Claire says that she planted tulip bulbs in the fall, but tulip bulbs are planted in the winter when it is cold outside.
This is true for areas where the ground does not freeze. However, this is set in the Washington DC area where the ground does freeze and tulips must be planted in the fall.
When Clare and Gillian are talking about Gillian refusing the job offer from Google Clare notes how there is no malaria in Palo Alto. Google is in Mountain View.