Hi DorsetBrit,
I recently had a landscape gardener approved for a Subclass 457 and my understanding is that at the moment there is a shortage of good landscape gardeners in Australia. So whilst the permanent skilled migration is a more secure option than the temporary Subclass 457, and doesn't need an employer, it may not hurt to investigate employment opportunities for yourself also.
Kind regards,
Kylie Maxwell
MARN: 1387166
International Organisation for Migration (IOM)
http://www.iomausmigrationservices.org