In most places, pest termites are native animals, part of the wildlife and while they are allowed to be killed, chances are that there are that will just keep arriving. In parts of the Eastern USA, you can have upwards of 25 separate Reticulitermes colonies working a garden.
Keeping termites in the garden largely means leaving them alone. Keeping those termites out of you house can be harder. Subterranean pest termites, particularly some species of Coptotermes and Reticulitermes, should not be encouraged near structures. To be sure, you need to know what species you have and how much of a risk they are in your area. Your specialist termite inspector can help you there.
If your garden has dampwood termites, these are much less likely to enter a well-built, properly drained building than the tunnel-happy subterranean termites. If you live in an area of known drywood termite hazard, then you’ll be slightly increasing your risks if you leave known drywood colonies alone.
Keeping the subterranean termites from finding the house is best done by keeping things dry and inspectable. See my Avoid page.
Things will be easier if your house has an effective termite management system in place, especially proper long-life physical barrier components (which don’t rely on a chemical deterrent). If your house has soil poison (‘termiticide’), then the non-repellent poisons (like chlorantraniliprole, fipronil and imidacloprid) may kill the subterranean termites in the garden while the repellent termiticides (such as bifenthrin and other pyrethroids) will usually just drive them away from the poisoned soil, leaving the colonies intact.
In any case, you’ll still need to have a proper inspection done (in most areas that means not less than once a year) to have a good chance of finding any incursion before serious damage can happen.