From: klier@iscsvax.uni.edu
Newsgroups: rec.gardens
Subject: Re: Seeds
Date: 11 Dec 92 12:25:20 -0600
Distribution: na
Organization: University of Northern Iowa

In article <1g8b7jINNk2g@network.ucsd.edu>, mab@chem.ucsd.edu (Mary Ann Buckles) writes:
> 1.  Do all plants that have flowers produce seeds?
All gymnosperms (conifers) and all angiosperms are seed plants.  They are
all capable of producing seeds.  HOWEVER, if the plant breeders have
gotten ahold of the plant you're hoping to get seed from, or if the
plant is a natural hybrid, it may be sterile (i.e., not set viable seed).
Ferns, mosses, liverworts, fungi, etc., reproduce by spores.
> 
> 2.  After the petals drop off, are the seeds ripe or should they stay
>     on the stem awhile longer?
Petal abscission (dropping off) is just a sign that the flower has a)
been pollinated  or b) hasn't been pollinated but is now too old to 
accept pollen.  Seeds are formed from fertilized ovules, and take several
days to several weeks to several months to mature, depending on the species.

> 
> 3.  How do I know when a seed is ripe?
Seeds are generally fully ripe when the fruit starts to dry down or is
ready to fall or open.  Seed is usually viable _long_ before that time,
but may not give good germination.   A good way to collect your own seeds
is to put paper bags over developing fruits (or mesh bags if you've got
large seeds) and Just let the fruits ripen normally.  Or pick almost ripe
fruits and put them in a not-too-warm place to dry naturally.

> 
> 4.  People have spoken about drying seeds.  Why do you have to dry them?
>     Can't I just toss the seedpods out on the ground and hope they take?
You really only need to dry seed for storage.  You'll have the best luck
usually if you plant freshly harvested seeds.

You don't generally want to plant intact fruits (seedpods) because 
a) if you get a bunch of seedlings all coming up in the same place, you've
greatly lowered the chance of survival of ANY seedling   and b) many fruits
contain seed germination inhibitors that have to be removed before
the seeds will grow.

> 5.  I've heard of root powder or rooting hormone to encourage root growth.
>     Is there something like seed hormone to encourage seeds to sprout?
Nope.  In dry climates, though, you might want to consider adding a hydrogel
like "wassergel" or a gelatinized starch to the soil to hold moisture well
enough to get good seed germination.  Most seeding failures I see are due
to the fact that the seed starts to germinate, but the soil dries out
and the seed dies.

Seed collection and processing has an ENORMOUS amount of technical literature,
'way too much to summarize here.  But there are a couple of books you can
probably get from the library (or on interlibrary loan) that can give you
an excellent basic education on seed germination techniques.

"Park's Success with Seeds" is from the Geo. Park seed company, and is
aimed at techniques of starting seeds from packets and getting them ready to
transplant.  Good beginner's book.

Young and Young's "Collecting, processing and germinating seeds of wildland
plants" is a _fantastic_ book packed with all sorts of information about
growing native plants from seeds.  Although they mainly talk about woody
plants, the first chapters are devoted to the theory and seat-of-the-pants
techniques for seed processing.  Great stuff.  There's a new edition I
haven't seen yet, but even the first edition is loaded with good stuff.

If your slope is as fragile as you make it sound, you _might_ want to
consider having it hydroseeded.  A hydroseeder is one of those spray
gizmos you see planting new highway construction, spraying a mixture of
seeds, mulch, and water all held together with a "tackifier".  Keeps the
seeds on the hill and moist enough to get seedlings established.

Some large nurseries have hydroseeders-- if you find one, and you're willing
to accept a seed mixture they're using on a larger project, you might be able
to negotiate a reasonable price for them to come by and do your little
hill when they're done with the big project...

Kay Klier  Biology Dept  UNI

Newsgroups: rec.gardens