Monday, January 30, 2012

New zone map unveiled

The USDA has unveiled it's new hardiness zone map, and it's now interactive!  No more staring at a tiny map and guessing, especially when you are near the border between 2 zones.  Enter your zip-code and voila!  You can also zoom in.  Nice and handy.  And based on 30 year data the trend is slightly warmer zones, which I agree with.

Saturday, January 14, 2012

Fargesia

Fargesia nitida in January
People are always amazed that we can grow bamboo in Wisconsin.  The gardeners who know we can grow bamboo often seem amazed that we can grow some that don't have plans for world domination.  The various species of Fargesia are well behaved, unlike so many other hardy bamboos that are readily available.

In general Fargesia prefer partial shade and organic rich well drained soils.  They are slow growing, taking quite some time to reach mature sizes.  In cold areas they will not likely reach their full size, 1/2 to 3/4 size is likely.  With proper siting many will over-winter in zone 5 with few problems.  Keeping them out of strong winter wind is important.  I've grown 2 species of Fargesia so far.

I planted Fargesia nitida in 2003.  It started as a 1 gallon pot and has since grown into a 7' tall x 4' wide specimen.  Typically bamboo are semi-evergreen, but in colder climates they commonly drop their leaves in all but the mildest of winters.  They will usually leaf out again from the old culms, but it may take some time so be patient.  Mine has leafed out as late as mid-June, but usually is green by the end of May.  If it doesn't leaf out by mid-June, you may need to cut it back to the ground.  This happened in 2007 to all of the Fargesia that I'm aware of in the area.  For some reason I couldn't figure out they died back to ground level.  The winter wasn't terribly cold or windy and we had adequate snow cover.  After being cut back, they resumed regular growth and were 30" by the end of the summer.  Fargesia nitida is hardy to zone 4a, and can grow to 12' tall with a spread that is slightly less, probably 8'.

Fargesia dracocephala 'Rufa' has become quite common in the nursery industry, and is somewhat similar to F. nitida.  As a young plant it appears stocky, full and cascading; a habit it maintains into maturity although it does become more upright as it ages.  It will be smaller in stature than F. nitida at only 8' or so, but will be more full to the base and seems like it will be wider.  'Rufa' has also been more difficult to grow for me, though there are definitely differences in soil and exposure.  Mine has struggled, dwindling for a couple of years but seems like it is making a comeback.  This one is slightly less hardy, probably to zone 5.

Currently on my list of must haves:  F. dracocephala 'White Dragon' - a variegated clumping bamboo!  Now to find a spot for it...