I’ve always admired the gardeners who harvest all manner of fragrant herbs
within steps of their kitchen door. Unfortunately, given the location of my
herb patch, I can’t just pop out and snip a bit of this or that. Then one day
it occurred to me that my herb garden needn’t be in the ground. I could have
my favorites within arm's, length without having to go outside or even get out
of my jammies. All I had to do was design a window box around herbs instead
of my usual annual flowers. The result turned out to be beautiful as well as
functional. Best of all, planning and planting the herb box was a snap.

Location, location, location.

When considering your own mini herb garden, decide where your box will be
located. The amount of sun you’ll get will dictate which herbs to select.
Southern and western exposures are generally sunny and hot. Good choices for
these situations are coriander, thyme, French lavender, bay laurel, basil,
lemon verbena, dill, parsley, chives, rose scented geraniums, sage, rosemary
and heliotrope. A combination of upright and trailing herbs is the most
pleasing to the eye, so consider adding creeping thymes, oregano, nasturtiums
or prostrate rosemary to your mix.

 Northern and eastern exposures will likely be shady and cooler. Many
shade-lovers will shine in your window box environment, including parsley,
nasturtiums, spearmint, lemon balm, chives, comfrey, borage, bergamot,
peppermint, sweet woodruff and Cuban oregano.  Tuck English ivy in the
corners of the box to add visual interest.

Window box basics.

Fill your box halfway with a potting mix that combines equal parts of potting
soil, peat moss and vermiculite (or perlite.) You may also want to add a bit
of water-absorbing polymer to help your box retain moisture.

Move your herbs around until you find a pleasing design. Keep growth habits
and sizes at maturity in mind. For example don’t place dill in front of
diminutive thyme. Don’t be afraid to cram all your plants in together. I
jammed 15 herbs including four types of basil into an 8" by 24" box last
April. Six months later the basil has petered out but everything else looks
great.

Once you’ve settled on the placement add potting soil to about 1 inch below
the rim of the box. Tamp the soil down firmly and water generously. At this
time you may want to pinch back to encourage bushy growth.

Day-to-day care.

Don’t forget that window boxes in sunny locations will need to be watered at
least once a day.  Water can contribute to loss of nutrients so be sure to
maintain a regular feeding program. Apply an organic fertilizer high in
nitrogen or liquid fish emulsion every two weeks. As herbs mature, pinch off
developing flowers to prevent the plants from setting seed. As part of your
weekly grooming program remove any yellow foliage or damaged branches. Good
maintenance habits will prevent your window box from looking scraggly by the
end of summer.

    Luckily, herb window boxes aren’t usually plagued by pest problems. It
still pays to keep an eye out for aphids, whiteflies and spider mites. A
strong spritz of water on a hot day can help deter spider mites. Consult your
Growise expert for tips on selecting an insecticidal soap should pests get
out of hand.

Changing with the seasons.

    When summer turns to fall you may want to bring some of your favorite
herbs indoors to live in a sunny window.  Otherwise, most annual herbs like
basil will turn black with the first frost. In most northern climates even
the perennials will not survive the winter in an exposed window box. You’ll
just have to start again with new plants next spring.

On the other hand, hardy rosemary, lavender, germander, parsley, sage and
thyme may well live through the cold weather, especially if situated in a
sheltered location. Like me, these lucky gardeners will be able to open the
window and harvest a fresh sprig of rosemary or thyme to season a holiday
meal. It’s a satisfying experience knowing you still have the pleasures of
the summer herb garden within your reach.