On 13/11/2013 20:54, Roger Tonkin wrote:
In article ,
says...
Perhaps this is another for a resurrected FAQ?
Sorry if it has been asked before. Not in my time on
the urg, which is why I asked it. Only one real reply
so far!
That makes me think that possibly there is quite a
turnover of lurkers/infrequent posters, so that such
questions will be repeated. May be I should have
googled first!
It is an age old dilemma how and when to lift dahlia tubers, it's almost
like how and when to prune roses.
"Don't lift till the plants have been cut back by the frost", but the
Dutch growers run a flail mower over the plants whilst they are still
growing and then lift a few days later, they don't have the worry about
soil on the tubers as their soil is almost sand so falls of easily.
If you can let the frost cut them back then lift, preferably when the
soil isn't mud,.
"Cut the stems off about 6 to 8 inches long and put the roots upside
down to drain". That's OK if you have a couple of dozen but if you have
hundreds it's not very practicable,
"Hose off all the soil from the tubers" OK if you have light soil but
with heavier soil you can skin the tubers.
In the US they leave the tubers in for 7 to 10 days to let the new eyes
develop a little then they lift, wash then split the tubers into
individual "Chicken Legs"(as we would call them) then wrap each one in
Saran wrap (cling film ) and store them in a multitude of ways, mostly
in frost free cellars, and on the Dahlia group it's normal for some to
bemoan the fact they have lost 20% of their tubers (or more) over winter.
Every year there is a long debate about how to treat and store the
tubers, do you dip in disinfectant, do you store them wrapped or un
wrapped, what temp. etc etc.
I lift my tubers when I can get on the ground, Remove what soil I can by
hand, trim the stems to 2 or 3 inches and pack then in a single layer in
Mushroom trays, (the ones like tomato trays). then stack the trays in a
frost free poly tunnel. In January I will go through the trays,
I use the same sort of trays, line the bottom with a single sheet of
paper,(radio times works well).
An inch or so of peat or compost to bed the tubers into, a variety to a
tray, (getting in all the tubers I can in each tray), at this point I
tease off more soil if there is any without damaging the tubers, and cut
off any damaged or soft parts, then I cover them with more compost,
(This helps insulate them should the frost get in). The compost is only
just moist.
The trays can either be stacked again 3 or 4 high or set out ready for
when you want to start them into growth, (Remember I am after cuttings
from them all)
My tubers are either first or 2nd year so are not to large..
When I start them into growth I water them having added a bit of washing
up liquid to the water as a wetting agent, this helps the dry compost
take up water and doesn't harm the plants.
After taking cuttings the tubers can be removed from the trays and
planted out when ready, or they can be potted prior to planting out.
Large tubers such as you get from Dahlia Imperialis are more difficult
owing to their size, but I treat them basically the same, though some
have to be potted up from lifting.
Last year D. Tenuicaulis was potted into a 25 litre tub and didn't die
back over winter so was still 6ft or so tall when I came back into growth.
Hope this helps.
David @ a now yet again wet side of Swansea bay.