Start by soaking the area, to leach out some of the acidity from the urine. Once it's dry, rake out or cut out the dead area. Prepare some soil - use existing soil and mix in ⅓ compost or use triple mix or a similar product that contains some soil and manure/compost. Fill in affected area and sprinkle seed on top - water in right away so seed has good soil contact. Keep area moist until seed germinates and starts growing. You can also use sod to fill in these patches. Dig out area, mix up new soil, lay down soil, cut sod to fit area, lay sod and keep watered until roots establish.

Here are some good choices for a North facing window - Aluminium Plant, Anthurium, Bromeliads, Chinese Evergreen, Cyclamen, Dieffenbachia, Dracaena, English Ivy, False Aralias, Goldfish Plant, Monstera, Peace Lily, Peperomia, Philodendron, Pothos, Rex Begonia, Schefflera, Snake Plant, Spider Plant.

Hawthorn, Amur Cherry, Amur Maple, Showy Mountain Ash, Ornamental Crabapples, Japanese Tree Lilac, Pin Cherry, Amur Maackia, Fern-leaf Caragana, Weeping Caragana, Apricot, Autumn Brilliance Serviceberry, Princess Kay Plum, Weeping Norway Spruce, Bakeri Spruce, Montgomery Spruce, Moonglow Juniper, Witchita Blue Juniper, Medora Juniper, Russian Mountain Ash, Muckle Plum, Plum, Cherry, Young's Weeping Birch, Bristlecone Pine.

Swedish Columnar Aspen, Tower Poplar, Siberian Columnar Crabapple, Columnar Mountain Ash, Columnar Blue Spruce, Columnar Norway Spruce, Columnar Scotch Pine, Sutherland Caragana.

Some to the best plants for a south window are Bougainvillea, Cacti, Citrus, Hibiscus, Jasmine, Kalanchoe, Miniature Roses, Oleander, Passiflora, Succulents,