~ Margaret Atwood
I’ve been
experimenting again. And since it is time for many of us to get seeds started
for some fall vegetable crops I thought I’d give you another peat free option
for indoor seed starting.
Hydroponics is
the process of growing crops in water with no soil. Well known to those who
grow hydroponic is rock wool. Historically rock wool has been used for decades
in some European countries for housing insulation. Today it has been adapted
for commercial applications around the world to grow our vegetables in
greenhouses. Rock wool is a product of super heated rock until it sort of
explodes into fine filaments, kind of like cotton candy (candy floss), then is
formed into a usable material. At least that’s my loose translation of what it
is. You can get a more detailed explanation at http://grodan101.com/about-us.
Rock wool for seed
germination is formed into cubes. It is all natural and chemical free. Each
cube is wrapped in plastic which makes it easy to write your planting date and
seed variety on the side. It is said to be a biodegradable plastic, but I
prefer to remove it when I plant them into the soil, so the roots that emerge
out the sides are not hampered in any way. I doubt it biodegrades very quickly.
After all plastic is plastic and I don’t want it in my garden. Maybe someday
they will change it to a paper wrap. In my situation I don’t need it to be
wrapped at all but I suppose commercially the big growers do.
The manufacturer
states that rock wool is recyclable but, I think more likely only at the
commercial level of use rather than for the average home gardener. Since it is
made of rock it does not decompose so as we use a few each season they are more
likely to end up in our compost piles after we clean out our vegetable beds at
the end of harvest. Crumbling them up into smaller pieces as you find them, they
will provide a means of looser soil structure adding to your soil’s tilth, much
like stones or sand provide, helping drainage and bringing air down into the
soil.
Rock wool cubes
are a good choice for starting seedlings because of its air/water
transferability. There is little risk of rotting seeds from being too wet as
long as it is not sitting in water. I also think they are not so quick to dry
out like peat pellets do. I started this tomato Willamette
on March 16 and today it is growing and blooming beautifully in my garden.
If you study this
option on the internet, you’ll find lots of rules and do’s and don’ts. For
instance there is talk of initial Ph level adjusting, lemon juice remedies, and
some chat groups say you can’t transfer these into soil growth, etc. I didn’t
do any of that and I did plant this tomato into the soil and had no problem at
all. The only thing I did do prior to putting the seed into the cube is rinse
it well in running water. If you are used to using peat pellets, I used the
rock wool in the same way. I moistened it thoroughly first, inserted the seed,
kept it moist but not soggy wet and waited for the seed to do its thing. I’ve
used them on a heat mat or not, either way.
They cost a
little more per each than peat pellets or coir pellets. I didn’t really shop
around, I just went to my local hydroponics store for the sake of convenience
and time so you may find better prices. If you are looking for peat free
alternatives, I encourage you to experiment with rock wool cubes.
Cheers!
In Bloom in My Garden Today: Alyssum, Armeria
pseudarmeria latifolia ‘joystick mix’, Asiatic lily, Baptisia, Begonia
‘bonfire’, Bletilla pink, blueberries, Carnation, Daisy(white double), Daphne
caucasica, Digitalis grandiflora, Fuchsia, Gaillardia (blanket flower), Hardy
Geranium, Heuchera, Hosta, Kniphofia ‘little maid’, Iris, Lavender, Lobelia, Mullen
chaixii ‘Album’, Nepeta ‘six hills giant’ (catmint), Peas, Phygelius ‘new
sensation’ (cape fushia), Rose, Salvia, Sedum, Thyme, Tomato, Veronica ‘royal
candles’
Author’s photo
