Companion Planting Series: Part Six - The Nightshades

           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.

Companion Planting Series: Part 5 - The Mint Family

Orange Mint, a peppermint cultivar

Good Morning Neighbors,

 

          As promised today we’re going to talk about the Mint Family and its use in Companion Planting. The Mint family is currently known by its scientific name Lamiaceae but in older books and publications you will see the name Labiatae. I’m sure some of you looked that that old name twice but it’s not quite as dirty as you might think. The name refers to the fused upper/lower portions of the flowers which are called lips, and in Latin the word for that is ‘labia’ thus the name. Mint flowers always look a certain way and have a certain shape which most gardeners probably can spot easily even when the flowers are tiny as they have five petals and five united sepals. Typically mints have a square shaped stem but this is not always true and square stems can be found in other plants that are clearly not in the Mint Family. The biodiversity in the family is quite impressive as there are about 236 genera, and up to 7,200 recorded species in the family. One of the most famous members of this family is a tree that is critical to woodworking especially in the maritime trade. Teak (Tectona grandis) has been critical for ship building for centuries because of its ability to resist the weathering of being exposed to whatever Mother Nature throws at a ship. In relation to what all of you out there are liable to use in your gardens the Mint Family has you covered from numerous angles. It’s hard to say which member of the Mint Family is most planted though because in the garden the options are so diverse; for example in your spice rack alone there are at least five perhaps six things that represent the family; Basil, Rosemary, Sage, Thyme, Oregano and/or Marjoram. If you have a more comprehensive spice rack, you might have, Thai Mint, Lavender, Peppermint, Greek Oregano, Zataar, and the list goes on. Outside of culinary stuff, the Mint Family has several members that have herbal uses as teas and have a history of being used in foods such as candies and chewing gum. On the medicinal side of things many of the mints are known for having antimicrobial properties, and are used in various cough and cold formulas. In the news within the last few years there was a big issue over the use of Menthol in Cigarettes because of how it makes becoming addicted to cigarettes easier by numbing the throat. I’m not even going to get into how a specific variety of Mint makes your Mojito taste the way it does. The point is the Mint Family is large and in charge and today we’re going to have a good look at the ones that are best for your garden.

 

 

African Potato Mint (Plectranthus rotundifolius)

 

          I had to include this one because the plant is pretty weird. Most folks have not heard of African Potato Mint, but a look at the scientific name and some will realize this thing is related to Swedish Ivy (P. verticillatus) and Cuban Oregano (P. amboincus) this unusual plant was once grouped with the Coleus, which are also in the Mint Family. Potato Mint is grown for its edible tubers which are said to have some sugars that are not digestible and maybe give some folks gas. The indigestible sugars/starches might also mean that this plant is really useful to those with Diabetes. In addition to the tubers some sources indicate the foliage may also be edible, the one thing that is sure is that this plant does not form tubers until the days shorten and the foliage has died back. The tubers do not store well so perhaps it has some use as a house plant, its companion planting value is unclear.

Anise-Hyssop (Agastache foeniculum)

 

          Anise-hyssop is not the same plant as Hyssop (Hyssopus officinalis) and is valued in the garden for a different reason. Medicinally Agastache is useful for its Licorice-scent and its ability to help with coughs and colds. Anise Hyssop is best known for the wide selection of foliage color and its flowers which attract pollinators. As such they pair best with other flowers to create a stable source of food for your pollinators.

 

Basil (Ocimum species)

          Basil is a critical culinary herb that is best used when fresh but loses something in the aroma and flavor department once dried. There are a number of varieties of basil available on the market such as Lemon Basil (Ocimum x africanum), Lettuce Leaf Basil, Cinnamon Basil, Thai Basil (O. b. variety thrysiflora), Blue African Basil (O.  kilimanscharicum x basilicum ‘dark opal’) and Cardinal. In short for every need there is a basil to suit your fancy, and as a member of  the mint family it’s a good partner for the Nightshades and Asparagus but many references indicate it does not do well near Rue (Ruta graveolens).

 

 

Bee Balm (Monarda species)

 

          There are several species of Bee Balm on the market and the one photographed is actually Wild Bergamot (Monarda fistulosum). What is sold in most garden centers and nurseries is Scarlet Bee Balm (M. didyma) and there is a fair range of bloom colors and types within that. The aforementioned type of Bee Balm from seed typically blooms in its second year, and is considered a native herbaceous perennial. Bee Balm is valued for its intensely colorful flowers which attract pollinators and Humming Birds however its leaves can be made into a tea which was Called Oswego Tea by Colonists when actual tea ran short. As such the chief companion planting use of Bee Balm is to bring in Pollinators which then hit up your other plants.

 

 

Bugleweed (Ajuga reptans)

 

          Some of you probably did not expect this perennial plant to be in this listing, but yes it is a tried and true member of the Mint Family. It is a non-native that in some places has been determined to be invasive and that listing is perfectly understandable. However when in control in your garden, it has a secret superpower for companion planting. Unlike the other plants I’ve spoken of Bugleweed has the ability to make topsoil. The dense mats of foliage and the pretty flowers are all just a cover for what happens under the plant’s ground cover canopy. You see, it creates a little microclimate and haven for decomposers wherever it’s the dominant low-growing plant. It sheds its leaves and dead flowers into that micro-canopy; soil organisms eat that and turn it into topsoil. In addition to this the foliage catches bits of detritus that would otherwise float by in a rain and it gets trapped in there and breaks down. After a few years there might be a quarter to a half inch of fertile topsoil and the best part is that the Bugleweed has grown up so it’s always on top holding that soil in place. If you punch a few holes in that and plant tall things the Bugleweed acts like a living mulch and soil producer. The only catch is you have to remember to water it, Bugleweed is very dramatic about wilting and does not tolerate drought. The big downside to this plant is that it is not edible nor is it safely used as a medicine, but it does bring in pollinators.

 

 

Catnip (Nepeta cataria)

 

          You all knew this was going to be in here, Catnip is a very obvious member of the Mint Family and one of those herbs that you really only grow for one reason. In the southeast it is a short-lived maybe-deciduous perennial that often persists for 2-3 years and may reseed itself from seed. The primary reason to grow this plant is for your cats; however it does also make a decent tea. Drinking catnip as a tea may impart a bit of insect repellant as it contains nepetalactone which can come out in your sweat. As a companion plant Catnip generally can be planted anywhere and if not demolished by a neighborhood cat its flowers are very attractive to pollinators.

 

 

Cuban Oregano (Plectranthus aboinicus)

          Cuban Oregano is a semi-succulent plant with leaves covered in essential oils and alight fuzz on all surfaces of the plant. Most folks liken its aroma and flavor to it being a love child between basil and Oregano, though the variety called ‘Cerveza and Lime’ adds citrus to the mix at the cost of comparatively smaller leaves. In both cases Cuban Oregano is generally grown like one might grow a Coleus, partial sun regular watering and the expectation that repotting might be needed at least once per year. In terms of pairings Cuban oregano grows well with the Nightshades and its strong sent can stop animals from digging in areas. To that end there is a relative of Cuban oregano called the ‘Piss Off Plant’ (P. caninus) which is inedible but also a straight animal repellant.

 

 

 

Henbit (Lamium amplexcaule)

 

          Henbit is a cousin of Spotted Dead Nettle (Lamium maculatum), that found itself in the weed listings for no real good reason. It isn’t native but it is the annual plant that creates a purple haze in lawn areas in late winter or early spring in the southeast. Its chief companion plant pairing seems to be just about anything but its not aggressive and falls apart when the weather stays over 70 degrees. It is a good food for poultry and its presence can often tell you that there is an area with decent soil and some regular moisture.

 

Horehound (Marribum vulgare)

 

          Horehound is a herbaceous perennial that is the source of essential oil for those old school cough drops you see at the pharmacy on the candy rack. The word ‘Hore’ in its name refers to the ‘hoary’ foliage meaning it’s gray and furry. The plants themselves are bitter tasting which discourages grazing animals from messing with them which means they can be used to prevent deer damage but their main value is the flowers which bring in pollinators and some sources suggest that Horehound directly stimulates fruiting in the nightshade family.

 

 

Hyssop (Hyssopus officinalis)

 

          Hyssop is not a herb you see in gardens much these days because its use has somewhat fallen out of favor. This may be because of a decline in knowledge of practical applications of herbs or perhaps because Anise-Hyssop (Agastache foeniculum) has stolen its thunder. Hyssop is known to be drought resistant and tolerant of sandy soils while preferring full sun exposure. Hyssop’s medicinal value is that its essential oils have antiseptic properties while compounds in the foliage stimulate the nervous system. Compresses made of Hyssop foliage can also help clear up the discoloration of bruises. As a companion plant it’s flower will bring in the pollinators particularly Honey Bees.

 

Lamb’s Ear (Stachys byzantina)

 

          Lamb’s ear is a quintessential cottage garden perennial that has an interesting history as its fuzzy leaves were once used as bandages during the American Revolutionary War and presumably again during the American Civil War. While it is not a native plant, it is hardly one anyone could consider to be an invasive plant due to its low rate of spread. Lamb’s Ear is considered evergreen but usually somewhere in winter in our area it may die back, need the dead leaves cleaned out and then it recuperates by early spring. In terms of companion planting, Lamb’s Ear has a neat trick most people don’t know about. Unlike a lot of other plants Lamb’s Ear has a high rate of evapotranspiration meaning that it can pull water out of the soil and put it back in the atmosphere which makes it useful for handling floods and rainwater retention. Extracts of this plant have antimicrobial effects against Staph bacteria. Lamb’s ear grows well with Lavender and Salvia.

 

 

 

Lavender (Lavendula x intermedia ‘Phenomenal’)

 

          Yes, you read that right. Lavender is in the Mint Family, and when you really think about it is that any surprise? Lavender is a genus of about 47 species of plants that have a fair amount of variety and to that end I can say, that only one particular cultivated variety has passed the growing test for our climate and that’s a variety called ‘Phenomenal’ which lived for about seven years when most others can’t even handle three years. Lavender is noted to repel ticks. Before you go nuts with planting lavender because you know you have ticks know that it’s application of the plant’s essential oils. The oil itself can kill ticks but it has to touch them first and the studies behind this were only on the Yellow legged tick found in Africa and the Middle East. There is no telling how well it works on our three most common species of Tick in North Carolina. Lavender is said to repel rodents because of its strong aroma as an essential oil messing with their ability to navigate and forage for food. A third use, repelling Clothing moths and their destructive larvae is proven, but the catch is again that it relies on aromatic essential oils and is best used before a problem is detected. Beyond all the aforementioned, the blooms attract a lot of pollinators, and its foliage and flowers are food-safe

 

 

 

Lemon Balm (Melissa officinalis)

 

          Although what is pictured is actually Orange Balm (M. o. ‘Mandarina’), which defies the normal rules on growing Lemon Balm the uses of both are the same. Lemon Balm is an fairly common herb that is known for its lemony flavor and fragrance. While it isn’t quite as lemony as Lemon Thyme or Lemon Verbena it makes up for that with being a hardy herbaceous perennial that returns year after year without fail. Lemon Balm seems to pair well with anything just as long as it gets enough sun and irrigation to produce its flowers which are noted to be preferred by Honey Bees.

 

 

Mountain Mint (Pycnanthemum muticum)

 

          The common problem with the plants we think of as Mints is that they readily escape cultivation and can go invasive. Mountain Mint on the other hand is well-behaved, generally does not escape and can tolerate hotter drier areas and its flowers bring in a plethora of pollinators including a lot of non-aggressive solitary wasps of all colors and shapes. In terms of flavor and scent this plant is similar to Spearmint with a bit of something else it has all the same uses as Peppermint or Spearmint but has a vertical growing habit and woody stems. There are a few species of Mountain Mint and generally they are native to North America. I recommend looking for Blunt Mountain Mint because its leaves are far easier to harvest and use, and its flowering heads are something to behold. As for Companion Planting, this particular mint brings in the pollinators, and some of those pollinators are great at reducing caterpillar populations such as Tomato/Tobacco Hornworms.

 

         

 

Oregano (Origanum vulgare)

 

          Oregano is one of the rare exceptions when it comes to herbs; it is more aromatic and pungent once dried. I jokingly call Oregano ‘Sand Mint’ because of how aggressively it has spread in the test garden but it’s main effect is without comparison, it holds the soil against erosion, it’s flowers in the summer help sustain the pollinator population and it’s dense growth builds the soil in a similar but larger scale to what Bugleweed does. As a Companion plant I’ve found that it’s excellent under fruiting trees such as figs, it suppresses weeds and weed-trees and the figs inevitably grow too tall for the oregano to compete. When the oregano wilts, it means the Figs also need a full irrigation run.

 

Peppermints (Mentha x piperita)

 

          Although it’s rarely mentioned, Peppermint is actually a stable hybrid; a cross between Watermint and Spearmint. Peppermint has been around and its essential oils are in so many things that a lot of people have no idea that it is a hybrid. It was first identified in Hertfordshire, England and later included in the second edition publishing of Synopsis Methodica Stirpium Britannicarum in 1696. Peppermint was later added to the London Pharmacopoeia in 1721. Linnaeus gave it the name (Mentha piperita) in1753. With that said, Peppermint really gets around because there are dozens of cultivars in circulation in the horticulture world such as Chocolate Mint (M.x.p. f. citrata ‘Chocolate’), Orange Mint (M.x.p f. citrata) and Strawberry Mint (M.x.p. ‘Strawberry’) and many others. Now this is where I will disagree with may sources on companion planting because they suggest it’s a good Companion for Onions, Beets, Cabbage, Pumpkins, Zucchini and Carrots. The problem is that Peppermint can be very aggressive and so it should be grown in large containers that are raised up off the ground so it cannot escape. Its chief contribution is that when it blooms it brings in the pollinators which can help your garden in general.

 

 

 

Rosemary (Salvia rosemarinus)

 

          Rosemary is ultimately in the Mint Family despite being in the same genus as Sage.  Rosemary generally does best in full sun and benefits from early applications of slow-release fertilizer or compost and a 50% cut back every three years or so. Rosemary being one of the primary aromatic herbs does well when paired with Carrots, Cabbage and Nightshades but care must be taken to space these plants out so the Rosemary does not end up being buried in other plant’s foliage.

 

 

Sage (Salvia officinalis)

 

          The plant in the included image is Golden Sage (S. o. ‘Golden’) which is a cultivar of Common Garden sage.  Sage in the southeast is a snort-lived perennial most of the time due to our heat and humidity. It is not uncommon to need to replace a Sage plant every three to five years, though some of the ornamental sages ignore this expectation completely. Sage itself is a major culinary herb that has a lot of uses in the kitchen and also has a few herbal and medicinal uses otherwise. Sage blooms in the cold months and provides nectar and pollen to whatever pollinators are active at the time making it essential for a year-round approach to supporting pollinators.  It is stated in a few books that Sage is protective to the cabbage family and may improve their flavor. Sage may also improve carrots but should not be planted with Cucumbers.

 

 

Spearmints (Mentha spicata)

 

          Spearmint has a number of varieties on the market with the most well-known being ‘Kentucky Colonel’ which is a bit aggressive unless you’ve got hot dry soil. Spearmint has all the same uses as Peppermint and should be confined to a large pot for your garden’s sake, its flowers also bring in the pollinators.

 

Thai Mint (Mentha arvensis)

 

          Thai Mint is a different kind of mint because its flavor is noticeably different then Peppermint or Spearmint. It follows the same rules as the other two, except it is a bit pickier about needing fertilizer and irrigation. It should be confined to a large container and it does without fail emerge in late winter before Spearmint and Peppermint is actively growing.

 

Thyme (Thymus vulgaris)

 

          The Thyme pictured is Lemon Thyme (Thymus citriodorus) which much like Common Thyme is an evergreen low-growing perennial with aromatic leaves. I personally only grow Lemon Thyme because it’s essential for proper lemon pepper gravy and for cooking any form of sea food. Thyme is considered a short lived perennial in the southeastern climate because our summers and lack of a longer winter are not idea for its health. Thyme is known for its herbal-medicinal capabilities as an antimicrobial but in the garden its ability to repel Cabbage worms is noted also.

 

          So that wraps up a pretty detailed look at the mint family and their uses in the garden from the purview of companion planting. As with the Aster Family I know that I definitely did not cover all the popular members but I got most of them today. Hopefully you can put this information to good use in your gardens. Thank you for reading and stay tuned for next week’s post.