You have a full frame camera, you wont have crop effect that means you get actual frame according to the focal length(35mm or 24mm).
As your interest in landscape, its better to go for 24mm of focal length, but again as you also said you need shallow depth of field and you like portraits, 35 mm is what i recommend for that purpose that has 1.8 aperture. 35 mm falls under 24-85mm but you then compromise its lowlight capability and Dof.
so i would recommend you to get 35mm for its versatile capability for detail shots on street and portraits and 24-85 for landscape and for situations you cant move close for shots.
For your interest you need both the lenses. If budget is a constraint i would say to go for 35mm lens first as it gives so much for that price and later 24-85mm which is almost $300 expensive to 35mm.(also see Sigma 12-24mm F/4.5-5.6 EX DG HSM II which is much wider but expensive too).