First mowing of 2016

A mild winter and warmer than average March caused the grass to green up early in our yard, but since April has been considerably cooler than average, we were able to delay the first mowing until April 13.  As usual, the back yard was probably too long, while the front yard was barely long enough to reach the mower blades.  Historically, the date this year was on the early side of the median, although almost 3 weeks later than the earliest.  Which got me thinking, "I wonder what determines how fast the grass grows in the spring?"  I don't have good data for rainfall in our yard, but since I do have approximate temperature data, I thought growing degree days might be worth investigating. Growing degree days (GDD) are calculated by the number of degrees Fahrenheit the mean daily temperature exceeds 50°F.  So a day in which the mean temperature is 56°F would produce 6 GDD.

In this chart, the green bars represent the first mowing date for each year, while the red line marks the cumulative GDD up until the day I mowed.  Initially I thought the number of GDD might be constant across the data set, implying that the grass is ready to be cut once it has received the right amount of warm weather.  Since an earlier date would probably require more GDD than a later date, it seemed the date and GDD were probably inversely related, hence the degree day data are inverted on the chart.  Although the correlation isn't horrible, the inconsistency across the data set convinced me something was missing. Maybe rainfall data? Maybe something else?

Does the date data correlate better to Heating Degree Days (HDD)? HDD are similar to GDD except they represent the magnitude of the mean temperature below 65°F.  A warm spring would have fewer HDD and presumably an earlier first mowing, while a cold spring would accumulate more HDD before the first mowing, presumably resulting in a later first mow. As you can see, the correlation is pretty close. The HDD data is limited to the days between February 1 and the mowing day, although when the month of January was also included, the correlation looked very similar. The variation from month to month is still unexplained, for instance, why wasn't mowing required earlier in 2009, 2011, and 2016 as the HDD data would seem to suggest?

Those are questions for another day (or another blogger), and even though I think we can correlate HDD to the first mowing date, I'm at a loss to see a method to predict the first mowing date. I guess that gives me something else to ponder until next spring.

First mowing of 2015

Spring growth was pretty minimal this year until about a week ago. Suddenly, trees are flowering, budding, or leafing out, and the grass is not only green, but long enough to cut. Although the yard could have waited a few more days for the first cutting, the weather on April 18 was well suited to mowing. It was evidently well suited to farming also as farmer neighbors in the two fields adjacent to our property were both out working, one planting corn in the field to the north, and the other performing a second fine tilling operation in preparation for planting in the field to the west. Although I'd seen tilling in other fields in the area earlier in the season, I hadn't noticed much planting until the 18th.

Time will tell how many more times we'll mow before the season is over, and I'm sure I'll tire of the experience at least once before next winter, but for now I'm glad to see green growth again!

First mowing of the year

I tried to push the mowing off until May this year, but some parts of the yard were getting unruly, and all the neighbors had already mowed, so the pressure to conform was just too great.  Our long, cold winter made many of us think spring would never arrive, but this spring has been pretty mild and pleasant, all things considered, which also means the grass eventually needs attention.

First full mowing of 2013

No, today was not my first mowing day of the year.  The picture above was taken on April 24, which is probably the latest I've pushed off mowing since we moved here in 2007.  I don't recall when we started mowing in 2008, but 2009 was kicked off on April 22, which was my previous latest start.  My post from March 26 this year showed how winter tenaciously hung on this year, and at that time I thought I may be able to push the mowing off until May.  Alas, maybe next year.

What a difference a year makes

A year ago, on March 24, I completed our lawn's first mowing of the season and felt like summer had arrived early.  This year, on March 24, we received 8 inches of snow.  I'm confident summer has not arrived yet.

This photo was taken after two days of melting and it should be obvious that the grass is a long way from its first cutting this season.  In fact, the grass is looking as dormant as it was in January.

On the bright side, the spring yard work looks like it can wait for a few more days.

First mowing of the year

Exceptionally warm weather over most of the last two weeks has convinced all our plants that spring (or summer) arrived early.  One could even argue that our unseasonably warm weather goes all the way back to last November.  Last spring, the mower didn't see use until April 20.  This year, the grass was unruly four weeks earlier, and it looks much better now that we've taken dominion over it once again.  Visiting every inch of the yard is also a good way to remind oneself of all the yard projects that are now available for tackling after being conveniently ignored all winter.  Ready or not, the mowing season has begun!

First mowing of the year

Two weeks ago, I thought the mowing season couldn't be pushed off any longer. A good bit of cooler weather since then seems to have halted the grass growth, but with lots of rain in the forecast, today looked like one of the few dry opportunities. The mowing season is starting 13 days later than last year, but two days earlier than in 2009 (the grass piles in the photo above suggest I waited too long this time). Coincidently, the first mowing day for all three years fell on a Wednesday. Although the cut grass is pleasant to look at, it looks like we're committed to tending to it for another 6 months.

First mowing of the year

Two weeks earlier than last year, but maybe that's what happens when the temperature peaks out above 80°F several days in the first week of April. Part of me wishes I could put this off for another 6 months.

First mowing of the year