Garden spiders are harmless and fun to watch. They are superb architects and play an important part in controlling insect populations. Black and yellow garden spiders are easy to find. They are common in gardens, fields and urban backyards. This spider is big, with fully-grown females reaching an inch or more in length. The spider commonly weaves a characteristic zig-zag band in it’s web and eats a variety of insects, including grasshoppers and katydids.