When’s the latest you can plant cannabis seeds outdoors?

We are already in May, and many outdoor growers are probably wondering if they’re already too late to plant their marijuana seeds and get the best possible yield. There’s no need to worry, though: cannabis is a plant species that stands out for its high adaptability, so you still have time to germinate your cannabis seeds with the guarantee of a great harvest. We’ll explain why here!

When is the best time to start a marijuana grow? To be able to answer this question, there’s another more important issue that needs to be discussed first: How long does marijuana take to grow out in the open?

Cannabis in an annual plant that develops its big buds between late summer and autumn. Each spring, growers plant their seeds with the hope of producing plants that are both vigorous and hardy during their vegetative stage. As the plants develop, the summer solstice brings a longer period of darkness which sets off the flowering phase. In autumn, the flowers start to ripen before they are eventually harvested.

Therefore, photo-dependent cannabis plants can take between 5 and 6 months (or longer) to fully mature outdoors, whereas autoflowering strains reduce it to about half that time. But this may vary depending on a number of different factors: Are you growing from a seed or a seedling? How’s the climate in your region? What type of strain are you growing? What type of growing techniques are you using? These are only a few of the questions that you’ll need to ask yourself to determine your time limit for planting.

The importance of latitude, climate, and genetics

The time that a cannabis plant takes to grow outdoors depends on the latitude of the region, which is the distance between that region and the equator. For instance, cannabis seeds are usually planted between early March and late May in the northern hemisphere. After a few months, the plants are harvested between September and November.

In the southern hemisphere, the growing season is exactly the opposite: growers start sowing between September and November, so they can harvest between March and May. On the other hand, cannabis growers who live near the equator have the luxury of being able to grow all year round, as there are hardly any variations in the duration of the periods of light and darkness in that area.

When you grow marijuana outdoors, the genetic makeup of your strain also has an influence on how quickly your weed grows. Generally, indicas tend to flower more quickly than sativas, so they finish their cycle earlier. This means that, when sativas are grown in latitudes which are too far north or south, they may not have sufficient time to fully grow due to the earlier arrival of the cold weather.

On the contrary, in the tropics, where a warm climate is the norm, cannabis plants can complete their life cycle much later than in places with extreme conditions of either heat or cold, where they are forced to mature earlier.

Amnesia x Lemon Skunk x Jack Herer

Amnesi-K Lemon

Amnesi-K Lemon is a seed composed of a trio of kings - Amnesia, Lemon Skunk and Jack Herer. This three-way union resulted in a great sativa that fills us with laughter, good vibes and moments of euphoria, with sweet, earthy and super citrussy notes (hence its name). Try it and experience the pleasure of seeing it, smelling it, tasting it and - above all - feeling it.

When is it too late to start growing cannabis outdoors?

You don’t need to worry if you missed the start of the outdoor season by a month or two: you can still obtain a high-quality outdoor cannabis yield, even if you start late (if you plant your seeds in June or even July). Having said that, your photo-dependent strains will have missed part of their vegetative period, which translates into a slightly reduced yield; but its quality won’t be affected.

For outdoor cannabis growers, the months closest to the summer solstice are the best time to plant. During those months, nights are short enough to stimulate vegetative growth but not the flowering buds. One widespread practice amongst outdoor growers in the northern hemisphere is to plant cannabis before the summer solstice (21^st June). From that moment on, the days become shorter and the nights become longer, and cannabis plants keep developing their leaves and branches until the light / darkness ratio reaches the point with longer periods of darkness.

Nonetheless, it is also important to keep in mind that you can still plant cannabis seeds after the summer solstice (which is the longest day of the summer), and you’ll still be able to obtain a decent yield. For growers in the northern hemisphere, germinating their photo-dependent cannabis seeds even in mid-July (or mid-January in the southern hemisphere) would give them around 4 weeks of vegetative growth before about 8 weeks of flowering. This would be around 3 months in total, which is 2 – 3 months shorter than the ideal amount, and which will have inevitable consequences on both size and yield.

When is it too late to harvest outdoors?

This is the other side of the coin; a question that probably depends more on the local latitude and climate rather than on the cannabis seeds themselves. In northern Europe, growers usually harvest in late September / early October, before the arrival of the first cold days of autumn. However, this is based on the assumption that the good weather lasts this long, since there are no guarantees that winter won’t arrive earlier.

In contrast, many growers who live in warm climates with long summers (like the Mediterranean) can harvest their plants in November or even December. This gives them the chance to start an outdoor cannabis grow in late summer and still produce a good yield, even with photo-dependent, long-flowering sativa strains.

When can autoflowering seeds be planted outdoors?

As they don’t depend on the photoperiod to flower, autoflowering seeds can often produce 3 successive outdoor crops per year when grown in regions with a warm climate and a long growing season. The fact that their growth cycle is so fast, in addition to their high resistance, means that autoflowering seeds are a great way to obtain a good yield outdoors after a late start. Their life cycle is around 100 days, so they’re the most convenient option for growers looking to plant cannabis as late as the end of the summer.

The best marijuana seeds to plant outdoors this summer

Besides autoflowering seeds (which can be planted at any time, weather permitting), a late outdoor start calls for photo-dependent strains that are known for their quick flowering and proven resistance to the climate at the end of the season (both in terms of temperature fluctuations and high humidity levels caused by the first autumnal rains).

These are some of the Kannabia varieties that meet these requirements:

• Afrodite: Although this is a sativa-dominant strain, we have managed to shorten her flowering period in comparison to her predecessor, Jack Herer. This has resulted in a highly reliable cannabis plant with a 58 – 62 day cycle, so she’s ready towards the end of September.
• Indica Cream: A 100% indica that will certainly make your life easy. She’s highly resistant to both pests and humidity. With such a vigorous growth and only 50 – 55 days of flowering, she can be ready for harvest by mid-September.
• Big Bull: Despite her super indica character, this is one of the most flexible plants in our catalogue, with a really versatile and adaptive behaviour. With her 55 – 60 day flowering cycle, she’s ready for harvest in the last week of September.
• Diesel Glue: Another all-rounder sativa that doesn’t grow higher than 2 metres outdoors, but that you’ll be able to harvest in mid-October. Ideal for guerrilla growing, so she practically grows by herself.
• Kaboom: An extremely vigorous plant that is especially suited for outdoor growing thanks to her AK 47 lineage. Her flowering cycle lasts between 60 and 65 days, so you’ll get to see what she’s capable of by early October.