Colorado appears to be giving up on its effort to crack down on medical marijuana growers using a legal loophole to grow high numbers of pot plants without the kind of oversight faced by commercial growers. Medical marijuana caregivers cheered the news yesterday. Earlier this month the state Health Department sent letters to about 2,300 doctors who have recommended medical marijuana. The letters sought medical justification for recommending more than six plants to any patient. The Health Department questioned the medical necessity for more than six pot plants per marijuana patient. But a lawyer for the state says the Health Department won’t pursue the matter. The Health Department did not immediately respond to questions about the change. A proposed bill to end “medical necessity” marijuana waivers has not been introduced.