If you don't have enough time to prepare in advance, you could try to apply for rehabilitation at the Canadian border port of entry. If you're applying for a "deemed rehabilitation," you should have had only one conviction and at least 10 years should have passed since you paid all the penalties, including any jail time, for your reckless driving conviction. In case you have no more than two convictions for reckless driving, you could take the "streamlined rehabilitation" route. At least five years should have passed since you paid all the penalties due for the conviction. The Canadian government will only consider rehabilitation if your reckless driving convictions did not involve any serious property damage, physical harm to anyone, or any kind of weapon.
If it's been more than five years since you were convicted for your reckless driving, you could also apply at a Canadian Consulate in the United States for approval of rehabilitation, in advance of your trip. This could be because you don't want to take your chances with the Canadian border laws or because you are not eligible to apply at the border. Here too, there is no guarantee that your application for rehabilitation will be approved.
If you are not eligible for any sort of rehabilitation, another option is to apply for a Canadian Temporary Resident Permit. This gives you special permission to enter Canada. You should apply for a Temporary Resident Permit at a Canadian Consulate in the United States. Keep in mind that there is a processing time, and processing fees, to get the permit. It will take a few months for the Canadian government to process this permit.
