Maximum Yield Australia/New Zealand March/April 2019 | Page 36

A
Caring
for
delicate
seedlings
Pre-Veg
by Grubbycup
When it comes to nurturing seedlings, gardeners
need to be careful given how fragile plants are
in the early development stage. Below are some
tips for growing healthy pre-veg seedlings.
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Maximum Yield
fter a seed has sprouted — but before it enters the
preadolescence of vigorous vegetative growth — plants
go through an oft-overlooked and frequently under-
appreciated seedling (pre-veg) stage. While the time spent
in this stage is usually limited to a week or two, it can be
fraught with opportunities for mistakes by unseasoned
growers and is less forgiving of errors than mature plants.
Anatomy of a Seedling
Inside a seed is a miniature, undeveloped plant, packaged
in a protective shell. A seed can survive without light or
additional moisture for months (sometimes years) in a state
of suspended animation under conditions that would kill the
same plant in any other life stage. Seeds should be kept in a
cool, dark environment away from moisture or high humidity
for long storage periods. Before sprouting, some seeds
require a moist period of lowered temperatures to simulate
winter in a process called stratification.
Seeds sprout when environmental conditions are
favourable and moisture enters through small holes in
the seed coat called micropyles. The moisture causes
the dehydrated plant to swell, and hydraulic pressure
bursts the seed coat from the inside. Food stored in the
endosperm feeds the sprout until it has developed the
ability to photosynthesize. The sprout sends down a root
(radicle) to draw in moisture and nutrients, then sends
up and unfurls a single seed leaf (cotyledon) in the case
of monocots (monocotyledonous plants), or a pair of seed
leaves in the case of dicots (dicotyledonous plants).
Plants with only these first seed leaves are commonly
called “sprouts.” Meristem cells are among the most
important to new development as they are undifferentiated
and can further develop into a variety of specialised cells
depending on location and need. The apical meristem at
the tip of the radius develops into the root system, while the
apical meristem between the seed leaves develops
into the first growth tip. Once the first true
leaves start to appear, the plant
is considered a seedling.