MySQL 8.0

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select version();

version()

8.0.36

create table skus (id serial, plant_species_ids text);
insert into skus (plant_species_ids) values ('1,2,3,2,3,1'),('3,1'),(null);
create table plant_species (id serial, name text);
insert into plant_species (name) values ('Plant 1'),('Plant 2'),('Plant 3');

Records: 3  Duplicates: 0  Warnings: 0

Records: 3  Duplicates: 0  Warnings: 0

select skus.id, GROUP_CONCAT(plant_species.name SEPARATOR ', ') as plant_species_names
from skus
join json_table(concat('[',skus.plant_species_ids,']'), '$[*]' columns (id int path '$')) as species_ids
left join plant_species on plant_species.id=species_ids.id
group by skus.id

id
plant_species_names

1
Plant 1, Plant 2, Plant 3, Plant 2, Plant 3, Plant 1

2
Plant 3, Plant 1

id	plant_species_names
1	Plant 1, Plant 2, Plant 3, Plant 2, Plant 3, Plant 1
2	Plant 3, Plant 1