McKennaii Grow Kit XL 2100 ml – GetMagic® | Magic Mushroom Kit

Why choose the McKennaii XL?

McKennaii is the most potent strain in the GetMagic® range — and in the 2100 ml XL format, a single kit produces enough for a long series of powerful sessions. Nearly double the colonised substrate means bigger flushes, heavier individual mushrooms, and significantly more material per grow. Because McKennaii is so potent, you’ll use less per session — making the XL kit last exceptionally long.

McKennaii psilocybe cubensis is a lab-cultivated strain developed by Dutch mycologists and named in honour of the legendary ethnobotanist Terence McKenna (1946–2000). It was designed to push the boundaries of cubensis potency.

The mushrooms produce medium to large fruiting bodies with caramel to deep brown caps (30–70 mm) that are often wavy or bulbous in shape, set on thick, dense stems (50–140 mm) that bruise heavily blue-green — a visual indicator of high psilocybin content. In the XL kit, the extra substrate allows the strain’s characteristically dense fruits to grow even heavier.

The experience is intense and deeply immersive: strong geometric visuals, vivid colour enhancement, and a heavy, philosophical headspace. Effects tend to onset faster than average cubensis strains. McKennaii is not recommended for beginners — start with Golden Teacher or Mexican if this is your first grow.

Growing the McKennaii XL

The setup is identical to the 1200 ml kit — same grow bag, same method. McKennaii colonises at a moderate to fast pace, so the XL substrate fills efficiently. Keep the temperature at 24 °C and expect pinning within 10–16 days.

The XL kit produces noticeably heavier individual mushrooms and denser flush trays than the standard size. Handle your harvest carefully — McKennaii bruises heavily, and the intense blue-green discolouration is completely normal and a sign of potent fruit.

McKennaii — strain specifications

Frequently asked questions

What’s the difference between the 1200 ml and 2100 ml XL kit?

Same strain, same method, bigger box. The XL contains nearly double the colonised substrate, which translates to higher yields (400–800 g vs. 200–400 g), heavier individual mushrooms, and typically an extra flush or two. Because McKennaii is the most potent strain in the range, the XL is exceptional value — you’ll use less per session, so a single kit lasts a very long time.

What yield can I expect from this 2100 ml XL kit?

The McKennaii XL typically produces 400–800 g of fresh mushrooms across multiple flushes. The strain produces dense, heavy fruiting bodies that weigh more than they look. Actual yield depends on temperature, humidity, and hygiene during the grow.

Why do my McKennaii mushrooms bruise so much?

McKennaii bruises more heavily than any other strain in the GetMagic® range — the intense blue-green discolouration is caused by the oxidation of psilocybin and psilocin when the flesh is damaged. It’s actually a positive sign: heavy bruising correlates with high potency. Handle your mushrooms gently during harvest, but don’t worry if they turn blue — it’s completely normal and doesn’t affect quality or safety.

Be sensible

Check out the responsible use page for more information on do’s and don’ts.