Indoor seed growing is always a joy for many reasons, not the least is that it means winter is nearing an end and spring is not far off. Of course there are many lessons learned each year as we try new seeds and new techniques that often do not yield the results we hoped for. Personally speaking, despite any setbacks…soggy seedlings and all, I still find it so inspiring that so much life, joy, beauty, food and medicinal elements come from such small seed.
There are a few basics that can help the novice who wants to start indoor seed growing and of course there are countless articles in magazine, books and on-line. Please take the following information as a starting point…off you go now, as there are countless seeds to plant.
Before choosing seeds, remember that the soil and lighting conditions of your garden need to be considered, just as you would when purchasing live plants. The light requirement of the plants after germination is generally shown by a symbol on the seed packages of a sun for full sun through to a cloud for full shade.
Seed sources are everywhere from floral departments of large grocery stores, garden centres, hardware stores and even big box department stores. Of course dreaming our way through local seed catalogues is marvelous fun and gives the widest variety of choices for annuals, vegetables and even perennial seeds. In addition, the great photographs, detailed planting and maturity information as well as many new hybrids not available in stores, makes these companies a great source!
If you belong to a horticultural society or garden club, you are probably able to participate in a seed exchange for a good source of vial seed as well as information on the plants themselves. For those on their own, perhaps others in your neighbourhood have seeds to share or swap. Remember, once you have a hearty plant you love, whether grown from seed or purchased full grown, you will have all the seeds you need for next year’s growing season.
Annuals and vegetables are generally the easiest to start indoors as their germination requirements are quite straight forward. Perennials on the other hand may need stratification or scarification before germination can begin. Stratification is a cold period required to break the seeds dormancy, which can be achieved by a few weeks in the refrigerator before planting, or by planting directly in to the garden bed near the last frost date. Scarification is nicking or sanding through the seeds tough outer coat so the moisture required for germination can get in.
Seed packs will contain a great deal of information on the plant itself, including the light requirement as mentioned, and length of time for flowers to bloom or vegetables to harvest. With new varieties of both available, even maturity times have changed so reading the packages is always important.
Further information on planting depth, times, light requirements, and growing temperatures are provided to ensure you have optimal germination. In addition, specific details for more challenging seeds would also be listed. An example of this would be for seeds requiring light to germinate so you not cover them with soil, while others might need soaking, scarifying or stratifying. Plants that do not transplant well will also be indicated and these seeds should only be planted outside once the danger of frost is past.
Word of warning: If you plant too early, the seedlings and young plants may become spindly and overgrown, despite good sunlight or strong grow lights!
While regular potting soil can be used but as it can be heavy when wet, soilless mix is recommended. Jiffy pellets, which are peat moss compressed for ease of storage and use are readily available both in kits and often priced per piece. The advantage of these media is their inexpensive prices and that no containers are needed as the mesh around them ensures they retain their shape even in the wet, expanded state.
Jiffy pellet kits are readily available in most types of stores selling seeds as they hope to encourage customers to try their hand at indoor seed growing. There are many brands of soilless mix available at garden centre and many easy recipes for mixing your own.
As it has now been determined that peat Moss is not an infinitely available resource, grown coconut fibre or compost can be used instead with the addition of compost.
Basic Soilless Potting Mixes
- 4-6 parts Sphagnum Peat Moss
- 1 part Perlite
- 1 part Vermiculite
- 4 parts coconut coir
- 2 parts compost
- 1 part Vermiculite
- 1 part perlite
Coir is a natural fibrous material extracted from coconut husks, which are the byproducts of other industries that use coconuts for food products. In addition to many commercial items manufactured from these harvested husks, they are also used in horticulture.Frequently labelled as Coco Peat , this product is commonly available in gerden cnter as are vermiculite and perlite.
Coco peat is recommended as a substitute for shagnum moss (peat moss), because it is free of bacteria and fungal spore, and produces good results without the environmental damage caused by peat mining.
Coco peat is usually shipped and sold in compressed forms of bales, briquettes or discs which expand up to more than ten times their weight after the consummers add water.Unfortunaley while it is a great produce to hold moisture, it is low in nutrients and can compute for nitrogen in the soil, so when used as a soil additive compost or other slow release fertilizer should be added.
Containers and accessories
There are a wide variety of containers you can use for indoor seed growing, from small flower pots to any container with drainage holes (cell pack, pots, jiffy pellets, Styrofoam coffee cups, food trays etc.). Remember if reusing containers, to wash with them soap, water and a little bleach first and then rinse them very well to ensure any fungus, bugs or bleach is long gone!
In addition you would need trays to hold those containers, plastic covers or domes to keep the moisture in and labels to ensure plants are properly identified. Of course you can use the clear lids of takeout containers or even clear plastic veggie bags held above the seeds. I have found popsicle sticks wedged down in the corners of a small container works fine and I remove it once the seeds have poked out of the growing media.
Theses sticks can also be used as labels there or if broken off and placed in front of where you will place a specific seed. One drawback to these is that ink can run on the wood. You can buy plastic plant labels or even cut up margarine lids. There are many ways money can be saved and items reused and indoor seed planting is no different.
Fill the containers with your sterile planting media and moisten the mixture so it feels like a damp sponge about an hour an hour before sowing to let the water penetrate evenly. While wait you can collect all seeds and planting devices as well as go over the seed planting information to ensure you have soaked, scarified or stratified the appropriate seeds.
The most difficult thing about planting seed is getting the right depth especially for the smaller seed. In addition, the smaller seeds almost seem to disappear so for those a planting aid helps. There are small plastic seed holders available that have a tiny opening designed to let small seeds out one or two at a time. For the handy minded person, a small envelope can be sealed and then a tiny hole poked in the end, allowing seeds out.
Your newly planted seeds need to be watered lightly from the bottom of the pot or by using a spray bottle to ensure the seeds are moistened but not disturbed. When they are moist, cover them with a plastic dome and place them in a warm location to germinate. Other options for speedier germination are placing them on top of the fridge, under grow lights , safely by a warm heat source as they germinate best between 18 – 24°C. In fact, there are temperature controlled heating pads specifically designed for this purpose which are available in kits or individually at most garden centres.
Once germination has take place, make certain the dome or clear plastic cover is unsealed to ensure good ventilation and prevent fungal growth in the soil. Fungal buildup, called damping off can cause seedlings to turn black at soil level and die overnight. In the past I have had this issue when crowding pots and pellets too close together which also blocks good airflow.
Prevention is best, but antifungal products are available, and seedlings could be sprayed with commercial fungicides Mycostop or Captan , but there are healthier herbal remedies you can use. A home remedy that apparently prevents this as well is a one dusting of ground cinnamon on the soil surface. A Chamomile tea infusion of 3 tea bags soaked for about 20 minutes can be lightly misted over the seedlings. Garlic as well is known to be a natural fungicide, so mash up several cloves and boil then in about an inch of water and water in to the seedlings once cool. Of course good spacing and even a fan can ensure better air movement, no matter where you have the seeds growing.
Once the seedlings get an inch or two high, you can remove domes or covers completely, but keep an eye they not get too dry either. Water lightly still, once the soil begins to look dry.
Seedlings love light, so if you only have a few, placing them on a sunny window ledge should do the trick. For many of use with limited light and a seedling urge that is hard to control, grow lights are a good option. There are light stands, small lamps and many fixtures where grow light bulbs can be used instead of regular fluorescent tubes. Again, a much needed field trip to a garden center is a must, at least to research your options!
Grow lights or cool fluorescent lights work best and now there are a few frequency options such as natural, wide range and those designed to simulate sunlight. Ideally optimal amount of light for your seedlings under lights are 16 hours on, 8 off. And the lights should only be 4-6 inches above them to start. Remember, whether your newly sprouted plants are under lights or in a sunny spot, leggy seedling are an indication that the light is inadequate.
Transplanting & Fertilizing:
After the seedlings have formed their second set of leaves they can be gently transplanted in to individual pots. In addition, feeding them a general balanced water soluble fertilizer of 20-20-20 at approximately ¼ strength once a week, is recommended for good growth. Gradually increase the strength over the next few weeks as you prepare to harden the new plants and move them outside.
Hardening Off :
Before you move the young plants in to their final containers, or in to the ground of your garden, they need to adjust to the outside conditions they will call home. This process, which is called our seedlings into containers or the ground outdoors, it is essentially to “hardening off” is a gradual period of acclimatizing which ensures a good survival and growth of the once tiny seedlings.
As the light intensity, temperature outdoors, wind etc. is much different than what they were used to inside, begin by moving the trays and containers out in to a shady, protected area for a couple of days . Then gradually extending the stay and moving them over a week to ten day period, to where they get their ideal light, soil and temperatures needs.