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| Garden Diary
November 2009 |
| 12th
November: Cold
Sown Seeds
Many seeds need some cold before they
will germinate in spring so its time to think about sowing them now. Also
some seeds are best sown fresh so again get ready to sow now. We sow in
module trays with a Perspex cover and leave these outside all
winter. Fill the trays with multipurpose compost and tamp down to
ensure there are no air pockets. You can use John Innes seed compost but
we find this too variable in quality. Water very well and leave to drain.
Seeds we are sowing now include:
Angelica, Actaea, Cistus, Eryngium, Francoa, Lysimachia, Penstemon, Primula and Verbena.
Press the seed lightly into the compost.
We sow 2 - 3 seeds per module. Cover lightly with sifted compost and
label. |
15th
November: Cuttings
Last month I talked about cuttings from
the New World Salvias. This month I've been taking cuttings from hardy
types like the nemorosa varieties Caradonna, Amethyst and Lubecca. I
only had very short sections to use and I must say these all seem to have
rooted really quickly and easily with the only problem being a little
mildew on some of the cuttings from being in the warm humid atmosphere of
the propagator. These are already sending up new shoots from below the
compost surface which bodes well for forming a reasonable plantlet to go
through the winter. Next year I must try and get these done a bit
earlier.
By the way, Salvia nemorosa Amethyst
(right) is still flowering
well in the garden.
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17th
November: More Cuttings
Persicarias root rapidly and are good subjects for
cuttings if you have some greenhouse or cold frame space left. Varieties
of campanulata, microcephala, filiformis, neofiliformis and virginiana all
root readily at leaf axils on stem cuttings - microcephala rooting in about
3-4 days!. Unfortunately Red Dragon has plant breeders rights so we can't
propagate for sale. Amplexicaulis varieties don't seem to root this way
(unless you know otherwise) and need a small piece of rhizome attached. So
far I've multiplied single plants of the varieties Blackfield, Firedance
and Jo & Guidos Form this way, so next year I can plant out bigger
patches (not enough to warrant calling a "drift") of these novel
varieties.
Persicaria neofiliformis has lovely deep green leaves
with brown and maroon markings. The flowers (like those of P.virginiana
Painter's Palette) are described as "mouse tails" by Alan Bloom.
Indeed they do look rather like this in bud but they mature to have tiny
(really tiny) red flowers along them creating a most interesting effect at this time of
year. |
18th November:
Late Bloomers
Its a very mild autumn and a lot of
perennials are still blooming, some expected, some unexpected. The mild
weather is allowing some early flowering plants to have another go. Hardy
Salvias like Caradonna and Pusztaflamme are all starting to send up new
flower shoots - will they make it before the cold weather sets in?
Eryngium eburneum is flowering again, mixing ivory flower stems with the
brown dead heads we leave on over winter. Helenium Kupfersprudel (Dutch
form) is one its third or fourth flush of flower and I need to cut out the
old dead stems so we can enjoy these late blooms. Some
tender perennials like this Fuchsia fulgens hybrid are blooming better
than ever they did in the dry summer weather. This one really won't stand
any frost so I've taken cuttings (which I potted up today) which will go
on a cool bedroom window sill over winter. |
19th November:
Hanging on to Autumn
Autumn leaves are lovely and there are
few better than Acer davidii George Forrest (right). Golden leaves
contrast well with the coral red stems at this time of year. Its blowing a
gale today (as it has been all week) and the leaves are clinging on the
stems for dear life. Lets hope the winds subside soon so we can hang
on to autumn colour a bit longer.
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| 21st
November:
Winter pruning of perennials. Part 1. At
garden talks or through the website we get lots of people asking about
winter "pruning" of different perennials. For example today
someone visited the website with the question "winter pruning of
Veronica gentianoides". Its not something many books cover and I'm
not sure much research has been done into this. In this year's September
diary I covered "Preparing for Winter Interest" (24th
Sept 09) with my views on which plants to leave unpruned. Its a large
topic so I'll cover it off in several diary entries over the coming weeks.
But for part 1 lets cover Veronica gentianoides and other ground hugging
perennials. Ground huggers:
Why would be want to prune these? Well, firstly because they have spread
further than we want them and this becomes apparent when we cut back the
plants around them. For example I've just noticed that my Persicaria
affinis Superba has really
spread this year. However now is not a great time for me to cut it back
because I want to use the pieces I remove to make new plants and these may
not root if I do them now. So I'll wait until late February which for us
is when the soil start to warm up again. Ajuga
on the other hand seems to root quite readily so I am levering up rooted
runners and potting them up or moving to a new spot now. Some the ground
cover Campanulas
(e.g. punctata)
disappear below the ground over winter so leave these alone now and leave
a few dead flower stems on to show their position. We lifted and divided
our Corydalis
in late September / early October. I never tried doing them this late but
if you merely want to curtail the size of a clump you could do that now.
Centaurea can be cut back hard to the ground and it is a good time to find
any slugs and snails hiding in the leaves. Euphorbias
are a bit trickier. Ones like myrsinites or rigida that remain evergreen
are best left alone and any cutting back done in late winter to remove any
damaged or rotting stems (beware the sap!). If you have any of the really
invasive ones now might be a good time to try and get the roots out as
many send out new underground shoots over winter. With Geums,
just remove dead leaves and flower stems. I leave Saxifrages
until spring and see if there is any rot after winter. For Sedums
remove the dead flower stems - cut right back to the ground or just above
the new plantlets clustered round the stems. Veronica
gentianoides is one of those
plants where old leaves turn mushy in winter so it is best to remove
these. The trailing stems are covered with fresh root which suggests that
they could be transplanted now but we have had little luck with
transplants in pots in the open air over winter. Woody
Plants: Some of the plants we grow as perennials are woody plants and
may need pruning to improve structure, shape, flowering for next year.
There are (as far as I am aware) no defined methods of pruning like there
are for Roses, fruit trees and bushes, Wisteria or Clematis. In our garden
several woody "perennials" spring to mind. The Salvias
I leave be until late winter / early spring and then I cut them back to a
neat framework, taking out dead stems (by dead I don't mean leafless - if
the stem is still green inside its alive), badly shaped or broken ones.
Then I prune to give a good shape. I cut most of these woody Salvias back
quite hard because they will make plenty of new growth during the season.
I'd also leave Helianthemums
until spring and cut them back with secateurs or shears then. I don't
prune Cistus
into old, bare wood as they rarely resprout. But now is a good time to
take cuttings and this will serve to make the plant bush up in spring. Cut
off 3-4 inch long sections with a sharp knife and pot up in gritty
compost. Hydrangea
Annabelle is a woody shrub. When
cutting back cut just above a good bud if possible. You can leave it only
lightly pruned - remove dead flowers and damaged or badly placed stems.
For the largest flowers cut the stems back very hard - I used to cut back
to about 1ft tall. Nowadays I leave her a bit taller resulting in smaller
flowers but a better, self supporting plants. I cut back lightly leaving
some of this years growth on the plant. Note: other Hydrangeas are treated
differently but I have no experience of them. Coloured stem varieties of Cornus
are not pruned until late winter as we want to enjoy them through the
winter. The usual advice is to cut back very hard (say to 6in above the
ground) at this time. This assumes you want to keep them as a low growing
feature. I find vigorous ones like Midwinter
Fire respond well to this. My preference however is for lighter
pruning. I take out about a quarter to a third of the old, brown thick
stems right at ground level using loppers. I then remove poor twiggy stems
and those with any die-back (dead ends to the stems). I then cut back to
form a pleasing shape but not necessarily too low to the grown. Midwinter
Fire is best cut back fairly low. Cornus sibirica Alba with its bright red
stems I cut back to about 1 - 2ft above ground. With the black stemmed
Kesselringii I have been experimenting with leaving this largely unpruned
in height but just thinned out of old stems (see 17th
October 2009). I always cut back Anthemis
tinctoria it this time of year
as it stops the plants being too leggy next year. More
on pruning later. (see 8 December 2009)
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25th November:
Kniphofia trialWe received two
large boxes today stuffed full of Kniphofias returned to us by the RHS
after being loaned to them for their recently completed trial. Its
definitely not the right time to propagate Kniphofia so we are keeping our
fingers crossed about keeping them through winter. I've cleaned them up as
much as possible, removing dead or damaged leaves and cutting back the
fleshy roots as much as possible as these will only die and rot over
winter. I've planted them in fairly dry peaty composts and put them in
sheltered dry place. I am seriously considering packing them in dry peat
in a frost free garage over winter as I've noticed that pieces of
Kniphofia rhizome come out of the compost heap intact and sprouting in
spring. On the right is
Kniphofia Jonathan in our garden looking smouldering hot in front of the
icy Eryngium giganteum Silver Ghost. Jonathan performed very well in
the trial and we hope to have some for sale next year. |
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