Wellness is as close to you as the kitchen pantry; the easiest way to include herbs in your life is to start cooking or snacking. You don't have to be a culinary whiz. You can use herbs as add ins to things you've purchased.
While Vitamin C isn't an herb, it is wellness that can be easily accessed in many of our foods as well as some wild herbs. Vitamin C can be found in citrus, but also in berries. Some wilder options would included pine needles, which have been traditionally used to treat vitamin C deficiency in the form of scurvy.
Vitamin C is an astringent, which means it draws tissues together. That's why you see astringent herbs, like witch hazel, included in facial treatments as a "toner"; toning is tightening, sealing, and astringent in action.
Another way to get this astringent action is to employ things with tannins. If you've ever had a glass of wine, you'll know that puckery, drawing feeling. That's all due to tannins.
A side note: there is balance in all things. As much as you do want to close the pores, you also don't want to dry yourself out. A door that's weatherbeaten and shrunken will not keep out the cold, and neither will dried out skin. Having hydrated skin will also help. In the winter it's easier to hydrate by using oilier substances instead of watery ones. You can feel the difference between a thicker, oilier covering and a thinner, cooler, watery one.
Cold and flus get in our system through the mucus membranes and skin. The best offense is a good defense - if you can close and seal up the pores and membranes, then those pesky little bugs will have a harder time getting into your body. This is good preventative nutrition.
If a virus does manage to get in, you'll need to change your tactics. Microbes are like an invading army that has breached your walls: once they're in, outer wall reconstruction isn't going to do you much good until the battle is over. You want to rally the troops to protect your more vulnerable inner organs, like your lungs. At this point, you would stop sealing and start working on an exit strategy by opening your pores.
Some good food and herbs with Vitamin C are:
*traditional citrus fruits: oranges, lemons, and limes
*berries: blueberries, strawberries, and raspberries (but these can be very cooling,
so might be a little chilly for colder seasons)
*other berries: elder and aronia berries
*more "exotic" herbs: pine needles (they make a great tea or potpourri!)
Some good sources of tannins:
*raspberry leaf tea
*black and green tea
Some good oils to keep moistened in the winter:
*safflower oil (very good for Raynaud's)