Many students and teachers miss the school garden during the winter months. For a triple bonus of good looks, good flavors and good scents, consider growing herbs inside the classroom to chase away the winter doldrums and get your winter garden fix. Even just a few pots of herbs indoors can supply you and your students with wonderful scents and flavors while teaching them about science and plants.
There are some caveats to growing herbs indoors in the winter. They are sun-lovers, and will need a good, south-facing window with at least four hours of direct sun each day to do well. If you do not have a window with these specifications, try growing your herbs under lights.
Some herbs are better suited for indoor winter cultivation than others. Below are a few tried and true performers with consistent and compact growth:
· ‘Grolau’ chives (Allium schoenoprasum): Strong flavor and thick, dark green leaves that were developed for forcing. They grow eight to 12 inches tall and seeds germinate in 10 to 14 days at 60° to 68° F.
· ‘Fernleaf’ dill (Anethum graveolens): Dwarf form of dill that only grows 18 inches tall and is the ideal type of dill weed for indoor conditions because the standard varieties grow too tall and bolt too soon. They are easy to grow from seeds and germinate in 7 to 14 days at 60° to 68° F.
· ‘English’ mint (Mentha spicata): This is perhaps the best-behaved spearmint variety because it is not as invasive as others and the leaves are broader and a deeper green.
· ‘Spicy Globe’ basil (Ocimum basilicum minimum): Dense, compact form of basil that grows 8 to 10 inches tall and has good flavor. It should be grown from seed and germinates in 6 to 12 days at 68° to 77° F.
· Greek oregano (Origanum vulgare hirtum): The true oregano for Mediterranean cooking has excellent flavor and white flowers. Watch out for the imposter, called wild marjoram, with pink flowers and no flavor. Greek oregano grows well in pots, reaching 8 to 12 inches. It is easily grown from seed in seven to 21 days at room temperature.
· Broadleaf thyme (Plectranthus amboinicus or Coleus amboinicus): Also known as Spanish thyme and Cuban oregano, this plant has broad, fleshy leaves unlike those of ordinary thyme. It never goes dormant and reaches 10 to 12 inches tall.
· Vietnamese coriander (Polygonum odoratum): Not true coriander, but it makes a good substitute. It regrows after cutting, unlike true coriander, which must be reseeded after harvest. It grows to be four to eight inches tall.
· ‘Blue Boy’ rosemary (Rosmarinus officinalis): This more compact and diminutive variety of rosemary compared to regular rosemary, reaches only 24 inches tall. It flowers freely and has excellent flavor.
· Dwarf garden sage (Salvia officinalis ‘Compacta’): With smaller leaves and a more compact habit than regular sage, this variety grows only 10 inches high with the same sage flavor.
· Creeping savory (Satureja repandra or S. spicigera): Flavor identical to that of winter savory, but easier and faster to grow indoors, this savory reaches only two to four inches in height, but fills the pot with a dense mat of foliage.
Other herbs that are not good candidates for winter indoor growing include full size cilantro (coriander), dill and garden cress; these herbs do not regrow when cut for harvest. You can grow parsley from seed indoors, but do not expect it to get as big as when you grow it outdoors.
Growing herbs indoors can reap the benefits of hands-on, interdisciplinary horticulture experiments and projects as well. Try growing herb plants in pots within a window box with soil filled up to the top of the pots. Compare this growing method with normal growing conditions (just pots) and have your students come up with hypotheses about the results.
Besides all of the previously mentioned benefits, growing herbs in the winter can also help keep students’ and school staff spirits up for spring. Just crushing a basil leaf under my nose on the coldest, dreariest winter day can bring on a sense of well-being and hope.
This article was published by Michigan State University Extension. Reprinted with permission