Question
I live in Washington DC.  I love thyme, but have the hardest time growing it in pots.  The birds destroy my plants if I leave them outside, so I have to keep them inside, where it is usally air conditioned to about 70-75 degrees.  I grow them in regular potting soil in 6" clay pots and water regularly, letting the soil dry before rewatering.  They sit in a window where they get full morning/ to early afternoon sun.  The plants don't grow and the leaves are shriveled and yellow.

Answer
Dear Ken:

Thank you for your question.  Let's see what we can do to help you out.  The symptoms that you describe ( stunted growth, yellowing leaves ) are classic symptoms of over-watering. You've told me that you let the soil dry before watering, but how do you check it?  In a six inch pot you should push your index finger down to the third knuckle and still feel dry soil.  Is the pot completely filled with soil?  I always put about one inch of small stones in the bottom of a pot to provide good drainage.  Placing a round saucer underneath the pot helps hold excess water.  You can get clay ones at your local garden supply store made specifically for this.
Thyme likes full sun and somewhat warmer temperatures than you describe.  I have alot of thyme growing in our garden in Pennsylvania and have never had birds bother it.  Are you sure that birds are the problem?  You could have an insect issue.
Here is my suggestion:
Repot your plants.  Put saucers or trays under the pots and place the stones in the bottom of the pots.  Cut away the yellow / sick parts of the plants.  Don't be shy, cut back hard.  Water them well and place them in the sunniest window that you have.  When you repot, check the roots of your plants.  Are they moldy?  If so, they are definately getting too much water.  Sit back and relax for ten days - two weeks with out rewatering.  Let me know what happens.  Feel free to respond to the questions that I have asked so that we can try to pin point your problem.  If you think that birds are really the issue when keeping the plants outside, you could try building a cage to cover them with as well.
Keep me posted . . .    David F. Balshukat