Winter fertilization, yes or no?
Many will want to answer that, no, we don't fertilize during winter. Fertilization must be done during the plant's growth period and, in winter, our houseplants are not growing. It is better to wait until the days get longer in the spring to start fertilizing again.
This is not wrong.
But that's not entirely true either.
In fact, our houseplants are not in total dormancy during winter. It's true that they seem to slow down and when spring arrives, bam! they come out of their torpor and offer us many new shoots. As if they knew exactly when it was time to start growing again. As if they could feel the coming of brighter days, and that the increase and intensification of the light made them explode with happiness. This state of exuberance, when compared to the calm in which they are in the winter months, can lead one to say that they sleep from October to March...
But, during these months, the plants we keep near the windows and those to which we offer artificial lighting are not in total dormancy in our temperate homes. They have a metabolic activity that continues, even in winter. Their cells do not stop working, they slow down. They continue to produce glucose thanks to solar energy (or that of our lamps which imitate solar energy) and thus manufacture their food. Photosynthesis continues. But quite simply, the metabolic activity of plants is proportional to the amount of light they receive. The less light there is, the less photosynthesis there is. (Our article on artificial lighting is available here and it talks about photosynthesis).
One of the reasons we need to water our houseplants less during the cooler months is because of this change in rhythm. Since their metabolic activity is slowed down, plants consume less water. Come to think of it, we too are less thirsty when it's not so hot...
And in fact, fertilization follows the same logic. If the plant continues its metabolic activity slowly, if we see that it shows signs of growth, even if it is slow, we can fertilize it, but slowly.
To fully understand the nuance between fertilizing during the active growing season and fertilizing during the winter months, it is important to understand how fertilizers work, in general.
N P K, what is this?
On the fertilizer containers, there are 3 numbers, which correspond to the percentage of primary elements: nitrogen (N), phosphorus (P), potassium (K). Each element plays a different role and this diagram can help us remember them.
Nitrogen (N)
Nitrogen is the element that helps the growth of plants, the development of foliage and aerial parts of the plant. It also contributes to the color of the foliage. Indeed, nitrogen is a component of chlorophyll and, if this element is missing, the whole process of photosynthesis is affected. Nitrogen is also a source of food for soil micro-organisms.
A fertilizer rich in nitrogen is recommended for seedlings or indoor plants with green leaves. It is also interesting for conifers, lawns and leafy vegetables.
Phosphorus (P)
Phosphorus contributes to flower development and root system growth. Fertilizers designed for flowering and rooting are rich in phosphorus. Of course, by strengthening the root system, phosphorus contributes to the growth of the plant.
In the summer, when you want your annuals to bloom to the max, a phosphorus-rich fertilizer should be purchased. It can also be recommended to help the rooting of newly installed plants.
Potassium (K)
Potassium has a role to play in the overall resistance of plants to cold, drought, insects and disease. It is like a shield for the plant. It is also involved in the development and ripening of fruits.
Potassium-rich fertilizers are often recommended in the garden for vegetables, for example, and also in the fall to help our outdoor plants get through the winter.
Complete fertilizer / incomplete fertilizer
A complete fertilizer includes these three elements. They can be in equal doses or not. An incomplete fertilizer is composed of one or two elements. It is not necessarily less interesting, it all depends on the needs. You have to take into account that if you have a good soil, the elements are naturally present. Sometimes it is not necessary to have a fertilizer that provides all three elements. You can also alternate the sources of fertilizers, in order to vary the contribution that will be made to the plants.
Secondary elements and trace elements
In order to grow, plants do not only need the three primary elements nitrogen, phosphorus and potassium. They will draw calcium (C), magnesium (M) and sulfur (S) from the soil. They will also draw a variety of trace elements, required in smaller quantities, such as chlorine (Cl), iron (Fe), manganese (Mn), boron (B), zinc (Zn), copper (Cu), nickel (Ni) and molybdenum (Mo). These elements are naturally present in the soil. But sometimes, for our houseplants, they come to lack and they must be renewed.
Synthetic fertilizers / natural fertilizers
Synthetic (chemical) fertilizers are derived from chemically transformed substances and have NPK proportions mostly above 10 (e.g. 20-20-20, 15-30-15, 10-52-10). They are powerful and act very quickly on the plant, because they are directly absorbed by the roots. However, their effect does not last very long, which is why it is necessary to renew the contributions frequently. It is to be noted that they often have an influence on the PH of the soil, that is why it can be interesting to vary them. They do not promote the microbial life of the soil beneficial to plants. Studies show that they even have the opposite effect.
Natural fertilizers are based on elements such as algae, fish, bones, manure from various animals or insects, etc. They have proportions that are mostly below 10 (5-1-1, 2-4-6, 5-6-1). They have proportions that are mostly below 10 (5-1-1, 2-4-6, 5-6-1). They are not immediately assimilated by the plants, because they first feed the soil. They have to be decomposed by soil micro-organisms, before being available to feed the plants. Their effect is therefore less immediate, but much more durable. And these fertilizers have the advantage of providing the substrate with secondary elements and trace elements that plants need and that are not offered by most synthetic fertilizers. They contribute to a better quality soil, richer in organic matter.
Fertilizers to stimulate a plant that does not grow
Contrary to what we might think, this statement is false. You should not fertilize plants that do not show signs of growth. Their roots will not be able to assimilate the mineral salts. These will simply remain in the soil and in the long run, this will be harmful to the plants. It is better to fertilize a growing plant to compensate for its efforts.
Let's not forget that the plants we grow in our homes are in closed pots and in a substrate that does not contain active microorganisms (unless we provide them: Soil Activator) nor rain to wash away excess mineral salts and regulate all this, as in nature.
Earthalive's soil activator can be added to the substrate or to the watering system at any time, summer or winter. It will increase the biological activity in the soil. It does not contain any genetically modified organisms or synthetic chemicals, but microorganisms that, once released into the soil, will allow for better growth and ensure the health of the plant. Soil Activator improves the water holding capacity of the soil, helps plants manage transplant shock, increases nutrient uptake, enhances soil nitrogen levels, releases nutrients from organic matter, solubilizes phosphorus and improves micronutrient availability.
Which fertilizer should I choose for winter fertilization?
As mentioned above, in general, plants should be fertilized in spring and summer because they are less hungry and thirsty during the colder months, which have a shorter period of sunlight. In winter, most plants are not in a state of active growth, so they should be fertilized gently.
We understand now why a synthetic fertilizer, very powerful and quickly absorbed, is not appropriate for a plant whose metabolic activity is slowed down. It can even harm it, or rush it and the result will be long weak shoots, without tone, because the plant does not have what it needs at this time of the year to have a robust and dense growth.
Choosing a natural, gentle fertilizer, which will act on the soil before being assimilated by the plant, will promote a much more balanced development and may suit its winter rhythm. You can even reduce the dosage indicated on the label and give regular microdoses, which will have the effect of vitamins throughout the winter. The result will be a plant that will not have grown in a dazzling way during the winter, but that will have gained strength to burst with happiness in spring, and that will have a substrate rich in organic matter and thus able to offer all the elements it needs. This is all the more important during the active growth period.
Here are some options for winter fertilization
Natural photostimulant fertilizer Stimyla (0,1 - 0 ,2 - 1,0) based on seaweed extracts and natural bioactive compounds is applicable by foliar spraying or by watering. It offers: faster growth, greener foliage, abundant and longer flowering, accelerated development of seedlings, facilitates the cutting of plants (the manufacturer suggests soaking cuttings and seedlings), better quality of fruits and vegetables, increases the vigor of plants and their resistance to diseases.
Vit-Alg Fertilizer Fertilizer (0.3 - 0.1 - 0.2) is a ready-to-use seaweed solution. The container, equipped with a sprayer, is ideal for weekly foliar applications. This product is perfect for those who prefer not to do the mixing themselves. Made fromAscophyllum nosodum (black seaweed), this fertilizer, which can be used both indoors and outdoors, increases the speed of growth and the beauty of flowers, stems and foliage. It is approved for organic farming.
Fresh Seaweed Fertilizer Acadie's Fresh Algae Fertilizer (0.6 - 0 - 6) is a concentrate to be diluted according to the label recommendations. It can be used as a foliar spray or when watering. This fertilizer is also composed ofAscophyllum nosodum (black seaweed) and can be used both indoors and outdoors. It offers relatively the same benefits as Vit-Alg (increases the speed of growth and the beauty of flowers, stems and foliage), but is more economically advantageous. It contains 60% organic matter and is approved for organic farming.
Acadia Fish Hydrolysate (2 - 4 - 0,5) is a concentrate resulting from a process of cold hydrolysis of fish which allows to preserve a maximum of amino acids offering a high contribution in nutrients. It quickly corrects deficiencies, encourages the proliferation of bacteria beneficial to the ecosystem, stimulates roots and flowering, feeds the soil with its rich nutrients, increases the sugar content of fruits and vegetables. It contains 37.5% organic matter and is approved for organic farming.
This product is ideal for use in alternation with seaweed fertilizer, as together they provide nitrogen, phosphorus and potassium.
However, sensitive noses should be warned: when used indoors with the windows closed, the smell can be unpleasant.
Liquid seaweed Bionik's Liquid Seaweed (0.36 - 0 - 0.22) is a concentrate to be diluted obtained by a process of transformation (micronization and fermentation) of the dry seaweed into a liquid product. In addition to nitrogen and potassium, this product also contains 0.5% calcium and 0.3% magnesium. Bionik claims that growth will be twice as active, that its fertilizer acts as an anti-stress for plants (drought, heat, cold, transplanting) and that it promotes rooting. Can be used as a foliar spray and during watering. Approved for organic farming.
Super Fly insect droppings from Gaïa Green (2 - 1 - 1) is a dry fertilizer made from the droppings of black soldier fly larvae. Although new to organic producers, this digested material has played an important role in plant nutrition for millions of years. Super Fly insect droppings is rich in essential nutrients.
Super Fly Insect Droppings can be used in a variety of ways: mixed with water, applied as a foliar spray, or added directly to potting soil (either on the surface or mixed in before repotting). Mixed with watering water, it helps to fight the midges of the soil (sciarides) and fungal diseases. It is a fertilizer that contributes to plant health and immunity. The slow but easy release of nutrients provides a rich source of chitin, beneficial bacteria and fungi for the soil. It is approved for organic farming.
Nutrifrass by CricketNutris (2 - 3 - 3) is somewhat in the same category of fertilizer as Super Fly. It is a dry fertilizer that can be applied directly to the surface of the soil or mixed into the substrate. It can be used for indoor and outdoor plants as well as for lawns. Nutrifrass is made of locust droppings, a biological raw material rich in essential nutrients, insect biomarkers, chitin, beneficial microbes and beneficial fungi. This fertilizer promotes plant resistance to disease by encouraging plants to generate high immune responses.
Fertilizer for seedlings, herbs and houseplants of Bionik (available in 85 g format : 5 - 2 - 6 and in 400 g format : 6 - 1 - 5 ) is a non-water soluble fertilizer that is mixed into the soil. It is mainly made of snow crab meal, seaweed, alfalfa and feather meal. Interestingly, it contains 4% calcium (which is quite high) and 0.9% magnesium. It is a complete fertilizer, containing all the essential elements for growth, and perfectly balanced for optimal and abundant foliage growth. Bionik claims that plants will produce twice as much foliage with a single application of this fertilizer. Approved for organic farming.
NuMix Citrus and Fruit Fertilizer (6 - 2 - 6) is granular. It can be applied to the surface of the substrate or incorporated into it. It is a fertilizer enriched with potassium, magnesium and calcium, which improves the sugar concentration of the fruit, making it tastier. It is specially developed for lemon trees, limes, orange trees, etc. It is approved for organic agriculture.
All these fertilizers are gentle enough to be used in winter. They have the advantage of being natural and contribute to the health of your plants as well as to the quality of the substrate from which they draw life.
Just goes to show that we can continue to pamper our plants in any season!