Best Nutrients for Autoflowers

Welcome to the revolutionary and exciting world of growing autoflowering cannabis seeds. Whether you are a first-timer or an experienced photoperiod marijuana cultivator, learning how to grow autoflowering strains (aka autos) promises a rewarding venture for any cannabis grower. 

Autoflower seeds are relatively easy to grow compared to their light-sensitive sister strains. Their life cycle is guided by a certain amount of time instead of hours of light cycle changes. Auto’s are hardy, robust small plants that don’t require the same diligent care as feminized photoperiod strains.

Ruderalis genetics provide these compact plants with everything they need to survive. In fact, autoflowering cannabis strains will actually grow just fine when left alone.

With that stated, however, there are some practical measures to follow, guaranteeing an ample harvest when growing autoflowering cannabis varieties. One of the most important criteria for a prized autoflower harvest is learning how to dial in a beneficial nutrient program in your grow room.

How do Nutrients Affect Autoflowering Strains?

If you have ever looked at a commercial fertilizer label, you have undoubtedly seen the three letters NPK printed together. Nitrogen (N), Phosphorous (P), and Potassium (K) are the three main macronutrients found in many pre-packaged nutrient products. They are also the three main elements required for your autoflowering marijuana plant to thrive.

Typically, you will also notice a series of numbers relating to the percentage amount of each element present in the product. For instance, a 10-5-5 nutrient label means that there are 10 parts of N, 5 parts P, and 5 parts K contributing to the formula. All three of these elements are essential to the development of your autoflowering seed, but each one plays a different role during various life stages.

Nitrogen is the driving force for vegetative growth. It feeds the plant, producing energy for photosynthesis to develop branches, stems, and leaves. Nitrogen happy plants have a dark, earthy green color when proper doses are applied. Too little N in the veg state, you will see yellowing leaves beginning with lower, old-growth.

Phosphorus is necessary to promote healthy root growth during the first few weeks of the autoflowering seed’s life. This nutrient helps synthesize proteins and carbohydrates, promoting energy transfer within the plant. Without sufficient P in the vegetative phase, auto plants quickly exhibit stunted growth and discolored leaves.

Finally, potassium is required to stimulate early growth as it improves water transfer within the autoflowering plant. K strengthens plant tissues providing sturdiness to stalks and leaves while helping the auto build resistance to disease. Nutrient deficiencies of this essential element during vegetative growth will produce a sickly, poorly developed plant.

How to Dose Nutrient Levels for Autoflowering Plants

While these macronutrients are essential during all growth cycles, the dosing requirements of each element vary as the autoflower evolves through its life cycles. As stated above, nitrogen is the heavy hitter during vegetative growth. A 10-5-5 nutrient formula during veg growth will provide adequate levels of all three elements to your autoflowering plant during early development.

However, as the auto swiftly enters the pre-flower stage, changing the nutrient ratios to 5-10-10 communicates to the plant to redirect energy flow. Instead of focusing on growing leaves and stems, energy now should progress to building the flowering system.

This stage is where phosphorus and potassium brilliantly shine since they are responsible for bud site development and flower density. Elevating ratios of P and K as the plant begins pre-flowering sends extra sugars up into the delicious flowers. Reducing nitrogen while increasing phosphorus and potassium levels in your nutrient recipe at this change in growth development stimulates a bountiful crop full of big buds in the flowering stage.

Most commercial cannabis fertilizer ratios are formulated for photoperiod plants which depend on hours of darkness. Recommended doses found on nutrient labels are relatively high for these light-sensitive heavy feeders. On the other hand, autoflowering plants with their resilient cannabis ruderalis genetics do not need as much food.

Autos only require a fraction of the suggested dosage amount of nutrients. Start with low amounts, between 1/8 – 1/4 of the recommended dose, when applying nutrient formulas to your autoflowering plant. Carefully watch the plant as it responds to the recipe, incrementally increasing levels as the auto reacts positively to the additional food.

Due to its short life cycle, if you hit an autoflowering plant with too high of a nutrient solution, it will burn the root system. Overfeeding often results in nutrient burn which causes irreparable damage as the fast-growing auto has a small window of time for recovery.

Do Autoflowers Need Other Nutrients?

All cannabis plants, whether photoperiod or autoflowering varieties require specific nutrients in their diet for maximum production. As we discussed, NPK are the big players in your nutrient program, crucial to the plant’s success. Secondary elements such as Calcium (Ca) and Magnesium (Mg) contribute to the general overall health of the plant.

Additionally, trace elements such as Copper (Cu), Boran (B), Zinc (Zn), Iron (FE), and other minerals help maximize an autoflowering plant’s development by lending support to the macronutrients. They are referred to as trace elements because the percentages of these minerals found in commercial fertilizers are relatively small. However, they also are essential to the auto’s growth development.

Some, but not all, cannabis nutrient products contain both secondary and trace elements in their formula. Always check the fertilizer label for the addition of these vital compounds when choosing the best nutrient package for your autoflowering cannabis plant.

How do Growing Mediums Affect Nutrient Supplementation?

Probably the easiest way to grow an autoflower seed is to plop it in the middle of a 20-litre pot filled with lightly amended living soil after germination. Add some perlite to the potting soil to allow for good drainage. Give just enough pH balanced plain water to keep the area around the autoflower seedling moist to promote root growth.

Between the nutes found in the potting soil and the seed’s internal nutritional storage, many autoflowering strains will need very little nutrient amending at the beginning of plant life. As they blast through the vegetative stage within a couple of weeks, a premium light potting soil mix providing adequate nutrients will eliminate any worry of feeding the auto during this time.

As the autoflowering plant quickly progresses into the flowering phase, a gentle boost of phosphorus and potassium will promote massive bud growth development. Slowly increasing levels of P & K as the plant matures further ripens the flowers into thick, dense buds covered in crystal trichomes.

When growing autoflowering seeds in hydroponic or soilless substrates, the nutrient application is a bit more intensive. Because these mediums are unable to hold nutrients within their composition, develop a solid plan for a steady nutrient schedule. Start vegetative nutrient supplementation very light, slowly increasing levels as the plant responds. Make sure to keep the nutrient solution at pH levels between 5.5 and 6.5.

When the autoflowering marijuana plant begins showing signs of pre-flower, slowly decrease veg nutrient levels while increasing bloom food during the same intervals. This incremental change eliminates nutrient overload giving the plant time to adjust to the new feeding recipe.

A Well-balanced Nutrient Program Ensures your Success Growing Autoflowering Strains

While autoflowering strains were once looked down upon as low yielding cannabis varieties, dialing in a beneficial nutrient schedule unwraps that myth. Recent autoflowering cannabis genetic advancements, in addition to science-driven nutrient formulations, have raised the bar regarding the outcome of the autoflower’s performance.

Learn more about growing autoflowering marijuana strains:

– Are Autoflowering Strains Potent?

– How to Increase Yield of an Autoflowering Cannabis Strain

– When to Harvest an Autoflower Strain

– Autoflower vs Photoperiod Strains – How Do They Differ?