Commonly
known as tagasaste or tree lucern, Cytisus
proliferus is well known in Australia and New Zealand. It is a small
leguminous tree providing fantastically nutritious forage (up to 30% protein,
dry weight), but also useful for firewood, as a wind-break, and a soil-builder. It is drought-tolerant, with roots are
capable of extending 10 metres down to reach water and nutrients inaccessible
to most plants. It can withstand
temperatures from -9 to 50˚C, so suited to vast swathes of country in both
hemispheres. Given that it is native to
the Canary Islands, and would probably be as useful in much of the Iberian
peninsula as it is in the southern hemisphere, it is oddly unknown in
Spain. It was a Spaniard, Dr Perez, who
in 1870 tried unsuccessfully to get the Spanish authorities interested in its
potential outside the Canarias. But it
found its way to Kew, and from there to the Southern hemisphere. The rest is history.
That was
getting on for a century and a half ago, and I have not managed to source seeds
of this plant anywhere; a google search in Spanish only comes up with seeds in
Argentina and Uruguay. Last year I got
some seed from Australia, which came with a little bag of inoculant to supply
the seeds with rhizobacteria; without that the plant would have to make do with
whatever rhizobacteria are present in the soil, which it may or may not be able
to utilize.
Getting
these shiny, black little seeds to germinate requires a bit of tough love. The notes which Green Harvest supplied with
the seeds suggest boiling or scarifying the seed, then soaking it. I tried both techniques, the scarifying by
rubbing the seeds between sandpaper, and had a more or less equal germination
rate, which was not very high. I had
gone to the trouble of sourcing some sandy soil from a garden center to get
these plants started and that, it seems, was a mistake. All the tagasaste which germinated, as well
as some pigeon pea, shriveled and died within a few weeks. Meanwhile, a citrus and a sapote potted up in
this stuff grew like crazy, so I come to the conclusion that this soil
contained a not insignificant quantity of chemical fertilizer and was just too
much for those tough legumes. I had
started late on the seeding, and by this time it was July and I figured I’d
missed the window for getting them started last year. So, 2015 and a new lot of seed and inoculant,
let’s have another go. This time I’m
using soil from the ground, I reckon it’s quite free-draining enough, mixed
with a bit of leaf compost. As the
brilliant Angelo Eliades writes in deepgreenpermaculture.com (check it out if
you’re interested in what can be done in a tiny Melbourne back yard), people have
been growing plants from seed way before bagged potting compost was
around. Time I stopped using that stuff
too.