Wednesday, July 29, 2015

Bishops Weed - Control Options

What is Bishops weed?  
Aegopodium has several common names including Bishops weed, Goutweed and Snow on the Mountain.  Bishops weed can be found in the variegated form or a solid lighter color green plant. It prefers moisture and can tolerate sun or shade conditions.

Common Bishops weed grows to 10-12" in
height, shading out other plants in the garden.
It is aggressive and considered invasive, spreading from underground rhizomes and from seed, creating dense patches of ground cover that will crowd out other more desirable plants in the landscape.

Bishops weed can be used as a ground cover where it is contained by defined landscape elements like pavement boundaries or well defined and maintained beds. Incorporating Bishops weed into a mixed use garden or bed will invite a constant challenge of keeping the bishops weed from invading and taking over other plants.

Control Options: 
Control options are varied and you may need to use several strategies to successfully eradicate Bishops weed. An open bed area can be managed differently than a ground cover bed or even perennial bed.  The more attached you are to saving existing plants in an infested bed will limit your options. Even with aggressive control it can take a year or more for you to overcome bishops weed.

Simply weeding a garden bed may not be enough. The Bishop weed plant stem will snap off readily from the root or rhizome leaving the remaining plant part in the soil allowing new tissue to emerge. Keep in mind that plants create food or energy through photosynthesis which requires sunlight. Bishops weed is tenacious and will keeping coming back even with aggressive weeding. The plat spends energy producing new growth in an effort to collect sunlight - but if you can starve the plant of sunlight with timely weeding you can rob the plant of its energy and new growth will slow and ultimately stop.  Allowing a plant to grow back in and capture sunlight is giving the weed a second lease on life.

Bishops weed in two forms: the light green
small plant are newly emerged plants while
the dark green taller plants in flower have been
allowed to mature and will soon produce seed. 
Forking: Using a digging fork, you can lift and separate the soil just enough to pick the roots and rhizome plant parts from the soil. You are effectively hand weeding the garden, but you're not just taking out the top growth, but also the part of the plant that stores energy producing new growth.  This can be tedious and challenging in a dense planting, but can be effective at thinning the crop and getting areas of the bed under control.

Mechanical removal: This is a fancy way of saying weeding, removing the top growth from the bed by hand weeding, hoeing or even using a line trimmer in larger open bed areas. The goal is to remove the leaves that can photosynthesize to create energy for the plant. Regular and consistent weeding is an option, particularly in beds that are dense with desirable plants.

Block Sunlight: Open bed areas can be covered with black plastic to prevent sunlight from reaching the plants. Black plastic will absorb the sun's heat, deflect water and essentially bake the underlying plants. It may take a full season before the plant is successfully killed in this manner. Pin or weight the plastic sheeting down, but do not mulch over it.  You'll want the sunlight to reach the plastic and if you do mulch over the plastic it will hamper your ability to remove the black plastic when the time is right.

Chemical control: Spraying a non-selective herbicide like glyphosate (i.e. Round-Up) is an option in open bed areas and where collateral damage to surrounding desirable plants is not an issue. Glyphosate is designed to be absorbed through the leaf tissue and will systemically kill the plant. You could alternatively use an organic product like Burn Out, but this essentially only scorches the leaves - which helps to prevent the plant from photosynthesizing, but it won't kill the plant right away requiring repeated applications.

In our experience spraying small, less mature plants is more successful in knocking back Bishops weed than spraying larger mature plants. If possible, we may line trim taller and mature plants first and then return to spray when the new plants are relatively small and likely to simply disappear after dying off. Large dead plants don't just disappear and are unsightly in the meantime.  Repeat applications will be necessary as new plants reappear.

The slow, methodical and tedious process of removing the plant by hand can be enough to get even the most persistent gardener to call it quits. Alternatively, while it may cause heartache in the short term, a heavy handed approach of removing everything from the bed may be more efficient and prudent in certain circumstances. Heavily infested beds can be cleaned up, managed and allowed to remain fallow until you are certain the bed is clear. You can then plant with confidence and know that your investment will not be overrun by Bishops weed.

If you do decide to clear out a bed, a word of caution. Saving certain plants from the bed which are transplanted to new locations or temporary holding areas can carry Bishops weed into other areas of the yard, compounding your problem. Sometimes it is better to simply start over and not try to save any of the plants so you can be certain of your success.

Regardless of the method used, it will take patience, time and the will to win this battle. Persistence is the key.

Monday, July 20, 2015

Controlling and "eliminating" creeping bentgrass in the home lawn

One challenge for many Heights-area homeowners is the gradual infestation of creeping bentgrass in their lawn. Bentgrass is a low spreading turf type that does not blend well with turf that grows upright like blue, rye and fescue and when left unchecked has the potential to take over large lawn areas due to it's spreading growth habit.  The challenge has been how to deal with this tenacious 'weed'...

Bentgrass by itself if managed properly creates a very pretty lawn. However, the required maintenance regiment for a bentgrass lawn makes it much less desirable than other cool season turf selections. Bentgrass has different cultural needs (e.g. low mowing height, thinning stolen growth/thatch), has different fertility and irrigation requirements and has an increased susceptibility to disease and possibly insects. This high maintenance turf is not desirable for the family on the go with a limited budget for lawn or yard care.

Creeping bentgrass (light green patches) is easy to identify
in early morning hours when the dew settles on the grass.
Overtime many lawns begin to look like a patchwork quilt due to the mixture of turf types and their relative condition during a particular season. Bentgrass often shows the symptoms of diseases such as snow-mold in the spring and dollar patch in the summer - causing unsightly brown patches. When the weather is right the lawn will look okay or even good, but it can go quickly from normal or healthy looking today to... "oh my gosh, what happened to my lawn?" the next day.  

The reality is that the different maintenance requirements and susceptibility to disease creates a difference in appearance that cannot be readily accommodated with basic lawn care.  The best bet for a consistent looking lawn is to remove the creeping bent grass all together.   

Historical Control: 
Historically there have been few options to selectively remove bentgrass from the home lawn. The challenge has been no effective weed control product that can selectively remove creeping bent grass from the desirable cool season turf types like you would a broad leaf weed.   

Non-selective herbicides, like Round-up, will kill bent grass but will also kill any other grass plants that are sprayed. This is an effective option when replacing an entire lawn and where you want to kill the entire lawn.    

However, selectively killing spots is not full proof because the application will not get every small sprig or individual creeping bentgrass plant in the lawn - meaning it will return as the super small unidentifiable patches grow and spread larger over time.  

We also tried cutting out areas by hand or using a flame or torch to kill off patches of bentgrass.  Similar to non-selective herbicide, this approach killed the patches of grass but did not get all of the bentgrass in the lawn which allowed it grow back in overtime, furthering frustration.  

Today - Effective Herbicide Program for Control:
We have completed testing of a selective herbicide regimen and created an effective program to remove creeping bent grass from the home lawn. The program requires multiple late summer applications spaced at appropriate intervals to effectively control the bentgrass.  Depending on the level of infestation, once the creeping bent grass has been controlled we can spot seed or perform a lawn renovation so the lawn fills in with the desirable turf type.   

Creeping bentgrass patches show signs of stress and begin to
die off after one treatment from our program. 
The program is generally run from late July through early September prior to any necessary seeding or lawn renovation work.  A spring program is an option but becomes more challenging with large renovations that do not have irrigation leading into the summer.

Looking Forward:
Creeping bent grass was used extensively when homes were built in the early to mid 1900's before grass seed as we know it became readily available. Because of the preponderance of its use it will to some extent always be in the area.
Less than two weeks after the first application the tenacious
creeping bent grass plants are recovering - time for the next
applications before a lawn renovation is performed to
restore the lawn.

New lawns may still become infested with creeping bentgrass from neighboring lawns, animals or lawn care equipment that can help facilitate its migration. Before there was no guarantee that the creeping bent grass would not take over a lawn.  Today however, with a control program the creeping bent grass can remain in check. 

Our creeping bent grass control program will also manage other broad leaf weeds in the lawn.  

Call today for a free consultation.  

How much water does my lawn need?

When there isn't sufficient rain your lawn will need supplemental irrigation to keep it healthy and green.  While you do the have the option of letting a lawn go dormant during the driest of months, some water is still necessary to keep the crowns of the turf grass plants alive.

How much water does your cool season lawn need during the growing season?  It depends on your goals, but generally about one-inch of moisture per week is ideal and should keep your lawn green and growing.  How do you know if your lawn is getting enough water?  You can measure your sprinkler output and make a few calculations to get close.

Measure output: 

Rain gauge used to measure either natural
rain fall or irrigation output.
Available at: 
Set up three to five rain gauges (or pie tins or like containers) throughout the lawn area.  This will measure the amount you have applied and help you to determine the coverage.

Turn on the sprinkler or irrigation system for a measured amount of time. You may need to only run for 10 minutes, but depending on your supply (measured in gallons per minute or GPM), your hose, valves and sprinkler, you may need to run the water for 20 or 30 minutes to get a sufficient reading.

Measure the amount of accumulated water from the duration of the watering.

Calculate your output. If you measure 1/4" of water accumulation over 30 minutes, you will need to water for two hours to get one inch of water (1/4" divided by 1" = 4 x 30 minutes = 120 minutes or two hours).

Create your schedule: 
Now that you know your watering equipment's output you can set up a schedule that fits your lifestyle. According to the sample calculation, you'll need to water for 2 hours per week.  If you can fit in three waterings for the week at approximately 40 minutes, or four waterings for 30 minutes that would be best.

You may find that if you water for too long at one time you create puddles and water will run off the lawn. Avoid puddling, as the soil can't absorb any more water given the rate you are applying it and you're being inefficient and wasting water. It may be that you need to water for 20 minutes, change areas and then water again for another 20 minutes.

If you decide that you don't want to water a full inch per week, follow the math and reduce your watering for 1/2" to 3/4" of water per week. Depending on the weather, falling below 1/2" of water per week could result in the lawn going dormant.  Keep in mind, it is easier to keep a lawn green than to make it green. A lawn that has gone dormant will need four times as much water to bring it out of dormancy.

Watering Equipment: 
Nelson Oscillating Sprinkler
Available at: 
If you don't have an in-ground irrigation system, an oscillating style sprinkler is ideal as it mimics natural rain fall. We prefer models with a heavy metal base which minimizes the potential for movement. These sprinklers are not only ideal when watering new grass seed but also for established turf.  They cover a large area and sprinkling over a longer period of time allows the water to soak in, avoiding puddling.

Impulse style sprinklers generally come with a flat metal base or a spike that is inserted in the ground. The rotary sprinklers tend to not distribute water evenly across the area, causing dry and/or saturated areas.

Connecting multiple sprinklers together may not be feasible depending on your water pressure and volume. Each additional sprinkler uses available volume, decreasing the overall output of each sprinkler. If you plan to connect multiple sprinklers, measure your output to ensure you're getting enough water for each configuration you try.

Timers are very helpful to make sure you apply enough water and avoid over watering, particularly if you're not going to be right near the sprinkler to monitor. Use a battery powered digital timer (available at AM Leonard or home stores) to set your sprinkler to run for the desired amount of time based on your output measurements.  If you use the manual style timer that does not require a battery, measure your output to ensure the timing is accurate - these manual timers "estimate" time based on assumed rate of water flow and not actually on time.

Additional watering tips and advice: 

  • Water in the early morning hours (4 to 9 am) to allow the moisture to soak in without evaporating.  Excess moisture will evaporate as the morning sun heats up.  
  • Avoid late evening or overnight watering, as extended periods of moisture in the lawn may contribute to disease when the proper environmental conditions exist.  
  • It is preferable to water less frequently and for longer periods of time to get the moisture further into the soil.  Watering daily for 5 minutes is not as desirable as watering two or three times per week for 15 or 20 minutes (based on your output measurement and schedule).  
  • Shaded areas or lawn areas nearer to or under trees may require more water to compensate for the moisture the tree will absorb. In dry/shade areas you'll never practically be able to water enough to make both the tree and lawn happy - the tree wins nearly every time.  
  • Irrigation systems are a great tool to help manage the turf. Be aware of the output of the nozzles or rotors in your system and measure the output to dial in your timing.  Pop up nozzles put out more water in the area requiring less time per zone than do rotary style heads.