It's June. The weather is warming up. It's a nice time of year in New Jersey. Unfortunately, this also means that the spinach is feeling frisky.
Cold weather vegetables like spinach do something called "bolting" when the weather really starts warming up and sunlight fills more hours of every day. My spinach has started shooting up into long scraggly plants with small barbed leaves. They have also started developing something that may turn into flowers some day, that is, if I don't pull out all the unproductive spinach first and replace those plants with a warm weather substitute like amaranth.
My other cool weather vegetables (like lettuce) have yet to bolt. Not all of my spinach has bolted yet, either. At least I can plant it again later in the season for a fall crop.