to get the root up on a younger plant. I find it easier to let it grow a bit which gives me more plant above ground to grasp and pull. But allowing any weed time to mature is dicey: weeds multiply so quickly and aside from being unsightly, rob your favored plants of moisture and nutrients in the soil. Encroachment is inevitable with woodsorrel as it spreads by rhizome, stolon and/or rapidly germinating seeds.

Ground covers

I used to view groundcovers as boring plantings; something you chose for a spot where it was difficult to grow anything else, or something non-gardeners or commercial properties planted to paint a spot green and call it landscaped. (Pachysandra comes immediately to mind.) But looking out my kitchen window last November at the way a few biennial columbine plants (Aquilegia canadensis) have reseeded so profusely over just a few years and now expertly cover a large part of the ground in one bed (i.e. no woodsorrell there), I am beginning to understand the concept and consider the possibilities.

ColumbineCover
Columbine isn’t traditionally considered a groundcover but it does the job nicely. All photos by A. Laine.

Groundcovers are plants that grow relatively close to the ground and spread freely to create a mass planting. The denser they are, the better they will be at shading the ground, thereby robbing weed seeds or rhizomes in the soil of the light needed to grow. If desired for weed control, seek out evergreen ground covers.

Columbine isn’t traditionally considered a groundcover but it does the job nicely. Some common groundcovers are already established in my landscape; pictured below left to right they are: golden creeping jenny (Lysimachia nummularia ‘Aurea’ ), creeping juniper (Juniperus horizontalis ), oregano (Origanum heracleoticum ‘Greek’ ) and Mrs. Robb’s bonnet (Euphorbia amyglaloides, ‘robbiae’).

 

A blank canvas

My thoughts of “too much columbine” have turned to “need more variety of ground covers.” Ground covers will be the new blank canvas. I am not choosing ground covers instead of more ornamental perennials and shrubs. I am choosing ground covers over open soil or a blanket of mulch which can be expensive and labor intensive when used for large spaces. Rather than fretting over too much columbine, I will consider it a placeholder and an organic mulch. When I am ready to plant something among it, I will simply edit out some columbine and insert a showier ornamental.

Where you have stubborn weeds, consider planting a more attractive groundcover. More plant suggestions appear in the links below.

Sources & Further Reading

About weeds

Identifying specific weeds:  https://projects.ncsu.edu/cals/plantbiology/ncsc/containerWeeds/list.htm

https://content.ces.ncsu.edu/are-you-weeding-frequently-enough-to-prevent-weeds-from-spreading

Creeping woodsorrel: https://plants.ces.ncsu.edu/plants/all/oxalis-corniculata-l/

About Groundcovers

This link lists dozens of groundcover suggestions for Georgia landscapes. Almost all will also survive in Durham County (Hardiness Zone 7).  https://secure.caes.uga.edu/extension/publications/files/pdf/C%20928_2.PDF

At heights of three to 12 inches, miniature roses can be groundcover:  https://content.ces.ncsu.edu/roses-for-north-carolina

Low-growing junipers make excellent groundcovers: https://content.ces.ncsu.edu/junipers-in-the-landscape

More groundcover plant ideas: https://www.missouribotanicalgarden.org/Portals/0/Gardening/Gardening%20Help/Factsheets/Ground%20Cover%20Plants66.pdf

 

Sometimes, Plant Adoption is the Best Option

By Jane Malec, EMGV

Long before my master gardener journey began, I loved bringing plants into my home. Quite a few years ago while passing by an apartment building at Michigan State University, I saw a dwarf leaf schefflera (Brassia actinophyllia) sitting on the front stoop.  There was a note attached reading “please give me a good home!” So, what was I to do? I officially adopted my first houseplant out of which grew a long habit of picking up plants and bringing them home. Some were gifts, others found like the first one and some were purchased with lunch money during lean years!

To this day, I always have plants in my home. I believe they make rooms more interesting by bringing in life and color. Foliage is the primary draw for most indoor plants I purchase. Unusual texture, shape or color starts my imagination working. Hmm … where could I put this little beauty? So, it stands to reason that while shopping at a favorite garden center a few years ago, a little Philodendron bipinnatifidum, or tree philodendron, caught my eye. It was no more than two feet tall and the foliage was very interesting.  I knew I had the perfect place for this tropical beauty.

 

 

Tropical landscape plants

Philodenron bipinnatifidum is in the Aracea family and is native to Brazil. It grows naturally in hardiness zones 10-12 especially along the edges of rivers in the tropical rain forests and in other areas such as Paraguay. It can also be found in the landscape of more tropical areas of the United States particularly in Florida were many landscape architects feature it in their designs. They are also popular indoor plants both in homes and commercial buildings.

The tree philodendron has a single and unbranched four-inch diameter trunk which and can grow up to 10 feet tall when planted in the ground. A plant grown in a container will  achieve a height usually less than six feet, directly correlated to the container size.  The foliage is unusual with its dark green and shiny leaves.  They can get really enormous growing up to 30 inches or more.  The dark green shiny leaves are enormous — growing to 30 inches or more. Each half of the leaf has eight to ten lobes each of which each can be 20 or more inches in length.  The leaves grow at the ends of the plant’s slowly elongating trunks and are held up on long petioles.  This feature also seems to be fascinating to golden retrievers!

IMG_1994
Leaf supporting petioles

Another interesting characteristic of this plant is the long dangling roots that grow up and out of the soil. They become more noticeable as the plant matures and may not even be present when you purchase a young plant. In fact, I didn’t notice them in my plant until I had it several years and it had grown at least a foot. Growing up to eight feet, these aerial roots anchor to the bark of tree philodendrons growing outside and will provide some light anchorage for the plant. There will still be roots in a container habitat but they will wind through the stems creating a spaghetti look which is really eye catching.

 

This philodendron will flower growing in a container but the plant needs to be 15 to 20 years old before it comes into heat. It is a beautiful petal-less flower which only lasts about two hours. Although it seems like a short life span, it would be amazing to see this unique flower.

Philodendron-selloum--Scott-Zona--CC-BY-NC
Philodendron selloum; Scott Zona, CC BY-NC – 4.0

Most pests and diseases tend to be caused by an overcrowded environment and/or over-watering. It prefers bright light but will tolerate lower light during winter periods. Also, as a container plant, it thrives outside during our Durham summers and it isn’t particularly fussy about humidity. I had my plant in quite a number of locations over the last few years. It wasn’t until recently that I situated it in a very sunny room of our home. Wow! It took off! The leaves started growing so fast that I could have sworn it was noticeable over night. I had to move all the other plants out of the area to give it room and, of course, it kept growing.

A New Home

About this time, I noticed that my church had a tree philodendron growing in nearly the exact conditions as mine and it was much larger! This wasn’t a good sign for what was ahead for my little kitchen corner. What to do?

For the answer I circled back to the beginning of my journey as a gardener of houseplants. I needed to find this plant a new home. Another bright yet empty corner in the church revealed itself. So, I convinced the church’s plant crew to adopt my tree philodendron and now I can visit whenever I want.  I love happy endings!

IMG_2385.JPG

Sources & Further Reading

from North Carolina State University Extension:  https://plants.ces.ncsu.edu/plants/all/philodendron-selloum/

from University of Arkansas Extension: https://www.uaex.edu/yard-garden/resource-library/plant-week/tree-philodendron-1-13-06.aspx

from Pennsylvania State University Extension: https://extension.psu.edu/philodendron-diseases

Tropical landscape plants: https://aggie-horticulture.tamu.edu/syllabi/308/Slides/PLTL1b.pdf

Unless otherwise noted, all photos were taken by Jane Malec. 

 

 

 

 

Briggs Avenue Community Garden is Accepting Applications

Have you ever wanted to plant a vegetable garden but don’t have the space or enough sun exposure in your yard? Consider joining a community garden! The Briggs Avenue Community Garden, located at 1598 S Briggs Avenue, has plots open for the 2019 growing season. Come learn edible horticulture with Durham County Cooperative Extension.

Where: Applications accepted through February at 721 Foster St, Durham NC
Contact: Cheralyn Schmidt Berry (919) 406-4606 or cschmidt@dconc.gov

 

Beware of Potentially Harmful Additives in Glyphosate Spray

poison-ivy
Glyphosate spray can help control poison Ivy, but beware of sprays with additives like diquat.

Glyphosate (sold under the trade name Roundup) is one of the most effective, widely used, and safest herbicides in the U.S.

But beware—always read the label. Ready-to-use herbicide formulations of glyphosate often contain diquat, a quick acting nonselective herbicide that may be harmful or fatal to humans if swallowed, inhaled, or absorbed through the skin. Skin absorption is particularly dangerous. In animal testing, prolonged exposure to diquat was shown to cause cataracts. It can also poison some species of fish and harm waterfowl.

The theory behind adding diquat to glyphosate is that it “makes the glyphosate work faster.” Ironically, a 2008 Study in Weed Technology showed that while the glyphosate-diquat formulation appeared to more quickly injure greenhouse plants, glyphosate alone had better long-term plant growth suppression.

I think I will stick with good old glyphosate—it’s been around since 1974.

That said, all herbicides carry risks—some studies have linked prolonged glyphosate exposure to non-Hodgkin lymphoma. Always read the label instructions and use herbicides with care. I use them only as a last resort. Avoid windy days, wear skin protection, goggles, a safety mask, and foot covering. And be careful with pets—they shouldn’t walk in any herbicide that hasn’t fully dried. Exposure to wet glyphosate can cause pets to drool, vomit, have diarrhea, lose their appetite, and seem sleepy.

It’s cold now, but gardeners will be battling weeds again before we know it!

— Marty Fisher, EMGV

Sources and more information:

http://pmep.cce.cornell.edu/profiles/extoxnet/dienochlor-glyphosate/diquat-ext.html

https://www.cdpr.ca.gov/docs/risk/rcd/diquat.pdf

http://npic.orst.edu/factsheets/glyphogen.html

http://www.bioone.org/doi/pdf/10.1614/WT-07-181.1?download=true

 

 

To Do in February

by Gary Crispell, EMGV

It’s February!! Those of us who are die-hard just-can’t-help-ourselves gardeners are

bluebird and box
male eastern bluebird and bluebird box. photo credit: Patricia Pierce on Flickr

nearly beside ourselves—right? I mean, we can do stuff! We can dig in the dirt (well, at least the dirt that isn’t moisture-saturated or frozen)! YEA!! Besides, it is almost March when we really get to do stuff. In addition to breaking out the shovels, rakes and hoes the chem-heads out there can start spraying and fertilizing. So, here goes. A prelude to Spring in the key of D# major.

Lawn Care
Cool season grasses (i.e. fescue and bluegrass) should be fertilized with a slow-release fertilizer following the recommendation of your SOIL TEST.

Late February/early March is the best time to apply a pre-emergent crabgrass preventer. There are several easy to use granular products on the market. Be sure to read and follow the directions on the label for safe and proper handling and application. Calibrate your spreader to ensure accurate application amounts; Too little will not give you effective control and too much may damage the turf.

Fertilizing
See Lawn Care above and Planting below.

Planting
And so it begins: The vegetable garden. The reason for some gardeners’ existence, for frozen fingers in February, summer sunburn and the endless supply of liniment in the medicine cabinet.

It is time for root vegetables and salad (and beef Bourguignon—which you can’t grow in the garden).  Plants that can go in the ground in February include cabbage, carrots, leaf lettuce, onions, potatoes, radishes, rutabagas, spinach and turnips. Work a little fertilizer into the soil that was tested in October (while it was still free to do so) following the recommendations of said SOIL TEST.

Be cognizant of soil moisture levels. It appears that Mother Nature is going to maintain that for now, but she can be really fickle.

Pruning
If you have been ignoring previous posts, now would be a good time to prune bunch grapes and fruit trees. Also due for judicious trimming are summer flowering shrubs and small trees.  That list includes Rose of Sharon (Hibiscus seriatcus) crape myrtle (Lagerstroemia species), butterfly bush (Buddleia davidii), and hydrangeas that bloom on new wood (Hydrangea arborescens & H. paniculata).

While you’re out there, whack back the ornamental grasses, too. The new blades haven’t emerged yet and the plants are looking a bit tired anyway.

Got some overgrown shrubs that you’ve been meaning to (or reluctant to) prune heavily? Go for it now.  I understand that if you’ve never done it before it can be a bit intimidating, trust me. The plant will almost always not only survive, but thrive. I am aware of the never-more-than-a-third rule, but sometimes that is not enough. If it needs to go back to 12”-18” … go for it.  Chances are, you and the plant will be glad you did.

Spraying
The orchard needs attention. Peaches and nectarines should be sprayed with a fungicide to prevent leaf curl. Spraying a dormant oil on the fruit trees will help control several insects later in the year.

Other fun stuff to do outside in February
– Perennials can be divided if the soil ever gets dry enough.

– Many landscape plants can be propagated via hardwood cuttings this time of the year.  Some of the plants in the category are crape myrtle (Lagerstroemia sps), flowering quince (Chaenomoles sps), junipers (Juniperus sps), spiraea (Spiraea sps) and weigelia (Weigelia sps).

– Bluebirds will be most appreciative of a thorough house cleaning before the spring nesting season. Remove all the old nesting materials and let them start afresh. It’s like clean linens for them.

Oh, yeah. Lest we forget … order flowers or other living things from the plant kingdom for your significant other. Just for the record, guys like flowers and plants, too. Happy Valentine’s Day y’all! Think positive thoughts about an early Spring and no late freezes.

 

Photo credit
Creative commons, copyright Patricia Pierce,  https://www.flickr.com/photos/47602497@N06/26758856348