Rubromarginata is not growing

[aworldnervelink]

Two years ago I planted 12 rubromarginata plants in my back yard. I was hoping to form a view screen between myself and a neighbor. This is supposedly one of the most aggressive species so I was expecting great things (everyone told me I was crazy for planting it). We are now into the third season and the plants have done almost nothing - they struggle to grow to 6' each year. I am located in New Hampshire, on the edge of zone 4, so it is a cold location. However, our winters have not been that bad and our summers are very warm. The location also has abundant water, at the low end of a long gentle slope and near a stream. The worst thing I can see is that the plants are competing with a lot of weeds - I expected the bamboo to outgrow the competition. Any ideas what might be wrong, and how I can help the bamboo? Thanks!

[dependable]

It would probably like some fertilizer. A slow release grass fertilizer like Blue Seal Safe & Simple works well.

Zone 4 is pretty cold, but it got to 0 f a couple times last winter here, and my rubro is one my only bamboos that up sized and had no damage. It is in sheltered spot.

[oobmab]

Same here. I cut down some trees to give mine more sunlight, and it seems to be responding. New shoots, even later in the summer. Hopeful for next year.

Don't know how practical it is for your location, but pee works really well for fertilizer. Some of my treated phyllostachys plants have 9" long leaves, 1.5" wide; huge. Even the Rubro is putting out larger than normal leaves.

[jd.]

This is supposedly one of the most aggressive species so I was expecting great things (everyone told me I was crazy for planting it).

' might as well accept it. Count yourself as an intrepid member of bamboo growers in climate zone denial.

I am located in New Hampshire, on the edge of zone 4, so it is a cold location.

Here in zone 5, a rubromarginata with no special treatment only grows about 6 feet tall year after year. Despite not getting much taller, it does grow thicker each year.
That said, this rubromarginata is often protected by snow during the winter months which makes a difference in the colder winters.

The worst thing I can see is that the plants are competing with a lot of weeds - I expected the bamboo to outgrow the competition.

I do notice that a bamboo that grows taller and thicker with a few years of natural bamboo leaf mulch does well at keeping many weeds down. However, a bamboo may take several seasons of good growth to get to that size and winter damage can prevent a bamboo from ever growing very tall.

Any ideas what might be wrong, and how I can help the bamboo? Thanks!

In a location with marginal winters, good summer conditions become more critical for growth and survival. One thing you can do now is to pull out the weeds and lay down some organic mulch to reduce weed growth and boost soil moisture and fertility.

[needmore]

I don't know the length of your growing season, mine I think of in terms of frost dates early April to mid October is generally frost free here and we warm up fast, surely your ground stays cold longer being farther north. My bamboo starts shooting in late march and is done by mid may. Rubro is a late shooter here and I would expect that it is even later for you, or will become later after four years or so. Thus, it has a shorter growing season which might explain in part why yours has not spread much. Earlier shooters such as the aureosulcata clan might have been a much better choice and they are hardier than rubro.

[Iowaboo]

That species has never done good for me. It is considered one of the cold hardier ones, but it shoots later than others and that is a problem if there is any winter damage.

I've have had many different species of bamboo for 10 growing seasons now, last winter was the worst, 99% bamboo rhizomes dead, what species had a few rhizomes survive and come back ? I will have to check my other rubro plot, but think all of that species is dead now. In conclusion, find something else to screen in your climate, all it takes is one bad winter to destroy it all because of the shallow root system.

[Matt in TN]

We got down to eight below zero last winter and my Rubro is the only thing that thrived. I'm in a completely different zone of course, but it's 30' tall and will eat dogs if they stray too close.