Companion Plants for Your Cannabis Grow

A companion plant is any species you deliberately sow next to your main crop because it earns its space. Some pull pests away from your cannabis, some bring in pollinators and predatory insects, some cover bare soil so it stops drying out by lunchtime, and some simply make the whole corner read as a herb bed. Companion planting is old, far older than any of us: plant pairings show up in the archaeological record across Europe, Asia and the Americas. The modern version is the same idea with better labels. More plant diversity in one bed usually means healthier soil and less reaching for the bottle of insecticide.

Four Buddy Mix Packs, Four Jobs on the Plot

The Buddy Mix Packs are named after the work: SCARE, DEFENDER, STEALTH and NUTRIENT. If you do not fancy researching a dozen species before you sow anything, that is the shortcut. Decide whether your problem is bugs, prying eyes or tired soil, sow that mix along the edge of your bed or in a pot beside your main plants, then fill in with single-species Buddy Packs once you know which corner of your plot stays hot and which stays damp. Growers who already know their plot usually skip the mixes and buy loose: a Marigold Buddy Pack for the border, a Cerastium Buddy Pack for the soil surface, done.

SCARE and DEFENDER: Bugs That Turn Around Before They Land

Marigold (Calendula officinalis) has been the border plant in prized display gardens for centuries for one reason: it puts insects off. It deters beetles and leaf hoppers, Mexican bean beetle and bad nematodes, and French marigold roots produce a chemical so strongly insecticidal that the effect lingers in the soil for years after the plant has died back. The flowers are cheerful orange with a soft, slightly resinous scent when you brush past them, which is more than you can say for most pest control. Once they finish, the spent foliage goes straight on the compost heap.

Catmint (Nepeta mussinii) does two things at once. It pulls pollinators in while pushing mosquitos and cockroaches away, it is hardy enough to sow straight outside, and the leaves brew into a decent tea. Watch out for the obvious side effect: every cat in the street will find it, and a determined tomcat flattening your border is not the look you were going for. Sunflower (Helianthus annuus) works the other way round, as a decoy. Aphids and similar pests go for the sunflower instead of your plants, and the thick stalks and tough leaves shrug off a lot of damage. Better sunflowers than cannabis.

Rue (Ruta graveolens) is the other classic in this group, though it comes with a warning we would rather you read now than later. Skin contact with rue leaves can cause irritation, and sunlight makes that reaction worse, so pull on gloves whenever you weed or prune around it. Its culinary use has largely been dropped, and it should be kept away from pregnant women and anyone with liver issues. Alongside those, the Buddy Pack line covers Yarrow, Chamomile, Dill, Coriander, Chervil and Borage, all flowering species that keep insect traffic moving through the bed instead of parking on your cannabis.

STEALTH: A Border That Reads as Somebody's Herb Patch

Concealment is the reason plenty of people land on this page. The trick is height and mixed scent. Lovage (Levisticum officinale) is the tall one, a leafy perennial that stretches towards 2m and hides a lot behind it, while a mature Sunflower stands head and shoulders above everything else in the bed and nods its head east once it is done growing. Ring the front with Lavender, Sweet Basil, Peppermint and Lemon Balm and you have a bed where the strongest smell at nose height is herbs. Anyone glancing over the fence sees somebody who is very into cooking.

Be honest with yourself about the limits, though. A herb border is not a wall. A single plant that towers over a metre of lavender still draws the eye, and scent cover does nothing about the shape of a fan leaf at eye level. Plan the layout so your tallest companions sit between the plants and the sightline, not behind them, and keep your own plants short enough to sit inside the crowd rather than above it.

For balconies with no ground to plant in, the Geotextile Fabric Wall Planter (10L) by Gronest gives you a vertical option. It is made from recycled PET bottles, and the installation kit bag comes with the screws and dowels to hang several side by side and above one another for a green wall of strawberries, flowers or fragrant herbs. The fabric changes how the roots behave too: instead of circling the way they do in a hard plastic pot, they spread more naturally, and any water your soil cannot hold just runs through instead of sitting there drowning things.

NUTRIENT: The Plants That Pay the Soil Back

Bare soil around a pot or a bed is wasted soil. It bakes, crusts over, and loses water every sunny afternoon. Cerastium (Cerastium biebersteinii) is the answer we reach for most: a fast-spreading perennial that forms a thick mat of silvery grey leaves with a shower of white flowers in late spring, and that mat shades the ground and cuts evaporation. It also throws out a lot of foliage in a short life, so it doubles as compost material. The catch is right there in its habit. Cerastium can turn invasive, so do not be shy about hacking into it when it gets greedy for room. It wants full sun and gritty, well-drained ground.

The legume side of the NUTRIENT idea is covered by the White Clover, Red Clover and Alfalfa Buddy Packs, the traditional green-manure and living-ground-cover choices, sown thick and either left in place or turned in. White Mustard (Sinapis alba) is the quick one: sow in March and it is ready by summer, and it asks for little beyond moist soil and normal light and warmth. The seeds go into cooking, sauces and pickling, and the young leaves into salads, so nothing is wasted if you decide not to dig it in. Dandelion (Taraxacum officinale) seeds sit in the same part of the shelf if you want a deep-rooted perennial in the mix.

Slotting Companions Into a Grow That's Already Running

Timing matters more than spacing. Some of these want a head start indoors, some go straight out. Sage (Salvia officinalis) germinates in an indoor propagator in late autumn or early spring and moves outside after the last frost, once the seedlings have their first set of true leaves. Lovage is the same story: start it indoors in spring, harden it off once it has two sets of leaves and the frosts are gone, then plant into deep, fertile, well-draining soil in full sun, slightly acidic at around 6.5 pH with plenty of organic matter. Catmint is happy sown directly outside in late spring. White Mustard goes in in March.

Cumin (Cuminum cyminum) is the one that most often disappoints, so know what you are signing up for. It needs a long, hot season, started about four weeks before the last frost and only moved outside once temperatures sit above 15°C. It flowers in mid-summer and takes roughly 120 days to be harvest-ready, which a cool northern summer will not always give you. If you want a reliable culinary crop instead, German Winter Thyme (Thymus vulgaris) is a Mediterranean perennial that stays in the garden for years in loamy, well-draining soil and full sun, and Oregano (Origanum vulgare) copes with dry spells once it is settled.

On placement, keep it simple. Put the tall companions where they will not throw shade across your main plants for half the day, run low growers and ground cover right up to the base of the pots, and stop digging around established roots once everything has taken hold. If root competition worries you, grow the companions in their own containers and cluster them instead. That is where the wall planter or a few separate pots beat planting everything into one bed, and it also means you can move the whole arrangement when the sun angle changes.

Most of these plants have a second life once the season ends. Sage leaves are at their best fresh and make a good tea, and cutting the plant back regularly keeps new growth coming. Parsley 'Curly Dark Green' (Petroselinum crispum) is the odd one out among herbs because it actually likes fertile soil, and it gets bushier the more you harvest it. Lovage leaves and roots go into salads or the pan, dried cumin seeds season stews and curries, and Hyssop (Hyssopus officinalis) sits in the mint family alongside the Peppermint Buddy Pack. Once you have half a dozen species on the go, the Pot Marker (Zamnesia Exclusive) 5 pcs pack in black and gold earns its keep, because parsley, coriander and chervil seedlings look near identical for the first fortnight.

If you are buying for this season and want the least fuss, we would put the SCARE mix along the sunny edge of the plot and a Cerastium Buddy Pack at the base of the pots, then add a Marigold Buddy Pack in the front row for the insect work and the colour. Come next spring, when you know which corner stays dry and which stays damp, that is the moment to spend on Lavender and German Winter Thyme, the two that will still be there in three years.