Butterfly bush (Buddleja davidii). Semievergreen or deciduous shrub with clusters of lightly scented, small lavender flowers on plants 6 feet tall or taller. Needs good drainage. Zones 2-24, H1.
Chinese wisteria (W. sinensis). Woody vine with lacy green foliage and clusters of fragrant blue-violet flowers. Zones 3-24.
Lavender. Many kinds have classic lavender scent. English lavender (Lavandula angustifolia), which grows to 3 1/2 feet tall and 3 feet wide, is among the most fragrant. Smaller 'Hidcote' and 'Munstead' grow to 2 feet tall. Zones 2-24.
Rosemary (Rosmarinus). Aromatic green leaves with grayish white undersides grow on woody stems. 'Prostratus' grows to 2 feet tall with a 4-foot spread; can trail straight down a wall. Perennial in zones 4-24, H1, H2.
- Limit turf. It needs more water than most other plants.
- Group plants with similar water needs. If plants that need to be watered at the same frequency and for the same length of time are all in one place, you can dedicate a separate line or valve to them, delivering exactly the amount of water the plants need and no more.
- Irrigate efficiently. Match the system ― whether drip irrigation, sprinklers, or soaker hoses ― to the situation, the soil, and the plants.
- Plant trees. Trees shade the ground beneath, lowering air temperatures and reducing moisture loss.
- Improve soil. Dig organic amendments into the soil to help its texture.
- Add mulch. Cover soil with a 3- to 5-inch layer of mulch to help conserve water by reducing evaporation.