Growing Plants From Seed

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Whether it’s vegetables destined for the garden or a bonsai to-be, growing plants from seed is one of the most rewarding things you can do. In order to get a mature plant, you must ensure the new start is cared for throughout the younger stages of its life.

With that said, while growing plants from seed is very rewarding, being successful at it is not always so straightforward.

The plant kingdom has a vast and extremely varied host of different plants. Many plants produce seeds, some produce spores, and others produce pups, rhizomes, bulbs, or corms. Each type of reproductive strategy requires different triggering conditions to initiate the growth of a new plant. Not all seeds are the same however, seeds from different plants require different triggering conditions.

The Process of Growing Plants from Seed

In general, the process of a seed initializing the growth of a new plant follows a set path. While this does not hold true for every seed, generally the process is as follows. Once seeds are dispersed from the parent plant, a few conditions need to be met before germination occurs. Ideal germination conditions are created when the seed undergoes a few key processes.

While not all seeds need to undergo these processes, some seeds require only one or two, many seeds will not break dormancy and begin to germinate without them. The natural habitat range of the species often determines the needed processes. The germination processes most often needed are: hydration, stratification, and scarification.

Once the seeds germinate and that plants begin growth, there are a few things you can provide them to help them get the best start in life. Soil substrates, additives, and growth condition promoting tools are excellent additions to any growing setup. 

Next, we’ll cover some of the basic aspects and requirements of successfully growing plants from seed. While there are many ways to succeed at growing plants from seed, the methods and considerations that follow are what we’ve found to be quite effective.

Hydration

As the name implies, the process of hydration involves the seed being exposed to enough water that it permeates through the seed coat and reaches the embryo. Once water reaches the embryo, the process of growing can begin. As with most things, there are natural and artificial methods for hydrating plant seeds.

Seeds will naturally become hydrated as the seasons change and rainfall increases. Hydration is the simplest process to replicate by artificial means. Simply soaking seeds in a container of water for a period of time - usually 24 hours - will do the trick. In general, seeds should be hydrated before stratifying them, either cold or warm stratification.

It is worth noting that some resources and botanists consider the process of hydration as a form of scarification, this is not incorrect; however, we like to separate it as nearly no seed will germinate without water, whereas many seeds can germinate without scarification. The seeds of some species need both!

Stratification

The word stratification refers to the ordered layers within a system. For plant seeds, stratification concerns the seasons and the changes in temperature and precipitation that follow. Seed stratification is a natural process; however, there are ways people can artificially stratify seeds. Stratification is broken into two types, cold stratification (CS) and warm stratification (WS).

As you might have guessed, CS occurs naturally when seeds are exposed to the colder temperatures of winter. Leaving seeds outside in the cold winter months will suffice for natural CS. Artificial CS can be accomplished by putting the seeds in container or bag and leaving them in the refrigerator for the necessary duration.

Natural WS occurs the same way as natural CS except in the warm summer months. While WS can be done artificially, it not as simple as artificial CS. Placing seeds in a place where the temperatures can be kept high such as on a seedling heat mat will yield the best results. It is important to make sure the seeds do not dry out while undergoing WS.

Seeds requiring stratification tend to belong to species that live in areas where the winter months are drastically colder than summer months. Many species that live in either the northern or southern hemisphere are great examples. Plants along the equator are more likely to not need stratification to begin germinating.

Scarification

A plant's seed is, in essence, a nearly perfect vessel for growing a new plant. The seed acts both as a defense system and a nutrient storage facility for the new plant to-be. The seed coat helps reduce the intrusion of pathogens and inhospitable environmental conditions. Inside the seed coat, the embryo contains all the necessary nutrients the plant needs to start its life and get a bit of growth in before relying on its roots and leaves.

Due to the nature of a seed’s coat, some seeds need more unusual or extreme conditions for germination to begin. Scarification can take many forms but, in general, the action of scarification occurs either by physical or chemical means.

Physical scarification can be as simple as scratching the seed coat to the more extreme where a portion of the coat is removed. Any physical manipulation that damages the integrity of the seed coat will usually work. Some species require environmental scarification such as being burned shortly in fire. This method, while ingenious on natures’ part, is not the easiest to mimic artificially!

Chemical scarification most commonly occurs when seeds are exposed to strong acids. While it is possible to do this artificially, in nature this happens when a seed is eaten and not digested. The seed travels through an animals stomach and is exposed to acids where the coat is weakened. Once the seed is passed, the weakened coat allows water to intrude into the embryo.

Regardless of the mechanism, all of these scarification conditions act to weaken the seed coat and signal the embryo to begin growing.

Seed Starting Helpful Tools, Tips, and Tricks

When growing plants from seed, getting the seeds to germinate is only half the battle. There are many ways in which a successfully germinated seedling can be hurt or even killed. Environmental conditions (moisture, temperature, etc.) and pathogens (fungus, insects, etc.) are the two biggest culprits for plant loss. 

If you're growing plants indoors you’re likely to run into indoor plant “pests”. These are insects and arachnids that feed on your plants and damage them in the process. It’s important to manage indoor plant pests if your plants start to suffer.

Luckily, most of these problem areas can be managed and remedied so long as you pay adequate attention to your plants. These issues pertain to all plants not just seedlings; however, seedlings are more susceptible than mature plants to these issues. There are many growing products available today you can use to improve your success growing plants from seed. 

Moisture levels are tricky to maintain for some plants. This is further compounded by the fact that different plants need more or less water than others. If that wasn’t enough, how much water is retained by the soil substrate depends on its composition. Choosing the right soil substrate for your plant and checking for dryness is key to maintaining the right moisture conditions for optimal health! Using a humidity dome is a great idea to stabilize and maintain the moisture levels for your new plants.

In addition, knowing the best practices where watering your plant is concerned is vitally important. It may sound silly but many people get watering wrong. While it’s not intentional, there is a balance between watering amount and frequency and soil media. Knowing how to properly water your plants is key to having healthy plants.

Temperature is another important factor that helps seeds germinate. Many tropical plants need higher temperatures and high humidity. A seedling heat mat is an essential tool for ensuring the ideal temperature is maintained while your plants are just starting their growing journey. Many seedling heat mats today are adjustable and help to maintain temperatures ideal for root growth.

Seedling heat mats that include a thermostat controller are most ideal as they allow you to choose the temperature output. We’ve had great success with VIVOSUN seedling heat mats and always recommend them.

Lighting conditions are important throughout a plants life. Ensuring adequate light reaches your plants can literally mean the difference between life and death! Adequate light helps promote healthy seedling growth and gives the plants a good boost to their early life. The required light levels will depend on the individual plant species; however, most plants can deal with bright indirect light conditions. Giving your plants light can be accomplished either naturally or artificially.

Natural light for plants is best for a few reasons. Natural light follows the cycles of night and day much better than artificial light. Additionally, natural light includes the correct PAR (Photosynthetically Active Radiation) light wavelengths. Lastly, natural light is free! When giving your plants natural light from the sun, do keep in mind the heat given off can accelerate evaporation of water and dry soils out faster. Also, many plants cannot take the heat of direct sunlight, especially in the summer months.

Artificial light is another option, and it has many benefits! Artificial grow lights can be dimmable and have adjustable heights to accommodate various plant sizes and setups. In general, the heat given off by most grow lights is significantly less than the sun so soil dryness and heat stress are diminished but not entirely gone. Artificial lights can extend the amount of light your plants get as they can remain on when the sun sets!

Getting quality grow lights is always very important. LED plant grow lights are ideal for indoor plants as they run cooler than conventional lights, can emit full-spectrum light, have a long service life, and cost much less than conventional bulbs to run.

Seed Starting Soil and Other Substrates

Once the seeds have been hydrated and scarified - if needed - they are ready to be prepared either for direct planting or stratification. Seeds can be placed directly into a seed starting soil following the planting depth guidelines, if provided. Alternately, you can place the seeds on a damp paper towel, fold it loosely over the seeds, and place the paper towel in a plastic bag. Resealable bags work best for this, seal the bag about three quarters closed so the seeds still have access to air.

Once you have the seeds either in a small container with seed starting soil or in the paper towel-baggie setup, you can begin stratification, if needed. If the seeds do not need stratification, make sure to moisten the soil or paper towel and ensure the substrate does not dry out too much. Once the stratification period is over, remove either the container or the plastic bag from the refrigerator and place on a seed heating mat - if possible - and keep the soil moist until sprouts emerge.

When starting seeds in a paper towel, the seeds can be checked and, once they begin to germinate, they can be gently transferred to a container with soil.

In the wild, seeds are subject to grow wherever they land, because of this, most seeds will grow in most soils. Soils labelled 'Seed Starter' are not required to start seeds in; however, they do offer several benefits that your seeds will enjoy. These products are ideal simply because the composition is, generally, lighter in texture and water retention potential and is suited to help young roots become established.

In addition to providing your new seeds with an ideal soil media, there are several soil additives you can include to give your plants-to-be a head-start! Maintaining a plants’ ideal soil conditions is a key step to growing a happy, healthy plant. Two of the main additives that are most ideal to provide seeds are, mycorrhizae, a gentle plant fertilizer, and soil nutrient additives.

Soil Additives for Healthy Seed Starts

Mycorrhizae (my-co-rise-z-uh) are a type of beneficial fungus that form a symbiotic relationship (both organisms benefit) with plant roots. The fungus creates a thin filamentous structure called hyphae (high-fee), this structure is similar to a plants roots. The mycorrhizae connects to the roots of the plant and extends beyond the growing roots.

The fungus is capable of accessing soil nutrients and minerals the plant cannot access due to the limited reach of its roots. The nutrients are collected by the fungus and passed to the plant. In exchange, the plant provides the fungus with sugars it creates during photosynthesis. This relationship is not only one of the most interesting species interactions, it is also one of the most prolific.

It is widely established by scientists that the plant-mycorrhizae symbiosis is present for nearly every plant on earth. It would seem that at some point very far in life’s past, plants and fungi became intrinsically linked and remain connected to this very day. 

There are a lot of misconceptions with how mycorrhiza interact with plants, for an article dedicated to this topic, check out our detailed dive into the fungal world here.

Worm castings or earthworm castings are another beneficial soil additive for plants. This soil look-alike is actually produced by worms as they feed on compounds in soil. Also known as vermicast, this additive is high in humus (hue-miss) - the natural organic soil component. Additionally, worm castings help enrich the soil by increasing water and nutrient retention while also maintaining soil aeration. 

Water retention is important for healthy roots. Maintaining ideal soil conditions for plants is a delicate balance between water drainage and retention. Too little water leads to the plant drying out and either becoming stunted or dying altogether. Too much water can very easily lead to root rot which usually results in the plant dying unless drastic steps are taken to save it.

Nutrient retention refers to the soil’s ability to keep nutrients contained in the soil long enough for either the plant or the associated fungi to assimilate them for use. Nutrients in the soil, either naturally occurring or added through a fertilizer, can be washed out of the soil during watering. Worm castings act as a soil enricher due to their ability to retain soil nutrients.

Soil aeration is important as it ensures the soil around the plants roots is oxygenated and does not become waterlogged and lead to root rot. Soil aeration can be maintained in a number of ways, for more on soil aeration click here. There are various soil additives such as perlite, vermiculite, and coco chips that you can introduce to your plant’s soil that increase aeration and keep roots oxygenated and healthy.

At the Ethical Botanist, we recommend using worm castings over peat moss as a soil additive. While both additives have similar benefits, peat moss is a more environmentally harmful product to manufacture. Worm castings are a sustainable and, for all intents and purposes, renewable product. You can even make it at home with your own worm bin! This is only our recommendation however, if peat moss works for you and keeps your plants healthy feel free to use it!

Fertilizer is another common soil additive for new plants. While a seed contains all the necessary nutrients to help the plant begin its life, once it has produced its first set of true leaves, supplemental nutrients are needed. So long as the soil you’ve planted the seeds in has organic matter and is somewhat fresh, there will be nutrients present for the growing plant. With that said however, adding in additional nutrients with a quality fertilizer can help support your plants even further! 

Fertilizer is a must throughout the life of a plant if it is grown in a pot or a container. After the plant has spent time in the soil, the nutrients will eventually be taken up by the plant. This will lead to a deficit of soil nutrients and will inhibit the growth of your plant. With that said, plants require certain nutrients at certain times and too much can be detrimental to growth. For seeds in particular, choosing a very gentle fertilizer will yield the best results.

Growing Plants from Seed Wrap-up

To wrap up this discussion on growing plants from seed, we’ll review the main topics and the process that will generally yield the best results. Quality seed is important for viable germination. Hydration, scarification, and stratification are important first steps to increasing the likelihood of seed germination. Seed starting tools such as seedling heat mats and humidity domes help give your seeds the edge they need to sprout and begin growing. Soil quality and composition will encourage your new plants to continue to grow vigorously and help yield a beautiful, stunning plant.

We wish you all the best when starting your seed planting journey. The process of growing plants from seed is one of the most rewarding things you can do in life. It offers you first-hand exposure to botany and helps awaken an inner peace that is rare to find and, as we believe, only really reveals itself once you grow your own plants.