Srimathe Ramanujaya Namaha,
Namaskaram ‘G’ Swami a.k.a ‘Sundara Ramanuja Dasan’ Swami and Velukkudidasan Swami,
First of all, Tulsi Thayaar plant leaves to be plucked ONLY for Perumal purposes.
When we apply Tulsi leaves in Perumal Thirumanjanam vattil & on Thaligai samarpanam, then we consume Tulsi in thatTheertham or Thaligai as Perumal Prasadham.
In this case, we don’t need any ஓஷதம் as general Santana dharmis follow, since they don’t do Perumal Thirumanjanam, so they focus on body health by considering Tulsi Thayar as a Herb. But Sri Vaishnavaites consider Tulsi as “Thayar” and not as a “Herb”.
Anyway, Adiyen had heard with Acharya ThiruvAdi Bhalam and Velukkudi Swami’s Aasirvadham that:
Only when we follow a proper acharam (like after bath) , we should go near Tulsi plant
Before Plucking we should say to Tulsi Thayaar as:
“Pathram Tvam kShamasva
(Please forgive me for Plucking Leaves)”,
“Sri Keshava Priyayai Namaha“,
“Sri Govinda Priyayai Namaha“
While Plucking we should be chanting either:
“Godha Chathusloki” or
“Godha Stuthi” or
“Lakshmi Astotharam” or
Any Namaas of Thayar.
After Plucking we should say to Tulsi Thayar as:
“Devarirai Perumal Vishayathukkaga Azhaitthu Selgiraen. Devarirum Perumalum Sertthiyil adiyenai Anugrahikka vendum”
There are also rules when to pluck and when not to pluck Tulsi leaves.
Only Any dry leaves or dry stem needs to pruned for healthy growth, and while doing it the above sequence to be followed. Other than that Adiyen has not so far heard of general pruning on a healthy stem of Tulsi Plant. So Adiyen believe it should be avoided since we a Vaidehaas in general and Treat Tulsi plant as Thayar and not like ignorant elephants mazing around on plants.
Adiyen posted more details of Tulsi Thayar Mahimai from the upanyasams in the past as in below link and Velukkudi Sri Krishnan Swami’s Enpani #1062:
Adiyen (ElayaAlwar) Srinivasa (DhoddayAcharyar) Dasan