The Baffling World of Bloom Boosters!

In every human endeavour we should always strive for excellence, and there is always many different routes to achieve it. We are constantly searching for that extra ‘edge’; the hidden advantage over our competition.

In the hydroponics industry this is generally sold in the form of ‘Bloom Boosters’ or generative growth enhancing products. There’s an enormous range of products that fall into this category. Some are scientifically proven to excel whilst others are nothing more than badly bottled snake oil. In this article I outline the good, the bad and the downright ugly about achieving those ‘monster yields’.

Fertilisers promoted for increasing floral growth have historically been utilised in the ornamental flower industry and in almost all varieties of fruit and vegetables. These products can generally be classified into three different categories: PK based, organic bio-stimulants and synthetic PGRs (Plant Growth Regulators). Purchasing these products can be a little confusing and problematic for the consumer as many contain a mixture of several different types of growth enhancers, and not all labels are necessarily 100% accurate or truthful, but more on that predicament later.

The biggest market in Australia for bloom boosters is for hobby hydroponics and small commercial users. These magical bottles are predominantly PK based but in reality, the PK isn’t actually ‘boosting’ your bloom. So why is there such a large demand for these products?

To understand this blossoming market we first need to investigate the physiological and nutritional demands of the plant. We understand that florae utilise different ratios and quantities of mineral nutriment during the different stages of growth and according to their environmental conditions. The hydroponics industry is tragically guilty of inaccurately marketing that drastically increasing phosphorus and potassium ratios during floral growth will massively intensify flower sites and overall floral mass.

In reality plants biologically require a complete balanced profile of macro and trace elements throughout all growth stages. Inadequate or excessive quantities of any required macro or microelement would negatively affect plant growth. In technologically advanced commercial tomato production the NPK ratio is precisely adjusted by analysis and monitoring of plant tissue. During generative growth the ratio reduces Nitrogen and increases Potassium delivered to the plant. This fine- tuning occurs according to the changing light levels and the different stages of plant development. Earlier in the season, the plant is predominantly developing vegetatively and the increased nitrogen allows for the crop to more efficiently utilise the high light conditions.

The correct use of PK products is a hotly debated topic, and there is no unanimous answer for every situation. It’s widely accepted that phosphorus and potassium are used in fluctuating quantities for different developmental functions within the plant at each stage of growth. During the earlier and later stages of floral expansion, crops have a slightly increased demand for phosphorus and potassium, which aids in root growth, flower set and fruit bulking. Recent research also indicates an increase in Iron (Fe) is beneficial in the middle stages of flower. That being said, it’s definitely not a case of ‘more is better’ as some hydroponic retailers may have you believe. Phosphorus and potassium toxicities can easily and quickly occur and can be very difficult to remedy. Most leading international hydroponic nutrient companies have accurately calculated nutriment regimes providing for the correct ratios throughout the different stages of growth. It’s always advised to follow appropriate feed charts with a ‘less is more’ approach, and learn to read what your plants are telling you as they develop.

So how do we acquaint PK products alongside the bio-stimulants in common bloom boosters?

By ensuring you’re providing adequate nutriment including delicate adjustments to the NPK ratio, you’re giving your plants the best chance to reach their genetic potential. However by including various organic or synthetic ingredients, we can begin to manipulate the genetic limitations of the plant in our favour.

Organic bio-stimulants are rapidly gaining popularity with both soil and hydroponic growers. As we increasingly understand the interactions between organic nutriments, the plants rootzone and mycorrhizal/bacterial life, new products are giving growers increases in both quantity and the quality of their yield. Ingredients such as amino acids, enzymes, guanos, and complex sugars can be successfully used in almost any situation as they naturally and gently encourage increased floral growth through various physiological changes in the plant. Amino acids incite enzyme production and promote the natural breakdown of nutrients within the medium for increased plant consumption. These organic bloom boosters may also include a variety of biological by-products such as compost tea, worm juice, rock phosphate or naturally occurring plant hormones. Globally these practices are proving more sustainable and giving farmers impressive results without hazard to the plant or their environment.

Generally as organics break down into their medium and interact with the plant in a more natural fashion, they also encourage greater beneficial bacteria, trichoderma and mycorrhizal activity to aid in overall plant development. It’s worth discussing with your local hydroponic retailer about the base ingredients and supplier of organic bloom boosters, as some brands tend to lack quality control in the manufacturing process.

Which leads us into the ugly side of floral enhancement – synthetic PGRs and some seriously suspicious labelling practices.

A huge market exists for products that can promote unnatural growth, albeit with an assortment of dire consequences. Many of these products are sold over the counter and some from behind dusty closed cupboards; few contain any genuine warning labels, occasionally stating in small text “For growth control of container grown ornamentals only.” Commonly recognized as PGRs (Plant Growth Regulators) these commodities are peddled by retailers ‘to stop vertical growth’ or ‘to initiate earlier flowering with heavier fruit set’. In Australia, it’s possible to register these products with the APVMA but many manufacturers don’t bother with the effort or the expense.

Over the past century, commercial farmers have used PGR’s in a wide range of fruit and vegetable crops but only recently are we beginning to understand the resulting health and environmental harm. The most popular in the current market generally contain a combination of paclobutrazol, daminozide or chlormequat chloride. When used effectively, they inhibit the natural plant hormone gibberellins, which is responsible for cell elongation and cell division. This limits height and internodal length. Fruit and flowers density is drastically increased and paclobutrazol even improves mould and fungi resistance. However for all of these ‘benefits’, there is an abundance of negatives to follow.

Firstly, the quality of the end product is drastically reduced. The impacted flow of gibberellins also reduces essential oil and resin production, reducing the flavour and scent of fruit and flowers. It can also result in drastic mutations to the plant. The far more worrying aspect of these products is the damage to user and consumer health. In the United States, all three of these PGR’s are illegal to use on plants grown for human consumption and completely banned from sale in several states. Daminozide is listed as a human carcinogen; chlormequat chloride has been linked with developmental problems and paclobutrazol has negative effects on the reproductive system and causes foetal malformations in rats. Paclobutrazol also has low mobility and low volatility so it lingers in soil and can contaminate a growing medium for years without degrading.

Ominously, even the registered products contain industrial/technical grade ingredients that can be just 95% purity. The remaining 5% can contain toxins, heavy metals, preservatives or toxic adulterants. More concerning is the subversive market of unregistered PGRs with no real quality control, labelling or adequate directions for use, but that’s a topic for another day. While the registered PGR’s are clearly bad, there’s currently a demand for the product in the market and suppliers will continue to meet it. If you still choose to use these products because it’s the only way you can get that heavy harvest, please try to investigate safe dosing and flushing practices, and relevant withholding periods.

So I’ll finish with the question you’re all asking, what’s really the best ‘bloom booster’ to get me a high quality and quantity harvest?

Well that my friends, depends entirely on you! Different techniques of cultivation will be more or less effective with certain products. If you’re growing in soil or soil mixes, it’s much more worthwhile to use organic blends that will improve your soil over time. Always talk with the friendly hydroponic retail staff, they know the new and innovative products, but always be sceptical for anything that seems too good to be true. I personally recommend picking a reputable nutrient manufacturer and sticking with their scheduled regime, they have calculated the ideal feeding requirements and balanced the distinctive components in different bottles to all work beautifully together.

It’s also worth noting that commercial crops can be ‘steered’ into stimulating increased vegetative or generative development. Steering a plant involves correctly controlling complete external and internal plant growth factors. This includes the environmental conditions (temperature, humidity, growing medium, light intensity, timing, quality and more) and the plants internal growth patterns through nutriment, dosage, natural and promoted hormones and initial plant genetics. Rather than looking for that ultimate product, firstly ensure you are correctly steering your plant towards a beautiful, bountiful harvest!