My mother-in-law has large, beautiful lavender plants outside of her front door in southern Pennsylvania. All summer long, the plants produce profuse sweet-smelling blossoms that make me envious. Most lavenders are not cold hardy to northern New York. Luckily, there is a cold hardy perennial that is a wonderful substitute for lavender - Nepeta or catmint.
Nepeta is a member of the mint family that is extremely easy to grow since it has few pest problems and almost thrives on neglect. The plant's foliage is slightly aromatic and grey-green in color. The flowers can be white, pink, or lavender-blue and bloom on long spikes early in the summer. Cutting the plants back after the initial bloom often results in both a tidier plant and a new flush of flowers.
This deer-resistant plant is hardy to zone 4 and prefers full sun to part shade. Nepeta does best in a lean soil that is partially sandy. Too much fertilizer causes floppy foliage.
Nepeta is a classic underplanting for roses. The colors complement and the foliage hides the ugly "knees" of the rose bush. It is also a wonderful plant for edging, for spilling over walls and walkways and for softening spiky plants like iris and yucca. The pastel blues combine well with pinks and yellows, such as day lilies and yarrow (achillea).
Some suggested varieties to try include: "Felix" which is only 12" high and has vivid lavender-blue flowers; "Six Hills Giant" which is one of the tallest growing nepetas at 3 feet; "Sweet Dreams" is 2 feet high and has pink flowers with burgundy bracts; and "Walker's Low" which is about 2 feet by 2 feet and bears long spikes of lavender-blue flowers.
Most of the newer nepeta varieties are sterile so you won't be able to propagate them by seed. They do take well to dividing in the spring - which I like. I have some Walker's Low growing in front of a service berry tree and know of several other areas where it would look nice in my gardens!
Anne Lenox Barlow has had experience in the agricultural field as a horticulture educator with Cornell Cooperative Extension in Clinton County. She can be reached by e-mail at firstname.lastname@example.org.