Cannabis Growing Outdoors: The 2025 Guide

Why Choose Suzy Seeds for Cannabis Growing Outdoors?

Suzy Seeds has a wide range of seeds for indoor growing that you can also use for an outdoor grow. The seeds are feminized, so you don't have to wait and see if it is a female or male plant. Some outdoor strains have a short flowering time and others take a little longer to reach the end of the flowering phase.

So pay attention when purchasing seeds which outdoor genetics best suits your climate and which growing method you want to use. However, it is also advisable to start planting early in the spring to ensure a good yield and not suffer from mold in your plants.

If you live in the north of Europe, choose a variety with a fast and short flowering time. If you live in a warm southern area, you can also opt for a variety with a longer flowering time.

It's very important to choose the right strain / variety of cannabis. 

In case you are growing weed in an area where it is cold and wet. For example, like the Dutch climate in September and October. Then it is advisable to choose varieties with shorter flowering time and that are resistant to fungi and diseases.   Such as Critical Jack, Hollands Super Bud or Lemon Juice OG. Keep a close eye on the plant, so that you can see what happens in the flowering phase.

Growing cannabis outdoors is the easiest cultivation method, because nature does most of the work. A cannabis plant grown outside, has bigger yield as cultivated indoors.

Suzy Seeds outdoor Autoflowering seeds

The autoflowering seeds are ideal for growing cannabis outdoors. These cannabis plants do not wait for the days to get shorter, but will flower automatically when they are mature. If you start germinating the seed, you will be able to harvest the plant after about three months, depending on which variety.

The autoflowering cannabis plant grows smaller and has a lower yield. But their size makes them less noticeable and the fast life cycle allows you to grow several rounds in one season. When you germinate autoflower cannabis seeds in May, the growth and flowering phases will be in the sunniest part of the year. Also read why you should consider autoflowering cannabis seeds?

Tips & Tricks for Growing Cannabis Outdoors

• Timing is critical when growing cannabis from seed outdoors. The right starting time depends on your strain’s genetics, local climate, and growing environment. Starting too early in spring, when daylight hours are short, can cause seedlings to stretch as they reach for light. This rapid height increase makes plants fragile and prone to snapping, which can severely impact growth. Early flowering is another risk, adding stress and hindering development. To avoid these issues, wait until the risk of night frost has passed—typically around mid-May in most regions. 
• If you need to start earlier, bring your plants indoors at night to protect them from cold temperatures.
  For those eager to begin outdoor growing early, providing extra light and warmth is essential. A heated greenhouse with supplemental lighting works best, but you can also pre-grow in a grow tent or alternate between outdoor and indoor spaces under a lamp to ensure sufficient light hours. Pre-growing helps you cultivate larger cannabis plants with higher yields and allows you to take cuttings for propagation. With Suzy Seeds’ premium genetics and high germination rates, backed by 26 years of expertise, your pre-grown plants are set for success.
• If you pre-grow early and your cannabis plant reaches a suitable size, you can take cuttings in April or May to propagate your favorite strain. Cuttings can be taken until the second week of flowering, but they’ll need to be moved indoors to root and grow, as outdoor conditions won’t support further development at that stage. These cuttings, often called clones, share the same phenotype as their mother plant, ensuring consistent quality and traits—a benefit of Suzy Seeds’ carefully selected genetics.
• To optimize flowering for your outdoor cannabis, consider a darkening technique. This involves giving your plants 12 hours of sunlight followed by 12 hours of complete darkness to trigger flowering. You’ll need to grow in pots so you can move them into a dark shed, or use a lightproof tent or box to cover the plant. Complete darkness is crucial—any light leaks can stress the plant and disrupt flowering. Start darkening in mid-June, and your plants will flower in July and August, allowing for an ideal harvest timeline. If you begin darkening in the third week of July, you only need to continue until the second week of August, as natural daylight hours will be short enough afterward. Maintain this schedule until flowering is complete to avoid stressing your plants.
• For the best results, place your cannabis plants in a sunny, well-ventilated spot to prevent mold growth.
• Water them with rainwater and use high-quality nutrients to support healthy development.
• With Suzy Seeds’ reliable seeds, you can trust in consistent growth and exceptional harvests.

Growing your own cannabis outside is a pleasant activity. Gardening gives peace of mind and has a proven therapeutic effect. With a somewhat normal summer, an outdoor cultivation is always a success. Because you know what you are consuming for every bud that you grow yourself and you do not have to buy it for a high price in the coffee shop / despensary.

Regional Tips for Growing Cannabis Outdoors

When growing cannabis outdoors, your region’s climate plays a big role in your success. At Suzy Seeds, we’ve been helping growers thrive for 26 years, and we know how to adapt to different environments. Here are expert tips for cultivating in the UK and the US, tailored to their unique conditions, so you can make the most of our premium genetics.

Growing Cannabis Outdoors in the UK

The UK’s shorter summers and unpredictable weather can be a challenge, but with the right approach, you can still achieve a fantastic harvest. The key is timing and strain selection. Start your outdoor grow in late May, after the last frost, to give your plants a head start—temperatures should ideally be above 10°C at night. The UK growing season typically ends by late September, as cooler, wetter conditions set in, so choose fast-flowering strains to beat the autumn chill.

Our Lemon Juice OG and Northern Light are perfect for the UK climate. These strains, backed by Suzy Seeds’ high germination rates, are resilient to cooler temperatures and can finish flowering in 8–10 weeks, ensuring you harvest before the weather turns. To combat the UK’s frequent rain, ensure good airflow around your plants and use a well-draining soil mix to prevent mold. A sunny, south-facing spot is ideal to maximize light exposure during the shorter summer days.

Growing Cannabis Outdoors in the US

The US spans diverse climate zones, from the humid Southeast to the arid Southwest and the temperate Northeast, so your approach to growing cannabis outdoors will vary by region. With Suzy Seeds’ reliable seeds, you can tailor your grow to your local conditions for a bountiful 2025 harvest.

Advantages of an outdoor grow

• Cannabis grown outdoors has a longer growing period and will grow a lot taller than growing indoors. As a result, the yield per plant is a lot higher. With a single plant you can get just as much yield as from a 1m² grow tent with a 600 Watt HPS lamp.
• Outdoor weed grows and blooms gradually. This gives the plant more time to develop terpenes and cannabinoids, making it more suitable for medicinal use.
• With an outdoor grow you don't have to buy an expensive grow installation and you have no energy costs. Light, ventilation, heating and rainwater are free. Even on a cloudy day, the light intensity is just as high as an average grow light.
• Nature offers the plant natural protection against pests, vermin, insects, etc.

Disadvantages of growing cannabis outdoors

• The time in our outdoor growing season is limited. So you can't harvest all year round. You have to see that in one season you grow your stock of weed for the rest of the year. Keep a close eye on your calendar.
• You have to take into account the climate in which you live. Not all cannabis strains are suitable for outdoor cultivation in every climate. If it is early autumn, then a plant with a long flowering period will not be of much use. Without darkening or flowering indoors, the buds will not mature enough and the yield will be disappointing.
• If you are going to grow weed outdoors, you do not have full control over all factors. You may have the perfect spot in your garden, but you have no influence on the sun, wind, humidity and temperature and you have to leave everything to mother nature.