secure connectionOur 45 Day Autoflower Strains category includes cannabis varieties designed for speed and efficiency. Ideal for US growers looking for quick harvests with reliable, high-quality results.
10 seeds
Looking for fast-growing auto-cannabis strains like Ruderalis? Weed Seed Express’s collection of 45-day autoflower seeds offers some of the best in the market. These seeds start flowering in just 45 days and provide quick harvests, high yields, and excellent-quality, dense buds. It is perfect for growers who want speedy results without compromising on potency. Browse our collection of the fastest autoflower strains for your next indoor grow!
45-day autoflower seeds are cannabis strains that take just 45 days to complete their flowering stage, regardless of the light schedule. This makes them much faster than regular autoflower seeds, which usually take 55–75 days to flower. However, while the flowering period is quick, the total life cycle, including germination and vegetative growth, may last between 70–75 days. 45-day autoflower seeds are perfect for growers who want a quick harvest, as they go from seed to harvest much faster than photoperiod cannabis strains. They are easy to grow, resilient, and can produce good yields quickly.
Here is a step-by-step guide on how to grow premium autoflower seeds:
Start by using a well-draining soil mix like Pro-Mix. It should be light and airy to allow the roots of the cannabis plant to grow freely. You can mix it with a 50/50 blend of Gaia Green Power Bloom and All-Purpose for an ideal growing medium for your marijuana seeds. Alternatively, you can make your own plant mix from the start by mixing coco coir, organic compost, perlite, and peat moss.
Keep your grow room temperature between 65-75°F (18-24°C) for optimal growth. During the vegetative stage, maintain a humidity level of 50-60% and reduce it to 40-50% as the plant matures to avoid mold.
Autoflowers are low-maintenance in terms of nutrients, making them ideal for novice and experienced growers alike. A pre-mixed soil with some fertilizer might suffice for most of the growth cycle. You may need to add nutrients gradually as the plant grows, but avoid overfeeding early on and only feed the plant when needed.
Autoflowers need around 18 hours of light and 6 hours of darkness daily. Use a good grow light (LED light is recommended) and keep it at a safe distance to avoid burning the cannabis plant.
Autoflowers are fast-growing and can be sensitive to excessive stress. Avoid training techniques like topping (cutting the main stem) or filming (making small cuts to encourage branching), as these can significantly slow down growth. If you want to manage the plant's shape and see the best results, use LST. This involves gently bending or tying down branches to encourage lateral growth and maximize light exposure. You can also do the same by purchasing CBD autoflower seeds.
Autoflowers have many benefits, but the most obvious one is their quick growth. They usually take just 8–12 weeks from seed to harvest, depending on the strain and growing medium used by experienced growers. Here are other benefits:
Autoflowers don’t rely on light cycles to start flowering. This means you can grow them at any time of the year, whether indoors or outdoors. Plus, with their short lifespan, you can grow and harvest multiple buds per year to get more yields.
Autoflowering plants tend to grow small and bushy, usually growing under 1.2 meters tall. Their size makes them ideal for growers with limited space, like balconies or small grow tents, or those looking for stealthy cultivation (indoors and outdoors). Also, they require less maintenance because they don’t need pruning, trimming, or extensive training.
Autoflowering strains are simple, require minimal maintenance, and have fast growth cycles, which makes them attractive to first-time growers. They don't need specific light schedules to start flowering, and you can easily predict their growth. All you need is the right grow techniques to get consistent, high-quality yields off your autos! If you want to do a test run first, then you can opt to buy cheap autoflower seeds.
Typically, 45-day autoflower seeds take 45 days to complete their flowering period. However, the total growing cycle, from seed to harvest, usually takes about 60 to 75 days (8 to 10 weeks). The plants usually start flowering 2 to 4 weeks after germination, and the quicker they start flowering, the faster they will be ready for harvest.
The best 45-day auto-flowering strains for beginners are Amnesia Haze x Blueberry, Sweet Tooth, and Northern Lights. Most of our customers in this category love these strains because of their excellent yields, fast growth cycle, and simple growing requirements. You can also consider OG Kush for its unique qualities or check out our entire collection.
Big Bud Auto is an Indica-dominant autoflowering seed with a mild THC level (22% THC). It’s easy to grow and best for anyone looking to get high-quality yields with minimal effort. This strain (when planted under the right conditions) produces up to 500g/m² indoors and 120g per plant outdoors. It is compact (within 3 - 5ft), pest-resistant, and completes its growth cycle within 6-7 weeks!
Cherry Pie Auto is another great choice for beginners. It’s easy to grow, has high fungal resistance, and induces an energetic, uplifting high. What’s more? It yields as easily as it grows. When planted indoors, it pumps out up to 450g/m² indoors and 600g per plant outdoors. Plus, the grow cycle spans between 6 - 8 weeks from seed to harvest.
If you’re looking for a strain with potent effects, a good terpene profile, and a fast flowering stage, then Black Jack Auto is the real deal. This sativa-dominant strain has a berry-sweet aroma, produces (really) dense buds, and produces high yields—up to 550g/m² indoors in just 6-7 weeks! It's perfect for beginners and experienced growers looking for the fastest cannabis strains with great potency and aroma.
You can purchase the best and fastest autoflowering cannabis seeds from Weed Seed Express. Our digital-first platform lists several high-quality strains with strong genetics, perfect for anyone who wants a quick turnaround without compromising on quality.
Top-Quality Seeds We handpick our strains (with the best, stable genetic lineage) from reliable breeders to ensure consistency in plant growth, quality, and potency. We have over 200 high-quality marijuana strains listed on our website for all growers' profiles – whether you’re a beginner or an experienced grower looking for the best cannabis plants.
We offer a 96% germination guarantee on all our seeds. We also include free seeds in our 5—and 10-seed packs to increase the germination rate to 100%! Fast Shipping Fast and discrete shipping is our forte. Over the years, at Weed Seeds Express, we’ve maintained a reputation for delivering orders to locations within and outside the US. Most orders are delivered within 11 days or less (domestic US orders are often quicker). You can also track your order at every step of the way with our Track and Trace shipping for guaranteed delivery.
The names say it all: auto flowers flower on their own, while photoperiod plants depend on light to start flowering. Autoflowers start flowering based on age, not light, and grow faster, usually in 8-10 weeks. Photoperiod plants need 12 hours of light and 12 hours of darkness to start flowering, taking longer to grow. Autoflowers are quicker and easier to grow, while photoperiods give you more control over growth and can produce larger harvests. In simple terms, the main difference between autoflower and photoperiod strains is what triggers flowering and the growth cycle period.
45-day autoflower strains usually take around 55 to 70 days from seed to harvest. They begin flowering after 2 to 4 weeks of vegetative growth, and the faster they start flowering, the quicker they reach maturity.
Choosing feminized autoflower seeds is recommended because they guarantee that only female plants will grow. Female plants are the ones that produce the desirable buds (with high THC content), while male plants can pollinate females and produce lower-quality buds. With feminized autoflower seeds, there’s no need for sexing or culling male plants, making the growing process easier and more efficient. This ensures a higher yield of potent buds with minimal hassle, especially for beginners.
