Best Liquid Plant Feeds – Which One?

Liquid feeds are fertilizers that are applied when watering your plants. This includes both concentrated liquids that you dilute in water and granules that you dissolve. You can use them on pots and borders for instant pickup for your plants. If you’d rather add Controlled release fertilizer You can still use liquid feed for your pots at the end of summer Controlled release fertilizer runs out.

Liquid feeds usually have a different nutritional balance than tomato feeds – liquid feeds usually contain more nitrogen to promote green leaf growth, while tomato feeds have higher concentrations of potassium to produce fruit. That said, there’s enough potassium in a liquid feed to keep the pots of bedding plants blooming happily all summer.

Best liquid plant food

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Is Seaweed a Good Plant Food?

Many gardeners, especially those who use organic methods, swear by algae. In its natural form, it can be used to add organics to the soil. It also contains small amounts of phytonutrients, including traces of micronutrients that may be lacking in conventional feeds, as well as plant enzymes and plant hormones such as cytokinins, auxins and gibberellins. These are supposed to support the uptake of water, the growth of roots and the production of chlorophyll for photosynthesis.

Perhaps this is why there is confusion as to whether products containing seaweed extracts are feeds or stimulants. Some conventional feeds contain algae, but the two algae products we included in our trials, Maxicrop Original and Westland Liquid Seaweed, are both called stimulants. Neither give an NPK rating and manufacturers talk more about their ability to promote root growth to ensure plants can absorb nutrients. In our study, we found that using an algae stimulant had some benefit compared to the pots we didn’t feed, but the benefit was minimal.

For plants that require a high level of nutrients, such as B. Pelargonium, it is best to use a conventional food, which you can supplement with an algae stimulant if necessary.

How we test liquid feed

In May we planted Pelargonium ‘Horizon Red’ in 10 liter pots filled with a Best Buy peat-free compost for patio pots. Each pot contained three plants and we grew three pots of plants for each product.

We decided to test the feeds with pelargoniums because they are very hungry plants that need a lot of fertilizer to grow well. They also clearly show nutrient deficiencies in their leaves, and there is marked variation in size and flowering depending on whether or not they are getting enough goodness.

The lack of the three main nutrients – nitrogen, phosphorus, and potassium (NPK) – can be diagnosed by changes in leaf color, as can a lack of most minor and trace elements. Nitrogen deficiency shows up as a yellow coloration or as a red or pink sheen on the leaf margins. Insufficient amounts of phosphorus and potassium can be seen in darker green leaves, which then develop pink or purple spots, or turn brown all over.

The feeds we tested came in a variety of forms – most were concentrated liquids, but two were soluble granules. Miracle-Gro Liquafeed Concentrated Universal Liquid Plant Feed came in a bottle attached to its own spray head. The concentrate was automatically mixed into the water jet coming out of the hose. Ecofective Organic Pour and Feed was a ready-to-use product that did not need to be mixed before use.

We have created a schedule for when the feeds should be applied. For each product, we have carefully followed the instructions for dosage and frequency of use. If the instructions suggested a frequency range – for example, every seven to 10 days – we chose the lower number.

We started using the products after the pelargoniums had been in their 10 liter pots for four weeks, at which point the forage in the peat-free compost they were growing in had been used up. We continued to feed and evaluate our plants until the beginning of October.

We rated the size of the plants, how well they flowered, and their leaf color every two weeks, and recorded that each dead head was moved. At the end of the trial in early October, we cut the plants at the base and weighed each one to get an accurate size measurement.

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