Ask Ahlgren’s experts


In various areas of our lawn, there’s a lighter green grass than all the rest. Any idea what it is … and why the difference in color?

That light green grass isn’t a grass at all, it’s a “sedge” or “nutgrass.” A common weed in lawns, this yellow nutsedge often comes with topsoil that has been excavated around creeks and streams, since this type of sedge enjoys moist soil conditions (bottom ground). Before you do anything, carefully examine this sedge by pulling it from the ground, then rolling it between your fingers. You’ll notice the base of the stem is not round, but rather triangular. “Nutgrass” refers to the small nut-like bulbs that are on the ends of the root system—sedge spreads by these tips and particularly when the plant sets seed. It is best removed before it becomes established because it can be a pain in the neck (or your back). HOW DO YOU GET RID OF IT? You can hand weed the area … or simply spray a lawn herbicide specifically designed to eliminate “yellow nutsedge.”


What steps are necessary to prepare any lawn for the winter season?

  • Make sure your grass blades are cut short enough—do not scalp—to prevent any blades from “laying down” under potentially deep snow cover. Shorter grass is less likely to suffer from “snow mold” disease. Ahlgren Landscaping recommends cutting your grass to a 2 to 2-1/2 inch cutting height at your final mowing. Important TIP: we recommend gradually lowering your cutting height over the final three lawn cuts of the season—instead of trying achieve the height in one final cut.
  • Remove any leaf debris that might potentially smother your grass.
  • If your lawn routinely requires lime to “sweeten the soil,” late Fall is considered the ideal time of year to make a final lime application. Ahlgren Landscaping suggests you test your lawn soil every three-to-five years to learn how to improve soil conditions.
  • Ahlgren Landscaping recommends late Fall as the ideal time to apply any lawn winterizers or fertilizers. These ammendments are usually high in potassium, which helps your lawn prevent disease, while increasing winter hardiness. Although any top growth of your lawn is hybernating, any grass roots remain active to pick up soil nutrients. When you’re applying both lime and fertilizer, we recommend you space out each application by 14 days.
  • After the final lawn cut, don’t forget to service your lawnmower: Add fuel stabilizer to the gas tank and run the engine for 5 minutes to stabilize the fuel system. Detach the terminals from each battery post. We also suggest you drain the fuel tank and the carburetor. Take a few more minutes to do more lawnmower maintenance—such as an oil change and lube, cleaning the air filter, install a new spark plug AND replace worn out or damaged parts. Don’t forget to sharpen the lawnmower blade(s).

Someone recently told me Fall is the best time for lawn seeding and improvement … I always thought Springtime was the best. Which is it?

Fall is absolutely the best time of year—particularly in the Northeast. Ahlgren Landscaping specifically considers September to be your ideal lawn month. With regards to seeding this is especially TRUE since:

  1. In fall plantings from the nursery, there will likely be less weed competition, and
  2. Any young grass has two “cool” growing seasons before inevitably facing the extreme heat of Summer. This also applies to broadleaf weed control, since weeds are starting to store reserves for winter and herbicides tend to be more effective. Never attempt to seed and control weeds at the same time—in nearly all cases any herbicide will adversely affect the development of new and upcoming grass. With any Springtime plantings, it is best NOT to apply crabgrass controls AND seed a lawn at the same timemost pre-emergent chemicals also inhibit grass seed germination. Be sure to thoroughly read the label of any herbicide you plan on using!

From time to time I notice a huge flock of blackbirds on my lawn. Any idea why?

You just might have an infestation of sod webworms and these birds are all gathered for a buffet lunch. Take a walk on your lawn—if you notice small round holes in your lawn, that’s where the birds worked their beaks into your turf. Consider having a licensed applicator treat your lawn with an insecticide to rid the lawn of sod webworms. If you choose to do it yourself, please follow any/all label directions.


Our lawn looked great the first seven years—now it is starting to lose it’s luster … any idea why?

Many refer to the first seven years of a new lawn as the “honeymoon period.” In many instances, this is the time homeowners begin to notice differences. This is often related to thatch buildup at the base of the lawn blades. We recommend core-aerating your lawn at least once a year—that’s excellent preventive maintenance.


If I use a mulching mower will it produce thatch?

As a result of mowing, mulching clippings are usually an excellent idea because they provide valuable nutrients for your soil, helping your healthy grass thrive! “Thatch” is most commonly produced by heavy fertilization with nitrogen, however, there are some naturally occurring causes. NOTE: NEVER cut off more than 30% of any grass blade during any mowing—it’s not good for your turf’s health. Always be sure to mow often and particularly when the grass is dry.


My lawn has raised areas … it’s almost as if something is tunneling under the turf. Any idea what is causing it and how do I fix it?

These raised tunnels are referred to as “runs” and even after tamping or being packed down these “active” runs will be reopened. Most likely moles are tunneling through your soil looking for food. FYI: one mole alone can eat 40 pounds of worms and insects per year! To take action: the active runs are where you’ll focus your attempts at “trapping” moles with any of these traps. TRAPS: Consider either the harpoon, scissorjaw, or choker loop—check any/all labels for usage and safety precautions! Many experts feel trapping is the only method for effectively reducing a mole population. Over the years, effective “home remedy” mole control have included everything from Juicy Fruit gum … to half-buried Coke bottles … to chemical grub controls. We are aware of a few homeowners who have implemented battery-operated ultrasonic emitters buried several places around their landscapes, with fair results. Overall, Ahlgren Landscaping recommends “trapping” as your most effective option.


We installed some landscape lighting in the garden and have ongoing problems with the wires being cut by bed edging and digging activities. What can we do?

When you install landscape lighting we recommend 3 things:

  1. Bury any wires at least one foot (12-inches deep)—respect and check your local building codes for requirements.
  2. Put any wires in plastic conduits to protect them from sharp digging tools—you’ll want no future surprises!
  3. Draw a diagram of where all the wires are located for your future reference. REMEMBER WHERE YOU PUT IT! With this diagram, you’ll be able to show contractors where these wires are located.