Sowing Tips
These apply to all seeds other than vegetable or other seeds sown
directly outdoors in the soil.
Read the instructions on the
packet! OK I know this sounds obvious, but there are two common
mistakes why seeds don't do well. First of all they are sown at the
wrong temperature and secondly, they are sown at the wrong time of the
year. The packet will tell you about both of these.
Use clean seed trays or pots. Either brand new or that have been
washed and cleaned with bleach and then well rinsed. You don't have to
do this with every pot you grow a plant in, but I always do it for seeds
that may easily succumb to diseases that larger plants can shrug off.
Use new seed compost. Proper "seed" compost, not the
multi-purpose stuff that you can get everywhere. The difference that it
makes is remarkable, it's not just a marketing idea, it really does make
a big difference, both in the % germination you will get and also
in how well the seedlings develop. I know it costs more, but probably
the same or less than some packets of seed and you don't need to
completely fill the tray as you'll be pricking the seedlings out before
they get very big anyway. Soil-less seed compost is better than John
Innes.
As a rule of thumb sow seeds at the depth of their own diameter. For
large seeds, they can be pushed into the seed compost, for smaller ones,
I sprinkle them over the surface and then sprinkle over the seeds with
fine sieved seed compost (I rub it slowly between my hands
and let it fall).
Don't sow seeds too thickly, it will make pricking them out more
difficult later on and may also encourage fungal diseases to take hold.
"Damping off", a fungal disease is the biggest potential
problem with raising seeds. All seeds sown indoors are best treated
with a copper-based fungicide or traditional "Cheshunt
Compound" at sowing time.
Once sown, water the seeds from below, immerse the pot or tray in a
container full of water. I find the wheelbarrow is ideal for this (mine
doesn't leak) if I've got lots to do as it's wide, shallow and holds a
lot of water.
Never place seeds or young seedlings in direct sunlight. They should
be somewhere bright, but not receive direct sun for even a small part of
the day. Once they've grown on a little (a week or so), they can be
placed in the sun as long as they are varieties that like sun of course.
Cover newly sown seeds with a pane of glass, or even some clear plastic
food wrap. Once the seeds have started to germinate, remove this
completely or it may encourage disease. Some seeds will germinate better
in the dark, others in the light, again read the packet for
instructions.
Once seeds have germinated, they need to "pricked out", that
is taken out of their seed tray and given a bit more space in compost
with more nutrients (enter "general purpose" compost stage
left). Don't be in too much of a hurry to do this, sometimes it is
recommended to move them when they have "two good leaves". It
depends on the plants and also how delicate you can be or have the time
to be. Don't leave them very long however. Prick out 12 to 15 to a seed
tray, this time more deeply filled with compost.
Storage - seeds should be stored
in their unopened packet where possible in a plastic bag and in a
plastic Tupperware or similar container at the bottom of a domestic
fridge. Many seeds will last for a few years in these conditions as
opposed to just a few weeks or months in warm moist conditions.
Thompson
and Morgan germination guide
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