Planting 

Tobacco is annual plant, starts from seed every year, and it takes min 7 months to grow from seed to maturity.

Start seeds indoors about 12-15 weeks before the last expected Spring frost. For example, if you plan to transplant tobacco seedlings to the garden on June 1, then start them indoors mid  February. That is you will harvest tobacco plants in September. Remember that the first Fall frost below -5C will kill the plant and make it unusable for smoking. If you normally have first frost in your area in September, then plan to start seeds indoor even earlier than mid February.

Tobacco seeds are extremely small, but they grow into large plants.  Soil should contain nitrates, phosphorus and potassium.Sprinkle seeds on top of the potting soil in the container. Do not press them down and do not cover seeds with soil. Spray them with water, cover with clear transparent poly and put container on the sunny warm spot at room temperature. Germination will start in 6-14 days.

When seedlings show first true leaves, they are ready to be transplanted to bigger container. Keep them in warm, sunny place and water regularly.
Seedlings are ready to be transplanted into the garden when they are 6+ inches high. Make sure all spring frost are past then plant your seedlings into the sunny spot in your garden. Space them at least 2 feet in a row and 3 feet between rows.  Add some manure and ashes from fireplace and work it well into the soil. General purpose fertilizer can be added to the soil in the amount according to the label on the package.

 Caring for growing plants 

Freshly transplanted plants are very fragile and need couple days to settle. Leaves may visibly wilt, but it is normal. Transplanting on a cloudy day will help them to adopt more quickly to new environment. Water them daily during first week , or until leaves get strong again, after that plants require watering once a week or when soil is too dry.

Later in the season the plants will need to be "topped", which means cutting off the flower clusters before they open. Flowering clusters suck up a lot of energy from the plant, and it stops growing leaves. Auxiliary buds will then develop at the leaf base - they need to be broken off by hand. Make sure that your plant has one large leaf in each leaf base, and remove all small auxiliary leaves and buds.
Do not use any chemical insecticide, as the plant will pick them up and store in leaves. You do not want to smoke that !!
Also avoid to use soapy water as pesticide, because your tobacco will most definitely taste like soap.

Close to end of July when your plants are already mature and tall, you may experience that aphids inhabit your plants. They are usually harmless for your plants, but if you want to clear them off, then just wash your plants periodically with garden hose - it will wash them off to the ground, they cannot climb back again.

More harmful are the leaf-grinder such as caterpillars - those can eat the whole leaf in one day - that will definitely damage your harvest.  Natural way to protect your plants from being eaten up by leaf-grinders is to pick them up by hand. Remember that you are not a commercial grower, maximum 30-40 tobacco plants is all you need for the year. This number of plants is pretty small - you can manage it by hand, just walk around your garden every morning with your first cigarette in hand and pick up all the caterpillars you can see into a jar full of water - they are more visible in the morning before the mid-day heat, when they start hiding from sun. That is what we practice in our garden :) 

Harvesting tobacco leaves

There are different ways of harvesting your tobacco: 
1) pick leaves only
Start picking up leaves when they turn yellow - from the bottom of the plant. Picking process can last the whole season. At the end of season your plant may look like a bare stem without leaves - take them out of the soil and discard then. This method is used by commercial growers. Leaves require a special curing process when picked this way. 
2) harvest the whole plant
When bottom leaves are yellow (top leaves can still be green and growing) the whole plant can be harvested. At the end of season - before the first frost in your area - cut the whole plant with the sharp knife or saw at the ground level. This is preferable way for small garden, as even after harvesting the leaves on the plant are still alive and keep drawing nutrients from the stem during the curing.

Curing/Aging Tobacco naturally

Raw tobacco leaves must be cured before they can be used for smoking. Right after harvest they are NOT suitable for smoking yet. 

Curing leaves only process that commercial producers use is complicated and requires special equipment to keep constant temperature and humidity during the process.
 
If you cut the whole plants then you can use natural curing method. Just hang them upside down.
Unheated garage or barn which gets all the weather elements except the rain (moisture, wind, cold, heat) is the best place for natural curing.
During curing and aging process the leaves loose ammonia and other harsh chemicals, which makes smoking unpleasant. 
Tobacco will require long time to age - minimum 9 months, but the longer the better. Not aged tobacco is harsh and not of good for smoking.
Commercial tobacco is aged for 1 year or more before tobacco reaches consumers, and in commercial production aging process is kept under specific moisture and temperature regime. At home it is more difficult to control these parameters, but "time cures everything". This is a long process, so have patience.
There is a saying: the best tobacco is that was hung in the barn and forgotten for 2 years. It does get better with age just like wine !   

Accelerated curing process

For home made tobacco an accelerated curing method can be used, which makes excellent smoking tobacco from leaves picked in same growing season. The method is quite simple and does not require any special equipment. You can order the booklet here: Accelerated Tobacco Curing Method