There are a number of flowers you can grow that will not only attract bees to help with pollination but also are deterrents for other insects such as green flies and certain aphids and those flowers are marigolds. They come in a variety of colors and will work wonders for your garden. A perimeter of them will do the trick.
You can also plant sunflowers to attract bees (I like the Giant sunflowers that can grow as much as ten feet tall). Now of course you don't want to over do it. Bees can and will sting if they feel threatened so plant enough to attract for the amount of bees you will need based on the size of your garden.
Butterflies are another species of creature that can be extremely beneficial to the home vegetable gardener. Lavender works well for butterflies, but if you really want to attract them, plant a butterfly bush nearby.
Round out your healthy garden by attracting some ladybugs by planting some fennel. Ladybugs feed on aphids which could be extremely harmful to your plants.
