Every year, gardeners look forward to this time when they can begin growing again. Flowers and vegetables with long growing seasons may need more good weather than Mother Nature provides in your region. You can get around this constraint by starting these varieties indoors early. By simulating springtime conditions indoors, you can trick your seeds into germinating and growing, despite the winter weather outside!
But watch out- it is possible to start seeds TOO early! Starting seeds too early can lead to seedlings outgrowing their pots and suffering from lack of nutrition, light, or space. They may also be at an increased risk for shock when they are finally transplanted outdoors. Familiarize yourself with your varieties and use our Planting Guide to help get the timing right: osc-vegetable-planting-guide
In this post, we’ll discuss how to set up an indoor grow station, with a focus on providing the right:
- Air circulation
Temperature (part 1: germination)
In order for germination to occur, seeds need to believe that conditions are suitable for growing. You can simulate temperate springtime weather by providing warm, even soil temperatures for the full germination period. To begin, line all-purpose planting trays with Jiffy strips or cell paks. Fill with growing medium and moisten with water. Sow seeds following the direction on the packet.
Next, provide a source of warmth to the base of your trays. A perfect warm place for germinating trays is on top of the fridge! Keep a few clear plastic domes on hand to cover trays of germinating seeds. This will create a greenhouse effect, locking in heat. If you’re out of room on top of the fridge or you are starting seeds that require very warm soil temperatures, you may want to invest in a few heated germination mats.
Keep germinating seeds away from windows and other areas that are prone to dramatic swings in temperature.
Temperature (part 2: growing on)
After seeds have germinated, the temperature should be lowered for “growing on.” Remove the clear plastic domes and heated germination mats. Move the trays from on top of the fridge to a grow stand or south-facing window. Growing on at a cooler temperature will help to prevent mold and moisture-related issues, and build up the hardiness of the plants.
Keep track of your varieties as you move them around by labeling them with garden markers.
Do you remember the old rhyme: “April showers bring May flowers”? Well, it’s true! Spring rains are another cue to seeds that conditions are favourable for growing. In your grow station, you will simulate “April showers” by keeping your seeds moist (but not soaked) during the entire germination period. This can be accomplished easily by keeping germinating trays covered with a clear plastic dome and using a spray mister to moisten the growing medium as needed.
After seeds germinate and seedlings begin to grow, remove the plastic domes and watch your trays closely. The growing medium should be moist but never soaked. Keep in mind that trays in windows with strong sun exposure may dry out more quickly on sunny days. Additionally, as seedlings grow larger, they will require heavier or more frequent watering.
As soon as seeds begin to sprout, move them into the light. A good source of light is essential for strong development. For best results, indoor grow stations must be situated either: in a bright south-facing window, under grow lights, or both.
Plants know that lengthening days mark the beginning of the growing season. If it is very early in the year, even south-facing windows may not provide enough light because the days are short and the winter sun is weak. Watch your seedlings carefully to make sure they aren’t getting “leggy.” Seedlings that do not get enough light will grow too quickly as they “reach” for more. Leggy plants will not have the strength to support their own weight as they mature. If your seedlings begin to look leggy, it may be necessary to invest in grow lights or select varieties that do not require as much sun.
As your seedlings begin to grow larger, make sure there is room for air circulation between plants. Otherwise, moisture may become trapped and cause mold or other moisture-related issues. Thin seedlings as directed by the packet, and transplant into larger pots as needed.
Consider placing a fan near your grow station and direct a light breeze over your plants for a few hours each day. This will ensure good air circulation, even if your shelves are getting a little full! It will also help to encourage strong stems and build hardiness.
When grown indoors, your seedlings are restricted to the nutrients you provide. They may require more than what is available in the growing medium and in that case, it will be necessary to supplement their nutrition with fertilizer. The specific nutritional requirements will depend on the varieties and growing medium you’re working with. Call up a green-thumbed friend or head to your local garden centre to talk about the nutritional needs of your seedlings. Be sure to know which growing medium you used so they can recommend the best fertilizer (if any) for your seedlings.
Watch out! An overabundance of nutrients can be just as bad as too little. Measure carefully and watch your plants closely. When in doubt, ask an expert. Our horticulture team is always happy to answer questions at firstname.lastname@example.org
That’s it! Indoor grow stations vary dramatically from home to home and we’ve seen some very creative setups! Show off your growing station on Facebook or Instagram and tag us (@OSCSeeds). We may even share it to inspire others!
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