YIKES! String Broke. Tomatoes on Ground

[PaulTandberg]

I went out to my little poly greenhouse to check on my tomatoes and two were on the ground. The string I had been clipping them to broke.

Tomato #1 was a fully laden Damsel about 6' tall. Tomato #2 was a fully laden Chef's Choice Bi-Color also about 6' tall.

- The string was from a roll of string I purchased from Johnny's along with a bag of those plastic clips used for clipping the tomato vine to the string. The string and clips were packaged together and intended to work together well with each other.

- The string the tomatoes were clipped to was in it's second year of use.

- The string, in each case, broke where it was wrapped around the top tube of the greenhouse frame. The string was directly beneath and in tight contact with the poly, pinched between the steel tube and the poly top the tube was supporting. It has been sunny and hot lately.

Last year I had no trouble with a single strand of string supporting large, laden vines. Was I lucky? Is the string meant to be replaced each year? Could the string, trapped between the steel pole and the poly top, have succumbed to the heat? Or friction? Are you supposed to use multiple strings for large fruit-laden plants? (the youtubes I watched on "string and clip" support systems only used one, or so I recall, maybe I wasn't looking carefully).

I attached fresh string to a couple anchor clips on the plants and hoisted them back up (like I was hoisting a mast of a ship). They appear unharmed by the experience, for the most part.

I now have three strings assigned to supporting each plant at various points. And I have assigned additional support strings to the plants that didn't collapse. Next year I may attach a sturdy ring/loop thingie to the tube and attach the string to that.

Where did I go wrong? What should I know? I sure didn't expect this.