Turfgrass Follies

Although gardening has been described as the slowest of the performing arts, lawns seem to revive overnight.  Seeing that blanket of soft green under the still-dormant oaks and just budding red maples does the soul good.  But look a little closer and it’s apparent the lawn could use some work.

Snowplows, snowblowers and cars running off the driveway create ugly bare spots.  Unfortunately, getting grass seed to germinate in spring can be tricky, since soils remain chilly.  Perennial ryegrass is the species to choose, because it germinates much faster than fescues or ryegrasses.  Putting ¼ inch of fine, dark-colored compost on top of the seed, or covering the seeded patch with vegetable-garden rowcover fabric, can hasten germination significantly.  A special lawn starter fertilizer can also help. 

Early spring is also soil-testing season.  When people see moss in a lawn, a good number of them rather inexplicably reach for a bag of lime.  I apparently missed it, but sometime in everyone’s American grade school curriculum a teacher intoned, “Moss in your lawn means that the soil is acidic,” and the statement is taken as gospel.  Sorry, sir, but after 30 years of soil testing, I know this just isn’t true.  Moss can grow on soils with a high pH, and adding lime to them will only make the situation worse.  Just this week a gentleman brought in a moss/soil sample and the pH turned out to be 8.0, quite alkaline.  We told him to look for a big bag of sulfur (to lower the pH), and start spreading.

So why the moss?  Moss is a poor competitor for a vigorously growing lawn, so there must be reasons why the lawn, or even weeds, aren’t thriving.  Perhaps it is too shady; grasses aren’t lovers of life in the dark.  There is a very good chance the soil is low in nutrients, including one or more of the big three – nitrogen, phosphorous, and potassium.  Maybe damage from grubs, chinch bugs, fungal diseases and drought has so weakened the lawn that very little desirable grass remains.  Without a good population of Kentucky bluegrass, the most vigorous spreading grass, a lawn doesn’t have the ability to fix the damage that happens to it.  A little fertilizer and generous overseeding often goes a long way. 

Another springtime rite-of-passage is raking.  Websites confidently recommend raking your lawn in spring for any number of reasons, but there is a dirty little secret they don’t know about:  raking activates weed seeds.  Take broadleaf plantain, Plantago major.  Its seeds can remain viable in the soil for up to sixty years, which means your grandparents broadleaf plantain can come back to haunt you.  However, plantain seeds need light to germinate, so if they are buried beneath even a particle of soil, they stay dormant.  Pity the fools who go out with their rakes, unwittingly scratch up the ground, and give an entire colony of plantain seeds the green light to germinate.  So, put down the rake, and go ride your bike or fly a kite.