To check for null value, you can add codes while retrieving data from database in query.
You can do like...
SELECT ISNULL(PlantName, '') as PlantName,
ISNULL(TradeName, '') as TradeName,
ISNULL(Synonyms, '') as Synonyms,
ISNULL(uses, '') as uses,
WHERE PlantId = @PlantId
So, ISNULL checks the first parameter (ex. PlantName) and if it is NULL, then it will return the second parameter, which is blank in this case ('').
Then after getting the values from the DB u can show the same...
Happy coding... :)