The Ultimate Guide to Seed Starting (Bonus PDF) - Julia Dimakos (2024)

Have you started your seeds this year?

Do you start them indoors, or do you plant them directly in the garden?

Perhaps you buy your starter plants from a local nursery or a big box store?

There are many benefits to starting your own seeds, like being able to grow vegetable varieties that are unavailable in stores, growing organic seeds or planting varieties that are not sold as seedling starter plants.

Starting your own seeds gives you control over what goes in your garden. If something produces well, you may choose to save seeds from it and replant it again in the following year. This process of saving seeds from the best plants, then replanting them year after year, helps to breed plants that are adapted to your backyard microclimate. Over time, seed saving creates varieties that are strong enough to resist local plant viruses and pests. You probably won’t have the same resistance from store bought seedlings.

I recommend waiting to start your seeds, instead of starting them too early.Seedlings require 15 to 16 hours of direct light to grow successfully.The short days of winter won’t provide your little seedlings with enough daylight to grow into healthy plants.If you don’t have a grow light or supplemental lighting, wait to begin your seeds until the days are at least 12 hours long.

Seed starting is actually quite simple and fun! It does require a few tools.

Seed Starting Supplies:

• Soil-less Seed Starting Mix or Pro-Mix (not garden soil)
• Seed trays
• Clear plastic domes for trays or clear plastic wrap
• Seeds
• Labels
• Grow light system (see notes in yellow box)
• Automatic Timer
• Seedling Heat Mat to speed germination (Optional)
• Spray bottle or small watering can
• Vermiculite
• 4 inch pots

Here’s what you need to make your own Growlight System:

1. Shop lights, either a 2-light or 4-light grid, using “daylight” or “plant” light tubes, at least 1 or 2 units per shelf, depending on the size of the shelf.
2. Shelf (either a multi-tiered wire rack or wooden shelf) or table.
3. Chains and hooks to hang the lights and move them up and down as needed.
4. Hang your lights 2 inches above the top of your seedlings and adjust them upwards as they grow.

*Note: If you don’t have grow lights, don’t despair. Once the days are at least 12+ hours long, place your trays in your sunniest south-facing window. Then as the seedlings grow and stretch towards the light, turn your trays around so the seedlings face away from the window. Your seedlings will quickly grow back towards the light and straighten out.

General rule for seed planting depth:

Plant your seeds at a depth of 3 times the size of the seed.

11 Steps to Seed Starting Indoors

Directions:

1. Using my Seed Starting Calculator, create a schedule of what to plant first, according to your final frost date.
2. Pre-moisten the soil, either in its bag or in some sort of plastic bucket or dishpan. Stir the soil, until damp, but not soaking and break up any clumps that may form. Squeeze the soil, it should be wet enough to form a mould, but not dripping wet.
3. Fill your seed trays, 3/4 full with seed starting mix.
4. Following the seed packet instructions, add 1 to 3 seeds to the top of each cell in the tray. I always plant 2 to 3 seeds, depending on their size. The seed package will specify if the seeds require light for germination, or not. If light is required, gently push the seeds onto the soil surface for seed/soil contact. If light is not required, add a thin layer of soil and gently tamp down the top to eliminate any air pockets. For larger seeds, like corn, peas, squash or cucumber, push 1 seed into the soil, at the depth suggested on the seed packet.
5. Water the seeds with a gentle stream of water or use a spray bottle.
6. Cover the tray with a clear plastic dome. These are usually sold with the seed tray. If a dome is not available, lightly cover your seed tray with plastic wrap. I use popsicle sticks or toothpicks to keep the plastic from touching the soil surface.
   

   

   Onion seedlings, freshly trimmed

   Some plants, like peppers, require bottom heat for germination. In this case, you may use a heat mat under the tray. A heat mat is not necessary if you don’t have one, but it will take slightly longer for your seeds to germinate.
7. After the seeds have germinated, remove the clear dome or plastic wrap and place the tray under a grow light.
8. Adjust the lights to hang 2-inches above the tray and keep the lights on for at least 15-16 hours per day. I recommend using an automatic timer. This frees you up from having to wake up early to turn the lights on and be there in the evenings to turn them off.
9. As your seedlings grow, adjust the lights to hang no more than 2 inches above the plants.
10. Repot the seedlings into larger pots, such as 4 inch pots, after they have produced their first set of true leaves. Then place them back under the lights.
11. Harden off your seedlings for 2 weeks prior to planting them outside.
12. Transplant your seedlings into the garden after the last spring frost or based on the seed packet’s recommendations. See Outdoor Planting Calculator for specific planting dates for your hardiness zone.

To help you plan out your seed sowing calendar and keep track of your seedlings, I’ve created a Seed Starting Schedule to help you stay organized.

How to Use Your “Seed Starting Schedule”:

1. For each seed variety that you plan on starting, simply fill out a line in the chart, including the seed type and variety and the (recommended) number of weeks to start your seeds indoors, prior to transplanting out (this is written on the back of the seed packet).
2. Using my Seed Starting Schedule, enter the sowing date for seed variety on your list.
3. After sowing your seeds, fill in the date and the number of cells/pots planted. The number you plant is based on your own family’s needs and/or garden plan for that year.
4. When most seeds of one variety have germinated, fill in their germination date, including the final number of seedlings you are left with.
5. Using theOutdoor Planting Calculator, find the correct transplanting out date and add it to the schedule.
6. When your seedlings are transplanted out into the garden, add that date to the schedule, including the final number that were transplanted out.

This chart should help you stay organized. By keeping track of your seedlings, it will help to stay organized and plan ahead for next year’s garden.

I hope these 11 steps, along with the Seed Starting Schedule will help you with your seed starting plans and show you how simple and satisfying it truly is.

I would love to hear about your experience. What seeds are you planning to start first? Are you growing something new this year?

Please share your experience and questions in the comments section below.

Happy Gardening!

Here are the tools that I mentioned in the post.

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