Seed Starting 101

Avid and anxious gardeners eagerly await melting snow, so much that in the middle of December (or January), they start ordering seeds, especially now that hardy nursery plants have become harder to find in our post-Covid world. Unique seeds sell out quickly from places like Baker Creek Heirloom Seed Company, which specializes in such rare seeds as the Biquinho Yellow Hot Pepper, the Pork Chop Tomato, and the Taiwan Yard-long Bean. The temptations in online seed catalogs never cease. Avid and would-be gardeners alike can make their best use of off-season time to discover their own favorite seed companies and plan for the next growing season.

Placing Your Order - Want to become a committed gardener? Try perusing seed catalogs like Johnny’s Seeds, Burpee, and Seed Savers Exchange. Once you've explored your options, you'll have to consider what plants will grow best in your climate and area. No matter how often I'd like to order a Hara Madhu Melon, I'll likely never see it bear fruit without a regularly heated greenhouse. Likewise, know the date of the first and lasts frosts in your area (your growing season), and order seeds accordingly. Some great and easy seeds to start with include bush beans, peas, squash, lettuce, spinach, and zucchini. Some of these you'll sow directly in your garden (beans, peas, lettuce, spinach), and others you'll want to start indoors because they take longer to grow and are not as cold-resistant.

If you do plan to start some seeds indoors, don't forget to order seed trays with plugs or seed containers and soil. If you're really ambitious, you may also want to splurge on some heat mats and grow lights.

Organizing Your Haul - When your seeds start to arrive in the mail--and as your supply of seeds starts to grow--you'll want a way of organizing them, starting the seedlings, and planning your new spring garden. There are several tools I use to plan, store, and keep track of growing dos and don'ts:

1. Photo Boxes - After housing seeds in various containers, from padded envelopes to plastic buckets and cardboard boxes, I've landed on simple plastic photo containers to organize my physical seeds. Various photo storage options can be found for purchase online. Each of my plastic photo boxes contains seed packets of a certain vegetable, fruit, or flower (e.g. eggplant or lupin). I label each box and they fit within a larger, clear plastic storage container, equipped with utilitarian handle for carrying. This storage method gives me a simple overview of my seed supply, helps me find specific seeds quickly, and enables me to transport them easily.

2. Garden Journals - Keeping a journal of your garden plan, preparations, activities, and outcomes year by year gives you a record of where you've succeeded and where improvements can be made. Garden journals can be as simple or as detailed as fit your needs. A simple lined notebook can be divided into columns where you can keep track of the varieties of seeds you plant, when you first purchased them, where you planted them, and the conditions that helped plants thrive. Bookstores offer other, more detailed options specific to gardening, with pages to map out your current and future gardening space and places to document any disease, pests or other blight affecting your plants. Such notes are a valuable reference in future years.

Sample gardening journal

Sample gardening journal

Sample gardening journal

Sample gardening journal

Sample gardening journal

3. Trello Board - I use a Trello Board to keep track of what I need to plant when, as well as my annual list of gardening tasks (www.trello.com). Each card on a Trello board can represent a different task, with checklists, pictures, descriptions, and due dates within the card. Cards (or tasks) are moved from one column to the next as they work their way through the process. For instance, the columns in my Trello board include: Seeds to Purchase, Seeds to Plant, Seedlings Started, To Plant in Garden, Planted - 2022, To Fertilize, Planted 2021, etc. My own gardening Trello board looks like this:

Starting Seeds Indoors -

Once you have your calendar in place and your supplies have arrived, you’re ready to start planting!

You don't want to plant all your seeds at once. Make sure you read instructions for how soon before the last frost date you want to plant each type of seed. Also note whether the seeds are best started indoors or planted directly in the garden. Seeds like peas, carrots, beans, and onion starts you'll plant directly in your garden beds. If you're planting seeds that have a low frost tolerance or longer growing time to harvest, you'll likely want to start them indoors. Use your Trello board or other calendar to help you map out what seeds need to be started when.

When you're ready to plant a certain type of seed, prepare your seed trays, and have some way of labeling what you plant. After experimenting with all types of soil containers and planting methods, I've found I prefer seed plugs (small, compressed pellets of peat moss, usually 36-42 mm, that expand when you add water to the growing medium). Plugs keep the soil together and make the plant easier to transplant later down the road. I learned the hard way, however, that you have to peal off the outer plug fabric when you're ready to transplant. Otherwise it will stifle the growth of the plant.

If you choose to use seed plugs, make sure you have added enough water to the pellets to make them ready for planting. When my plugs are ready, I use a chopstick to make holes in the growing medium and drop in my seeds. As you plant your seeds, make sure you have some way of keeping track of what you planted where. Otherwise, it may be difficult to identify the plants later. You can use something as simple as popsicle sticks for a marker or make a map of your tray on a separate paper.

Once you've seeded a tray, make sure the plugs are not dry. As long as the plugs are moist, you should be able to put on the clear, domed lid that comes with most seed starting kits, and let the seeds do their magic. When the seeds have sprouted, you can remove the dome. Make sure to give the tray of seeded plugs even moisture over the next week or two; let the plugs dry out slightly before watering again thoroughly. Once the seeds have sprouted, they will grow the strongest in cool air and ample light. Make sure they have plenty of overhead light to avoid leggy plants. If some of my seeds don't sprout, I re-seed in those plugs.

Transplanting - When are your seedling plugs ready to transplant? If you've sown your seeds in larger containers, you may not need to transplant them until you move them into the garden. When I start my seeds in plugs, I typically transplant them once before moving them to the garden. Look for your seedlings to develop "true leaves" (four instead of two). At this point, you can transplant the seedlings from your plugs into larger containers and position them under grow lights. My seedlings grow this way until they eventually look like the ones you might buy in 2-packs or 4-packs at your local nursery.

If you arrive at this stage with healthy-looking plants, pat yourself on the back and have a celebration. Your plants may even grow larger than what's available in the stores. After about 3-4 weeks of growing under the lights, you'll want to start fertilizing them and prepare to move them into the garden.

Moving Plants to the Garden - Harden off your plants before you plant them in your garden. What does this mean? Plants started indoors need to acclimatize to the outdoor environment; planting them directly into the garden may be too harsh, and all your hard work will have gone to waste in the blistering sun or cooler night air. I keep a mini-sized greenhouse--literally a series of shelves covered by a tough, plastic fabric--on my back porch to harden off plants before moving them into the garden. Once they've spent at least a few nights (or weeks) in the protected outdoor environment--and if the outdoor temperatures are warm enough for that particular plant--I move them into the garden.

From a bird's eye view, my planting season typically starts in March and April with indoor seedlings, then transfers to the garden once the soil is workable in April/May. Nearly everything remaining gets transplanted by May, although I may wait to plant squash and pumpkins until early June, when the temperatures start warming significantly. New garden transplants will need plenty of water at first and may still need to be covered by floating fabric or row covers if the temperature takes a dip at the beginning of the season.

Use the following chart to help you know when you can safely plant outside--and when you might need to cover outdoor vegetables to protect them from last season frosts, and happy gardening!