Yes, they have a fee to do so and your dog must be on a leash
Yes, with due diligence.
Yes on a non retractable leash and it does cost $5 to get the dog in
You can but their is a fee and their are requirements (like rabies vaccination) and restrictions. https://www.garvangardens.org/visitor-guide/dog-policy.aspx
When we were there in May, we saw several people with dogs.
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