Q. How can I grow and care for English lavender?
Although lavender prefers a Mediterranean-type climate, it can be grown successfully in the Northeast if a few basic rules are followed.
First, it is important to choose the correct species and variety. For our climate, English lavenders (Lavandula angustifolia)are the best bet. 'Munstead' and 'Hidcote' are two popular choices. There are at least 100 cultivars of L. angustifolia,differing in flower color, scent, and growth characteristics. These varieties are worth exploring.
Nursery-bought plants of a given cultivar may vary greatly in appearance. This is because they are grown from seed and may not breed true to the original variety. If your plant doesn't develop as expected, try another source.
Lavandins, Lavandula x intermedia, are hybrids between L. angustifolia and L. latifolia. They are more tolerant of humidity and are hardy to Zone 7--suitable for the southern regions of the Northeast. 'Alba' (a white-flowered lavender), 'Grosso' and 'Provence' are all good choices to try.
All lavenders do best in very sunny locations (6-8 hours of sun per day) and need good drainage. If your soil is heavy, drainage can be improved by adding grit or coarse horticultural sand to the soil. They also prefer a neutral or slightly alkaline soil. If your soil is acidic, add lime to raise the pH (but not above 8.5). Lavenders can also be grown in pots. Use a free-flowing medium; water and fertilize regularly. As lavenders have an extensive root system, make sure to plant in a large container.
Prune your lavender regularly to reduce woody growth--woody plants produce fewer flowers. Prune in early spring when new growth has appeared. Lavender can also be trimmed in summer when flowering is finished. Bigger plants can have a third of their branches cut back every year or two.
Lavender flowers can be harvested and dried for continuing pleasure throughout the year. On a dry day, cut the stems just above the leaves. To ensure optimal color and scent, choose spikes on which only the lower flowers have opened. Tie the lavender stems in bunches with a rubber band, and hang upside down in a dark place with good ventilation. When no moisture remains in the stems at the center of the bundle--usually 2-4 weeks--your lavender is dry.
For further information on lavender, see Cornell's growing guide.