Horticulture
A horticulturalist is a specialist in gardening. A handyman is a person that may do various gardening and landscape chores.
A specialist in gardening or landscaping is who you hire to do the job. They can be self taught, a Master Gardener, certified nurseryman, horticulturist, landscape engineer, or combination of any of these.
Horticulturalist.
trowel
Horticulture.
reimbursement specialist
reimbursement specialist
rake
Because a specialist has the letters DDS after his name
There are a lot of websites that have got great ideas on organic gardening. To name a few, one could try websites such as Organic Gardening, Garden Organic and The Daily Green.
The type and availability of duckweed killer will depend on your location. It can purchased online, from local gardening centers or fish specialist stores.
Proctologist