Where do you live and what's your Zone?

Did you get recent rains and have some warmer than normal weather?

Thanks for the replies chaps!

I'm in North West UK, so it's not exactly warm! We have had some recent rains, and the temperature hasn't been as cold as it should be for this time of year. Could that explain it?

The shoots have grown really quickly and seem pretty strong and healthy.

I would guess that is what happened...warmer than usual weather and good moisture.

It will happen to me here sometimes. Tonight is out first really cold spell for this year and most trees still have their leaves and grass is green, and I have some bamboos with young growing shoots, but they probably will not make the Winter except for some of the clumping bamboo shoots.

Kt

Thank you again Kt. I also sprinkled a small amount of chicken manure around them, maybe a month ago, only later learning that it was somewhat too late in the season to be effective. Maybe that has contributed?

Another question I have, if you don't mind, is regarding the diameter of the shoots. Do successive years get thicker?

Yes, any type of fertilizer can contribute to early shooting but I have fertilized at all times of the year, or when I have manure available.

The new shoots, under good conditions, will get larger each successive season until they reach their largest size in your area and for the conditions they are growing in.

If you have a dry year and the bamboo does not get a lot of water for example, the bamboo may not put up larger shoots. Also, a confined running bamboo will only reach a certain size inside of a barrier as opposed to a bamboo growing freely in an uncontained area. My henon only gets about 1 1/2 inches thick inside of my barrier, but along the creek where I have it growing, it gets much larger.

The listed bamboo size such as by the ABS may not be the size that your bamboo will get. For example, aurea is listed to grow to 27' and 1.8" but here it gets 33' and over 2" in diameter, but most times the listed size is larger than what you will see. Most bamboos I grow never reach their listed sizes, probably due to less than optimal conditions for that species.

Kt