Here we are at the sixth and final installment
of the companion planting series and today the topic focuses on the Nightshade
Family. The Nightshade family is scientifically known as the Solanaceae family
and it’s not a small family as about 2,700 plants are within it. Although the
family originated in South America members of this family now inhabit just about
every continent on Earth except for Antarctica. This diversification started after the
Cretaceous-Paleogene extinction event 66 million years ago and saw the mass
extinction of about 75% of all life on our planet. As such Nightshades
diversified over time becoming adapted to thriving in an assortment of land
types but also taking on a variety of forms ranging from epiphytes to trees. A
number of species developed a chemical defense in the form of high concentrations
of Alkaloid compounds; examples of this are the Nicotine in Tobacco or the
Capsaicin in Peppers. The name Solanaceae has some uncertain origins, it is
clear that it comes from the Latin word Solanum,
but it may come from the shape of many Nightshade plant’s flowers resembling a
sun. Take a close look at an Eggplant or Tomato flower and you can kind of see
how perhaps given the Latin word for the sun is Sol and the yellow flowers of a tomato are very star-like in shape.
Eggplants have a more noticeable and similar shape but often is white or purple
but they are still shaped similar to a simplistically drawn sun. Some sources
suggest Solanum came from the Latin verb ‘Solare’
which means “to soothe” and given the medicinal uses of some nightshades this
may have merit. Regardless of the origins of the name, it is clear what role
the most common nightshades in cultivation play in the garden when it comes to
companion planting. Without further delay here is a look at the most commonly
found nightshades in the garden trade and how they fit into companion planting.
Angel’s Trumpet (Brugmansia
species)
Angel’s
Trumpet when in full bloom is quite the sight to behold since the flowers have
scent and are large and dramatic in presentation. However unlike its annual
cousin Brugmansia prefers partial shade areas and pairs well with Marigolds and
Basil.
Bed of Nails (S.
quitoense) & Porcupine Tomato (S.
pyracanthum)
These strange
Nightshade relatives do double duty in the garden. The Bed of Nails has purple
spines while the Porcupine Tomato has bright orange-red spines and due to this
they both have a role as an annual part of defensive landscaping as most
animals and people will not mess with these plants. Only the Bed of Nails bears
edible fruit and both can be used to hold soil in place and are considered
short-lived perennials if brought in for the winter.
Devil’s Trumpet (Datura
metel)
Devil’s
Trumpet is sometimes called Jimsonweed, and these days it’s a very cultivated
garden annual that comes with double flowers but also has some needs to get the
best effect. Datura much like a Tomato needs a lot of organic matter in the soil,
regular fertilization and regular irrigation to do its best. Datura pairs well
with herbs such as Yarrow, Hyssop, Sage, and flowers such as Marigolds and
Verbena.
Eggplant (S. melongena)
Eggplant
comes in many shapes, sizes and colors ranging from the traditional Black
Beauty to the Turkish Orange Eggplant. According to a few references Eggplant
pairs well with Amaranth, and gains protection when planted near beans from
Potato Beetles. The one thing most people do not know about eggplant is that
they are very drought resistant once established and make excellent candidates
for xeric gardening.
Garden Huckleberry & Sunberry (S. melanocerasum) (S.
retroflexum)
While the
berries themselves are unsafe to eat until fully colored up, this plant adds a
critical bit of value to your garden in terms of companion planting. In trials
it was found that this plant was the preferred nesting site for Assassin bugs
which are insatiable hunters of other insects. If grown in large pots that are
moved about the garden as pest problems appear These plants help handle it by
being a home to even hungrier insects.
Ground Cherry (Physalis
pruinosa)
Ground
Cherries are grown a lot like a Tomato but have the physical structure that is
similar to Peppers in that they aren’t a vine, and they have this unique ‘V’
stem and branching structure. Ground cherries are easy to grow and you can tell
the fruit is ripe when you gently jiggle the plant and the fruits fall off.
Companion planting options for Ground Cherries include Basil, Thyme, Carrots,
Marigolds and Peppers.
Nightshade Greens (S.
macrocarpon) (S. scabrum)
The two
species of Nightshade greens are best known for their edible leaf greens. While
they both produce fruits the edibility of the fruit is not quite clear.
Nightshade greens are a bitter green akin in flavor to something like Broccoli
Rabe, and they are a bit rare in the United States. In growing trials last year
(S. scabrum) produced four feet tall
plants with large leaves that needed no support and seemed to help everything
around them grow. The other Nightshade green (S. macrocarpon) which is actually
a type of Eggplant, seemed to follow normal growing practices for an
domesticated eggplant, but had far better heat and drought tolerance.
Peppers (Capsicum annuum)
(C. frutescens) (C. chinense)
While there
is no consensus on exactly how many varieties of cultivated peppers there are
the range estimates upwards of 50,000 or more cultivated types. In general peppers grow well with a number of
leaf greens such as Dandelion, Chicory and Lettuce but Sweet peppers are known
to grow well with Basil and Okra.
Petunia (Petunia x
atkinsiana)
Petunias are
a fairly common annual flower available in a wide range of bloom colors and
come in double and triple bloom forms. A smaller flowered cousin the
Calibrachoa, a short-lived perennial fills in if you desire smaller more
delicate but also more numerous flowers. Petunias in general are known to
attract Hummingbirds and also protect Beans against Beetles.
Potato, White (Solanum
tuberosum)
Potatoes are
something that many gardeners try to grow but find varied degrees of success
because they require certain things to be productive. Deep soil that is heavily enhanced with
organic matter increases the chances of tubers, but also regular irrigation and
fertilizer helps too. The aforementioned practically means that in the home
garden growing potatoes in deep containers is the best way to go. In the view
of Companion Planting Potatoes do better when planted near Beans, Corn,
Cabbages, Marigolds and Eggplants. It is also suggested that planting Flax
between rows of Potatoes can help protect against Bean Beetles and Blister
beetles.
Tomato (Solanum lycopersicon)
Tomatoes are
a garden staple that many gardeners grow but can have trouble with in the North
Carolina climate. The main issues tomatoes face in NC are Blossom End Rot and
nutrient deficiencies. The former be cured with lime (or an antacid dissolved
in water) and the latter with Epsom Salt. Both are less likely to happen if
Tomatoes are paired with Marigolds, Carrots and/or Garlic. Some sources suggest
planting Borage which has edible flowers and edible young leaves.
Tomatillo (Physalis
philidelphica)
Tomatillos
are the larger form of Ground Cherry but also are not nearly as sweet in
flavor. Generally at the supermarket you will see the green fruit, but there
are also purple fruited types. Tomatillos pair with the same things as Ground cherries
but know that the plants get larger and may need more space.
Goji Berry (Lycium
barbarum)
Goji Berry is
a member of the Nightshade family that is rapidly gaining interest in the
United States and for good reason. Goji Berries are full of antioxidants,
vitamin A and C as well as fiver and iron. It’s noted that low growing plants
like Ajuga, Sweet Woodruff or Creeping Jenny will happily grow near this plant
and suppress weeds. In a container it is noted that annuals like Nasturtium and
Sweet Alyssum are good companions. What you should not plant near a Goji Berry,
is any other member of the Nightshade family or anything from the cabbage
family. Goji Berries need space to do their best and the plants around them
should not be competitive for nutrients.
Tobacco (Nicotiana
tabacum) (Nicotiana rustica)
True smoking
Tobacco can get very large, as individual plants can grow up to six feet tall.
If you decide to grow this know that it will need space, and that it will be
targeted by every hornworm within a few miles. If you’re not dead set on
growing a crop of leaves for smoking tobacco can make for a excellent trap crop
for things that otherwise would pillage your other Nightshades.
Tobacco, Flowering (Nicotiana
alata) (Nicotiana syvestris)
Flowering
Tobacco is the form of Tobacco that is not used for smoking, its main feature
is its beautiful flowers which bring in pollinators. Flowering Tobacco does
have a secondary use as a trap crop for Tobacco Horn Worms as they will often
go after it before they attack Tomatoes. In terms of companion planting, Flowering
Tobacco pairs well with Marigolds, Basil and Borage. You should never plant
Flowering Tobacco near other nightshades as it shares pests and diseases with
them and this can amplify your problems.
So, this
completes the 2026 discussion about companion planting. I hope all of you out
there found it interesting and if you have any questions please post them in
reply to this post.
