If you are an outdoor cannabis cultivator growing in a region where autumn combines wet weather and temperature drops, then it’s more than likely that you have had issues with mold on your weed plants.
However, prevention begins with the right choice of cannabis seed and this article recommends our top 5 mold resistant strains to help give you that essential first line of defense.
You know how it is… you have a wonderful plant in an outdoor space which has performed like a dream through the vegging stage. As it hits flowering, those flower sites erupt and before long the buds become dense and swollen and then… pow! All it takes is a few days of rain and some fluctuating temperatures and suddenly those top buds are contaminated.
There are of course ways to prevent and treat mold when it arrives, and you can get some good outdoor weed cultivation tips on this topic here. However, this article looks at what you can do at the start of the growing process to reduce your risk.
Our first bit of golden advice is to always think ahead when ordering seeds. If mold is an issue, then spend some time to research which plants are best suited for your grow environment ie those seeds which are noted as growing mold resistance weed strains.
Which cannabis strains have the best bud mold resistance?
Generally sativas are the most mold resistant weed strains because of their morphology. Their growth pattern is characterized by a tall structure with well-spaced leaves, providing lots of circulation. Nevertheless, their longer flowering cycle which means a later finish (sometimes as late as early November), does put them at risk from longer exposure to adverse weather.
A sativa dominant hybrid (or a hybrid which produces smaller buds) is often the best way to go, because of the reduced flowering time. Some plants are also bred for resistance qualities too – so it is always worth checking individual strain descriptions.
For mold resistant weed strains check the genetics
The lineage of a plant is also another factor to consider when choosing the right outdoor cannabis seeds to grow to avoid problems with mold. Some cannabis ‘families’ include genetics which are recognized as having increased levels of resistance.
Plants with origins in the Kush, Skunk and Haze families, for example, tend to be more mold resistant, while plants which have a strong presence of White Widow or Northern Lights in their lineage are also known for having good anti-mold qualities.
What types of mold are there?
The main types of cannabis mold are:
- Botrytis – Also known as gray mold, its spores are spread by the wind and it often targets a plant’s vulnerabilities (such as old and damaged parts of the plant).
- White Powdery Mildew (WPM) – This looks like a sprinkle of icing sugar on plant leaves and is a common issue when humidity levels are too high
For more information, read our article on Different Types of Cannabis Mold and Tips to Treat it.
Which cannabis strains are worst for bud mold?
There is no simple answer to this because mold is a product of the growing environment. Nevertheless, those with outdoor weed cultivation experience, will be aware that it is often those big, fat juicy buds at the top of the plant which get mold first. This gives a clue as to which weed strains are more susceptible to mold.
Plants which have a high percentage of indica in the genetics produce fatter, larger buds and because of the indica morphology, these plants are not so good at dealing with humidity and tend to suck up more moisture.
Nevertheless, their generally shorter flowering times are a plus, and some outdoor weed cultivators will take the risk that they will finish before the weather gets too bad.
Top 5 Mold Resistant weed strains for outdoor growing
The following strains are in no particular order of preference.
This list begins with Original White Widow because this strain has an almost mythical reputation for its great resistance to mold. It was hugely popular in the 1990s and its influence has extended since that time. The White Widow in the Paradise Seeds library is IBL (in Bred Line), which means we can trace its lineage right back to the original. Always a recommendation for the outdoor weed cultivation purists looking to grow some classic genetics.
- 2) White Noise
This 2022 strain release may not have the history, but its first outdoor season was accompanied by unanimous approval from outdoor growers due to its high levels of resistance. This strain is a cross between the old school Widow and the popular Cookies strain and the result is a sweet tasting, big yielding plant which is a superb outdoor performer.
- 3) Wappa
While it is the original Wappa which is on this top 5 mold resistant cannabis strains list, the Wappa family also includes Mendocino Skunk, Tangerine Sorbet and the 2023 release, Caramba, which is a terpene rich combination of Wappa
and Gelato 33. With Sweet Skunk in its foundations, good resistance is one of the calling cards of the Wappa family.
- 4) Jacky White
This is another legacy strain to check out which has great mold resistance qualities. In the mix of these formidable genetics are White Widow, Jack Herer and some Northern Lights. It has been a recommendation for outdoor weed cultivators battling to bring home a decent harvest in a mold battle zone for many years!
This sativa dominant strain, which won silver at the 2022 Spannabis Cup, has excellent resistance qualities when it comes to avoiding mold issues. It’s a cross between L. A. Amnesia (also an excellent mold resistant sativa) and Thin Mint Cookies which displays an open structure (meaning good air flow) and vigorous vertical growth.
For outdoor weed cultivation defense from mold in the autumn starts with choosing the right seeds in spring. By selecting the right cannabis seeds for your growing conditions, you can significantly reduce the risks later in the year.
- Wappa3 Seeds: €20.00 Select options
- Chocolate Wafflez
€26.00 – €75.00
- Original White Widow (IBL)3 Seeds: €32.00 Select options
- Jacky White3 Seeds: €32.00 Select options
€26.00 – €75.00
- White Noise
€32.00 – €90.00