Seed sowing

John Lonsdale
Thu, 21 Nov 2002 06:51:26 PST
Several folks have commented on the recent TOW that they bear in mind the
plants natural habitat/climate when choosing composts and conditions for
seed sowing and germination.  I would strongly agree that this is vital when
considering growing conditions for plants and bulbs once they have become
established (in this case established can mean as soon as you move them from
their seed pots).  However, I find it is less important when considering
seed sowing media, and all of my seeds are sown on the same medium and given
the same very basic treatment.  This standardization saves a huge amount of
time and also makes it easier to grow the bulbs on as they are all in the
same size pots and compost, hence they dry out at roughly the same rate.
The ability to water correctly is probably the hardest skill to acquire and
responsible for most losses.  The absolute requirement is good drainage,
after this it probably doesn't make a lot of difference what is in the
compost as long as it is amenable to the plants and you are comfortable with
its properties when it comes to watering and feeding.

I use 3 1/2" or 4 1/2" Kordlok pots for bulbs because of their extra depth,
and fill them to within 1/2" of the rim with a 5050 mixture of BioComp BC5
compost (coarse grade composted peanut hulls and bark) and supercoarse
perlite.  Seeds are sown as soon as available on the surface then the pot
filled to rim with starter grade granite grit (poultry grit).  After
watering overhead they go onto the floor of my small greenhouse until they
germinate - they will get to or just below 32F but won't freeze through, the
latter is detrimental even to emerging seedlings of 'hardy' bulbs.  After
germination they come into my bigger greenhouse where they won't get below
around 40F but they get excellent light and ventilation.  Most bulbs stay in
their seed pots for a minimum of two years.  Most waterings, except the
first few that wake them up in the fall, include weak fertilizer from an
in-line feeder (EZGrow).  Most of my bulbs are summer dormant so they go to
sleep usually in May, after which point they are kept completely dry until
they are woken up in mid-September when we have cooled down a little.  Newly
germinated seedlings are kept growing as long as possible their first year
by keeping as cool as possible, often with more shade than they would get
when mature.  Watering any sooner than mid-September (here on the east
coast) risks significant root and bulb rot.

I never soak seeds or pre-/post-treat in any way and am very satisfied with
the germination rates I get.  Sowing around 400 pots a year usually means I
get 300 pots germinated, and once you get into the swing there are so many
new flowers each year that it really doesn't matter if germination could
have been hurried along a little sooner.  Pre-treatments certainly can and
do work but I figure their main merit is in commercial growing when very
rapid and uniform germination is an absolute requirement.  I grow a very
wide variety of bulbs from seed and don't have any particular genera that
just flatly refuse to behave, although Juno and Onco irises can be delayed
and sporadic germinators.  Colchicum can also be frustrating and, with the
exception of kesselringii, seem to give relatively poor results.

I also have a question.  Should seed of things like Crocus be allowed to dry
out during the summer if they don't germinate the first season (usually
because sown too late) ?  I tend to keep all my seed pots moist year-round
but always find in the fall a fairly small proportion of pots in which the
seeds have rotted during the summer.  I never know whether this is because
the seed was too wet (and hot) or whether it was no good in the first place.
Older seed is more prone to this, and the fact that most pots are just fine
would make me think it is better to keep them moist.  The danger of keeping
them dry for several months would be that seed of plants like Trilliums,
Erythroniums and other such things would become inviable or inhibited
further from germination.

As an aside, I have just had a pot full of Fritillaria striata seed
germinate.  This seems very early but  may fit in with its life cycle in
habitat.  Can anyone comment please ?



Dr John T Lonsdale
407 Edgewood Drive,
Exton, Pennsylvania 19341,  USA

Phone 610 594 9232
Fax 801 327 1266

Visit "Edgewood" - The Lonsdale Garden at http//

Zone 6b

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