Archive for Removing invasive weeds

Resistance is Futile-Plants that take over your landscape

Resistance is Futile-Plants that take over your landscape.

 

This blog is about attractive plants that take over your landscape.  They are tempting and for sale at most garden centers.

Star Trek The Next Generation came out 20+ years ago but I was busy building my landscape design practice and raising a stepdaughter so I missed the whole thing.

Maybe I’m just going to seed as I recently watched all seven seasons in short order. I encountered the Borg and was impressed with their ability to take over a universe. The Borg remind me of certain plants that will happily assimilate your entire garden and need to be avoided. 

Here’s a list of plants that are as devastating as the Borg and good at propagating their own kind without any assistance. They have an aggressive spreading growth habit and yet they are still sold at most nurseries and garden centers in spite of their thuggish nature. Be warned.

Foliage of houttynia 'Chamelon', is an aggressive spreader in Portland Oregon gardens.

Houttuynia cordata ‘Chameleon’ Photo Source

Here is a beauty of a beast: Houttuynia

Houttuynia cordata ‘Chameleon’ –  I’ve never known anyone who (once it was planted ever managed to get rid of it. It is famous for aggressive roots that will grow through other plants and overpower them. It can seed although it hasn’t in any of my clients gardens because I never use it.  Look at how cute the variegated leaf  is!

Aggressive Japanese Bloodgrass in Portlands' Raleigh Hills residential landscape design

Japanese Bloodgrass, Imperata cylindrica ‘Red Baron’, can spread indefinitely

Japanese Bloodgrass Spreads

Imperata cylindrica ‘Red Baron’ or ‘Rubra’- Japanese blood grass is a spreader but it can be dug out and eventually (as in years of work later) be banished but don’t sacrifice your time to this plant…you will be sorry!!

Aggressive Ribbon Grass in NW Portland parking lot is well contained by boulders.

Ribbon Grass, Phalaris arundinacea

Ribbon Grass is on the Fence

Ribbon Grass, Phalaris arundinacea, is a plant that can be very difficult to eradicate but if a designer suggests it for a contained area that doesn’t mean they are a newbie.  It is planted in a parking lot that I frequent. It’s been trapped there over 9 years and has not escaped. I myself have never used it in a design but it is very very low maintenance.   Here is an article regarding success in killing the ribbon grass. 

Front yard of North Portland Row House is lost to Aspens aggressive growth habit.

This stand of Aspens (Populus tremuloides) started out as one trunk!

Aspen Trees

Aspen trees, Populus tremuloides, are beautiful in a forest but not good for tiny city plotsOne tree will become many and fill your soil space with invasive roots that lift walkways, invade foundations and water lines and leave companion plants with no water or nutrition. See this great article from designer pal Beth Goodnight regarding the evils of aspen and some alternative suggestions.

Keep Mint in a Pot

If mint gets away from you – you will never get rid of it. Some people plant it in a pot and keep it on a concrete patio. The roots can escape from the pot and once it spreads in your soil you will have it forever so I never set my pot of mint into a planting bed. I like having mint for soups but it is strictly a container plant. 

Japanese Anemone in Portlands' Grant Park neighborhood in low maintenance residential garden design.

Japanese Anemone is beautiful but travels fast

Japanese Anemone and Bishops Weed in the Right Spot Only

Japanese anemone, Anemone sp., should only be used by experts. This one is very very seductive and over the top beautiful. It travels by root which is the problem. I like to use it in very low maintenance planting plans/landscape designs and in parking strips where it is easily contained. It doesn’t seem to invade the lawn so I’ve used it in plant borders too.

Bishops weed, Aegopodium podagraria, should be planted by people who know exactly what they are in for. It can be contained in the parking strip or a low maintenance planting where you have nothing but shrubs. Large shrubs with bishops weed as a ground cover can be a functional landscape choice. If I use it I have a rule:  You are not allowed to ever give a start of it to a friend.      

There are, of course, many plants besides my short list that should be avoided or used with caution. These plants are the stars of this blog because they are so attractive, tempting and readily available at your local garden center.

Warning: Roundup is on Trial

Tips to Keep Yourself Safe When Using Roundup in Your Dog-Friendly Garden

The first law suit claiming Roundup causes non-Hodgkin’s lymphoma started June 17th in San Francisco. There is new research indicating glyphosate, the primary ingredient in Roundup is a serious carcinogen and may cause other health problems. They (Monsanto) are accused of hiding the truth about the risks and paying industry influencers to help them do so.

It’s no use complaining that everything you read (even a note from your garden designer) says something is causing cancer. There are facts to work with and being cautious is logical. I will be following this trial and the science closely and will share what I glean.

Using Roundup?

Here is a very good tip: buy it pre-mixed so you don’t spill the concentrated form on your garage floor or on your skin while mixing it up. Read that long label. Wear protective gear, including appropriate gloves. Protect your skin from any contact so no shorts or flip flops. Make sure the cap is on tight when you buy it. I had a bottle slosh all over me at Fred Meyer.Dog on playground slide dog friendly landscape in Portland Oregon

How long do I keep people and pets away from treated areas?

Read the label. The old rule was the area you treated had to be completely dry. Who knows what we may learn but remember dogs will eat grass while the Roundup is still inside the blades regardless of whether it is still wet or not. The product is now inside my dog. I’m not a chemist or a licensed pesticide applicator but I am sure I don’t want my dog eating treated grass and I don’t want the wet product on my skin or on my dog.

Why use it at all? Protecting our natural areas from invasive weeds!

Glyphosate has been extremely helpful where we are struggling to protect our native plants. Here in Portland the volunteers who protect Forest Park were using glyphosate to remove english ivy which threatens Forest Park. As usual, a black and white answer, while simple to comprehend, often does not address the complexity of life.

I promised if news came out that I felt was important to my clients lives, I would say so. Here is an article from August 2018, which reports “Monsanto, the maker of Roundup, was found liable in a lawsuit filed by a school groundskeeper who said the company’s weedkillers caused his cancer.” My goal is to inform, not to scare. If you use Roundup please do so with a healthy dose of caution and the right protection.

I want to keep us in touch and keep you informed. I publish tidbits to Facebook and photos to my Houzz page as well as monthly blog posts. Contact me through the websiteemail or call 503-223-2426. It always great to hear from new and old clients.

 

Garlic Mustard

Garlic mustard 2

The first year leaf of garlic mustard (typically called the leaf rosettes).

What is garlic mustard (Alliaria petiolata)?  This cool-season biennial’s leaves and stems emit the smell of garlic or onion when crushed.  Plants are 12 to 48 inches in height, and in their second year, produce numerous white flowers with four separate petals.  Garlic mustard is the only plant of this height in the woods with white flowers in May.  Hand pulling before flowering is recommended.  It is believed to have been brought to North America by European settlers for use in cooking and medicine.

Here is the link to a brochure created by the Oregon Department of Agriculture:  http://www.oregon.gov/ODA/shared/Documents/Publications/Weeds/GarlicMustardBrochure.pdf

How does it spread?  This weed spreads exclusively by seed.  The plant exudes a toxin from its roots into the surrounding soil and kills off competing seeds (the allopathic substance actually prevents germination of any seeds except its own!).  It also stunts the growth of nearby plants.  English Ivy in all its evil glory can’t hold a candle to this marauder.  It’s clearing the way so this plant can take the next area over.

Why it’s bad, very bad:  The concern surrounding garlic mustard comes from its ability to aggressively invade a woodland community and displace the native plant community to include grasses, shrubs, perennials, and tree seedlings.

weed-clipart-A_Little_Girl_Pulling_Weeds_Royalty_Free_Clipart_Picture_081111-152171-530047How to remove it:  Mowing is not an effective control because plants will still bolt and seed.  Mowing spreads garlic mustard seed like wildfire – do not mow when seed pods are present (May through September).  Hand pulling the weed is easiest during early bolt (2nd year).  Difficult during rosette stage (first year) except for small patches.  Multiple years are needed to exhaust seed bank.  Pull at base to avoid breaking stem.  All pulled plants should be bagged and removed from site (seed will set and/or plant will  re-root).

Garlic mustard mature

Mature garlic mustard

If you must use chemicals, use a product that contains glyphosate or Tricloypr.  To avoid damaging native forbs, spray the rosette stage during late winter/early spring.  If not sure how to identify rosette stage, you can spray during flowering.  Fall application to the rosettes (after some rain evens so plants are growing again) may also be effective.  Sprays at height of summer will not do much.  Use aquatic formulations when spraying near any body of water.  A combination of chemical and hand pulling is very effective – pulling bolted plants and spraying right after pulling.

I am not suggesting growing it for cooking, but while eradicating it from your property, you could get even with it by making a very tasty pesto from the leaves.  Here’s just one recipe I found on line:  http://www.mnn.com/food/recipes/photos/6-edible-invasive-species-recipes/garlic-mustard-pesto

Five Important Garden Tips

Five Important Garden Tips You Need

Treating blackberry and ivy with Roundup in the spring and early summer is pretty much useless.  There is a time when these plants are most susceptible to herbicide. It’s a million times more effective in late summer and early fall.   In an ideal world we would not use herbicides at all, if you are going to use them you want to use them sparingly and at a time when they will be effective.  For information on how to do it right see my blog:  Treating blackberry and ivy .

Over watering or under watering new plant material.  Your common sense will kill your plants if you don’t have the specific information for the specific plant type.  You can’t water a new tree the same way you would water your petunias.  I insist my garden coach clients have a written watering plan for the first two years of their new landscape.  I tell them how long to water and to hand check the soil to see if their efforts are successful.  Last, but not least, if you’re watering every day you are in line for losing a lot of new plant material.

Sedum s Red Carpet in winter

Colorful tough ground cover for full sun

Plant labels lie.  Trust me it’s not a conspiracy, but they write the label so that it makes  sense for the entire country.  In the Northwest we have the ideal growing conditions so plants will grow taller and wider than indicated.  In addition, just because a plants’ mature size is 15’ tall, does not mean it will stop growing once it gets there.

Light.  Labels don’t have enough room to explain the complexities of sunlight, let alone the four different kinds of shade.    Great Plant Picks is a great information resource in many ways, and has an excellent explanation about the different kinds of shade.   There is no perfect solution, even checking the Web will get you four different suggestions for light requirements on a single plant.  This is why experienced gardeners often move plants that don’t seem to thrive in the first location they select.  Others hire designers who know these things first hand.

Carol on a garden coach appointment.

“Thank you so much for all your information today and your helpful phone call Saturday.  I was pulling out plants in my mind as I was going to sleep last night.  I can’t wait to get started!”  D’Anne Oneill

Pruning.  My best advice is don’t let your father-in-law prune your Japanese Maple!  Do not do hedge pruning on plants that are not hedges.  You need to learn how to do a thinning style of pruning. While I certainly advocate for hiring a garden coach (since I am one) you can learn from a local nursery, community college or someone who has trees and shrubs that don’t have a bunch of stubs on them.  We want pruning that will enhance a plant’s natural and unique shape.