Top 10 Mould-Resistant Cannabis Strains

As cannabis buds mature, they can become quite susceptible to mould. This problem particularly affects outdoor growers in Northern climates, where weak, late-season sun prevents adequate evaporation of moisture. It can also affect indoor and greenhouse grows with poor air circulation for the same reason. Warm, humid climates also provide ideal conditions for mould to develop.

Mould or bud rot can be heartbreaking. It is a fast-spreading pathogen transmitted via spores that can reduce glorious buds to mush in a matter of days. A number of species of cannabis are naturally mould-resistant, mainly due to heavy resin production. Apart from providing the delicious compounds that get humans high, resins play the primary role of protecting cannabis from diseases, pathogens, and animal predation. These 10 strains are at the top of the mould resistance list, presented in no particular order.

#1 ELEVEN ROSES BY DELICIOUS SEEDS

Eleven Roses was a deliberate breeding attempt to improve the in-house, multi-award-winning favourite Sugar Black Rose. With resounding success! Crossing a Sugar Black Rose female with an Appalachian Kush male produced a heavy resin-producing plant. With a THC quotient as high as 25% from uniquely coloured phenos, this strain takes on autumnal hues as it matures.

Under grow lights, there is little lateral branching, with plants producing a single impressive cola. Outdoors, there is substantially more lateral branching. A single, reasonably-sized plant of 1.5 metres can produce up to a kilo of bud. The intense resin production not only makes for a smoke that will satisfy the most discerning cannabis fan, it makes this strain very mould resistant.

#2 PEYOTE COOKIES BY BARNEYS FARM

Crossing the well-respected Peyote Purple with the legendary Cookies Kush has produced this sturdy mould and mildew-resistant strain. Displaying typical hybrid hardiness, Peyote Cookies is a trouble-free grow indoors or outdoors. Flowers are dense and resinous, turning blush pink and red when mature.

Thick resin production means Peyote Cookies has the benefit of mould resistance, along with excellent yields and a unique flavour profile. First impressions of sweet guava are quickly followed by vanilla and fresh ground coffee. After the flavour sensation, there is a deeply relaxing and long-lasting effect.

#3 MEXICAN SATIVA BY SENSI SEEDS

There is no need to fret about maturing times with this sativa hybrid. Some Durban and a quick-flowering, heavily resinous Pakistani hash plant have been used to reduce the long tropical flowering time. The resin production is impressive, and makes Mexican Sativa a mould and mildew-resistant favourite for indoor and outdoor grows alike.

The robust growth, heavy yields, and enticing flavours of this plant keep growers coming back for more. Earthy and woody bouquets mingle with sandalwood incense, which then give way to sweet fruit and florals. Heavy yields are an added bonus, and it is recommended to tie the plant down outdoors. This prevents the large Christmas tree shape, encouraging lateral bud development instead.

#4 S.A.D S.1 BY SWEET SEEDS

Sweet Afghani Delicious S.1 is a pure Afghani strain crossed with an inbred Black Domina. This is a 90% indica strain that displays the resin production for which both parents are famed. This heavy resin development helps prevent mould and mildew, while inducing a pleasant, body-numbing stone.

This plant is very attractive, boasting a dark green colour with a hint of purple. The buds look bright orange against the early evening hues of the foliage. THC is 15–20% from thick, knotted flower clusters on robust branches. It does take a while to mature at 9 weeks, but the wait is well worth it with 500g/m² for the patient indoor grower.

#5 SHERBET QUEEN BY ROYAL QUEEN SEEDS

Just by looking at this marvelous plant, you will be in awe. Covered in trichomes and orange pistils, Sherbet Queen is the perfect nightcap after a long day at work. Thankfully, given its abundance of resin, this plant laughs in the face of mould, churning out terpenes and cannabinoids as a defence mechanism.

This indica-dominant hybrid brings up to 24% THC to the table, so it’s a strain deserving of your respect. It produces a pleasant body high, but it won’t leave you incapacitated like other heavy indicas. Instead, you’ll feel its uplifting traits shine through without excess stimulation.

As a grower, you’ll appreciate its indoor yields of up to 550g/m². And it only needs around 9 weeks to flower.

#6 A.M.S BY GREEN HOUSE SEEDS

A.M.S or Anti Mould Strain is a fruit and citrus delight created from a Swiss Indica and a Swiss sativa. It is an interesting blend as it contains 1% CBD, .07% CBN, and up to 19% THC. This combination makes for a recreational toke with a twist, or some excellent medicine. The anti-mould properties also make it extremely resistant.

Ideal for outdoor growers in humid climates, AMS is also a heavy-yielding plant. It can produce 700–800g/m² indoors after 8 weeks of flowering. Outdoors yield are just as impressive. A late September harvest will provide 800g/plant of the sticky icky. Leaving this strain an extra week makes the bouquet and flavours deeper and more complex. There are two dominant phenotypes. Choose the indica for best results.

#7 FRISIAN DUCK BY DUTCH PASSION

Mauve hairs and unusual leaf shape make this heavily resinous plant a unique-looking strain of marijuana. A cross of Frisian Dew and the Australian Ducks Foot has created a strain that barely resembles cannabis. During the vegetative phase of growth, the leaves of Frisian Duck are webbed and lack that characteristic cannabis silhouette. This is an added benefit for the stealth grow as it doesn’t really look like weed.

However, it certainly packs a punch like weed once ripened to perfection. Frisian Duck is a robust and easy-to-grow indica-dominant strain that resists pathogens very well. Indoors, she is ready in 8 weeks, while the outdoor grower will be harvesting in early October. Yields are average, but the effects are as unique as the leaves.

#8 STRAWBERRY LEMONADE BY BARNEY'S FARM

For those who love their daytime tokes, this could be a new favourite. A sativa-dominant hybrid, Strawberry Lemonade’s effects will leave you creative, focused, and eager to get stuff done. THC levels are moderate, at 20%, which means you can toke on this one without losing your motivation. 

Strawberry Lemonade plants need up to 10 weeks to flower, but the yields on this one are massive. Indoor growers can look forward to up to 700g/m², while outdoor growers can net more than a kilogram per plant. Be sure to reserve some space in your drying room, because you’ll need it. Worried about your stash falling victim to mould and rot? With the proper care, these resinous, resilient buds should present no problems. Just make sure to follow the proper drying and curing protocol!

#9 BLUE DREAM BY ZAMNESIA SEEDS

Everyone loves a strain that provides a pure uplifting feeling. And Blue Dream is one of the most capable of satisfying this desire. An 80% sativa boasting around 19% THC, don’t let its moderate potency fool you; Blue Dream is beloved for delivering a mind-body high unlike any other. Expect fresh ideas and inspiration, but toke too much, and this sativa may send you into a slumber.

In the grow-op, Blue Dream requires some attention, but it's still viable for amateurs looking to achieve a personal stash. If you keep conditions optimal, you’ll be rewarded with up to 350g/m² indoors and medium yields outdoors. Plants peak at around 1.5 metres, so you can grow this cultivar in a wide range of environments with a little training.

A quick Google search will tell you that Blue Dream is widely deemed mould and pest-resistant across the cannabis community, and this is one of the reasons it’s remained so popular among growers of all levels.

#10 BLUE FOREST BERRY BY GROWERS CHOICE

Is it named after a blue forest or a blueberry from the forest? It doesn’t really matter. This extraordinarily hued example of cannabis is tinted many shades of violet and deep blue when reaching peak maturity. This very compact sativa-dominant strain is easy to grow, and the reward is jars of fruity, Haze-flavoured nuggets. Blue Forest Berry’s resin production is high, giving it superb mould and pest resistance.

Sativa dominance means an 8–10 week blooming time indoors, with an October harvest outdoors. Yields are high in both instances, and cooler climates can expect some truly marvellous colours. The effects and yields are world-class, but this plant is worth growing if purely for the remarkable aesthetics.

Growing mould-resistant strains with care

These may be mould-resistant strains, but that doesn't mean they don’t need ample care. As a cultivator, part of your responsibility is to ensure that your precious plants are growing in a healthy environment in which they can thrive. That said, we could all use a little help here and there, so there’s nothing wrong with picking a strain that offers some extra protection. At the end of the day, you’ll be the one reaping the fruits of your labour.

Adam Parsons

Professional cannabis journalist, copywriter, and author Adam Parsons is a long-time staff member of Zamnesia. Tasked with covering a wide range of topics from CBD to psychedelics and everything in between, Adam creates blog posts, guides, and explores an ever-growing range of products.

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