Answer: Replacing plantings will not limit fleas or ticks, with the possible exception of cutting back heavy underbrush to create a perimeter area around the home if for example you live in a wooded area.
Based on your description I would suggest you consult with your Cornell county extension as to the best way to handle an intensive flea and tick problem in your yard. They should be able to suggest cultural control strategies and if a chemical control is needed, would be able to tell you what to use and how/when is best to apply it for maximum results. Since insect killer (and weed killer) can be harmful to people and animals and the environment if misused, you do not want to use any more than absolutely necessary to correct any problems you may be having.
You may also want to use an insect repellent when you go outdoors as recommended by the Centers for Disease Control. Here is information from their web site.
Your veterinarian should also be able to suggest flea and tick control approaches for your pets, if you have any.
I hope this helps you with your landscaping this summer.
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