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Seed Starting 101
When is the right time for starting seeds in my garden?
Spring will be upon us before we know it, so now is the time to begin planning your spring garden. But when to start sowing seeds? The answer depends upon your zone.
Zones are determined by the United States Department of Agriculture. They separate parts of the United States into zones according to temperature. It’s important to know the proper times for starting plants from seed. This will enhance germination and help ensure healthy vigorous plants. I
Another important aspect of sowing seed that must be considered is using your average last frost date. You’ll discover that sowing seed based on your average last frost date is best because it’s based on your own garden’s climate. This date is identified as the first day of the year when there is less than a 50% chance a frost will occur.
If you don’t already know your average last frost date, the Old Farmer’s Almanac is a great resource for this information. Frost dates are calculated based on data from the NOAA National Centers for Environmental Information. It’s also helpful to know your average first frost date at the end of the season so you can determine the number of days in your growing season as well as plan your summer and fall sowings.
When in doubt, always check your seed packets for instructions, as they’re a valuable source of information for learning when to set out your seeds, what kind of soil they like, how deeply to sow them, and how long they take to germinate and grow.
Should I Start My Seeds Indoors or Outdoors?
Indoor Seed Starting
The Good: Indoor seed starting gives you the most control over your seedlings. You can easily track the germination rate of your seeds and give them more moisture or more warmth as needed. In a contained environment, seedlings are less prone to pests and diseases.
The Bad: Indoor seed starting requires a decent amount of space in a fairly warm room and, at the very least, a sunny window that’s preferably south facing. If all you have is a cold, dark basement, which necessitates the need for an indoor grow light system, you’re probably better off buying seedling plugs or starter plants, or waiting until you can sow your seeds outside.
How to Start Seeds Indoors
Make sure you clear some space in front of a sunny window that receives at least eight hours of light per day for your seed starting pots or seed trays. If this is not possible, then it would be advised to invest in a few grow lights that can simulate the sun for your seedlings.
Purchase your seeds from a trusted source.
Fresher, higher quality seeds will have a higher germination rate (meaning more will sprout) and will give you a head-start in growing delicious, nutritious vegetables. If you’re looking for non-gmo or heirloom seeds, then I highly recommend the Seed Savers Exchange. They are my favorite seed company whose mission is to conserve and promote America’s culturally diverse but endangered garden and food crop heritage for future generations by collecting, growing, and sharing heirloom seeds and plants.
- Seed starting mix or potting mix for seed starting
- Large container for mixing
- Small containers for seeding or seed trays
- Plastic plant tray, baking sheet, or other suitable “saucer” for drainage
- Plant markers
- Fine-mist spray bottle
- Pour your seed starting mix into the large container and wet it thoroughly. You want all the water to be absorbed and the mix to be moist before you start.
- Scoop the seed starting mix into each of your small containers, leaving about 1/2 inch at the top, and place the small containers in your plant tray.
- Sprinkle a few seeds over the seed starting mix (about three to four if they’re large, or a hefty pinch if they’re small). Repeat with the remaining containers and seeds. Don’t forget to label each container!
- Following the seed packet instructions, cover the seeds with the seed starting mix. As a general rule of thumb, seeds should be covered with a thin layer equal to their height, anywhere from 1/8 inch to 1/2 inch or more. Some seeds don’t need to be covered at all, as they need light in order to germinate, so simply press them into the seed starting mix.
- Tamp down gently on the seed starting mix with your fingers (or the back of a spoon) and thoroughly mist the surface with your spray bottle.
- Place the plant tray, with all of your newly seeded containers, in a sunny window in a warm location. Keep the seed starting mix evenly moist until you’re ready to transplant the seedlings into your garden. Use the spray bottle to avoid dislodging the seeds or damaging your seedlings as they grow.
Hardening Off Your Seedlings
Young, tender seedlings that were grown either indoors or in a greenhouse will need an adjustment period to acclimate to outdoor conditions prior to being planted in the garden. This transition period is called “hardening off.”
Hardening off seedlings gradually exposes the tender plants to the wind, sun, and rain. toughening them up by thickening the cuticle on the leaves so they lose less water when exposed to the elements. This helps prevent transplant shock, the term used for seedlings that languish, become stunted or die from sudden changes in temperature.
The length of time a seedling requires to harden off depends on the type of plants being grown and the temperature. Be flexible when hardening off your seedlings and prepare to whisk them indoors or cover them if there is a late freeze or snow.
Here’s My Approach to hardening off seedlings:
- About 7 to 10 days before your seedlings are ready to be transplanted, take them outside and leave them in the shade for a few hours in the morning or afternoon. Bring them inside before nightfall. Repeat for the next day or two. If the weather is exceptionally windy or cold, wait until it clears up before attempting to harden off your seedlings.
- After their two- to three-day introduction to the outside world, place the seedlings in dappled sunlight for a few hours in the morning or afternoon. Bring them inside before nightfall. Repeat for the next day or two.
- Next, leave them outside all day in direct sun and bring them inside before nightfall. Repeat the next day. If the weather is exceptionally hot, shelter your seedlings during the harshest part of the day or move them into the partial shade.
- Finally, let your seedlings live outside all day and all night until they move into the garden.
Seed Starting Your Garden Outdoors
Nature sows directly outdoors. It’s often the easiest for you, as well. Many times, plants sown directly outdoors are more vigorous and healthier than transplants. Direct-sow tap-rooted vegetables, such as carrots or radishes, that don’t transplant well as seedlings. Beets transplant well, but they prefer growing in cool soil so there’s no reason to start them indoors.
Heat-loving crops that need a long season to produce, such as tomato, pepper, or eggplant, don’t yield as strong a performance when they’re direct-sown, especially in regions with short growing seasons. Start these seeds indoors. Other heat-loving crops, such as pumpkin, squash, cucumber, beans, and melons, thrive when direct-sown after all danger of frost is past.
Your soil may be very different from the soil that’s in a neighboring yard. A soil test can help you determine what type of soil you have and provide suggestions for improving it. You will want to use a soil thermometer to determine the temperature of the soil before sowing, as optimal seed germination temperatures vary by variety. Contact your local university or Cooperative Extension Service. for information about soil testing, to see if your soil needs improvement to grow healthy, productive plants.
Prepare Soil – Use a rake or hand fork to loosen the soil. Break apart large soil clumps, and remove debris, such as sticks, rocks, and roots. Add amendments to the soil, such as fertilizer and organic matter, to create the most ideal growing situation. Finish by creating a level surface.
Dig In – Most seed packets describe planting depth. The rule of thumb is to plant at a depth equal to three times the seed diameter. There are exceptions. Some seeds require light to germinate and should rest on top of the soil. Press such seeds firmly against soil using a board or trowel to ensure that moisture cradles the seeds.
Follow these other seed-sowing tips:
- If your soil has a high clay content and tends to crust over as it dries, cover seeds with a commercial seed-starting mix.
- When sowing extremely small seeds, such as carrots or nicotiana, mix seeds with sand to aid in dispersal.
- When sowing larger seeds, including peas and beans, create a long furrow and dribble seeds at the proper spacing. Alternatively, use a bamboo stake, dibber or pencil to form individual planting holes.
After sowing seed, soil should be kept moist, but not soggy, making sure the top layer of soil where the seed is growing stays moist. Dip a finger in the soil below the seed depth to check for moisture. Depending on your garden’s climate, you may need to water more than once a day to keep the seed and soil moist. Too little moisture can prevent the seed from germinating, while too much water can contribute to seed rot.
Sunlight is essential for plant growth. Most flowers and vegetables need “full sun”, which means at least 6 hours of direct sun during the day. “Part shade” plants do best in 4 to 6 hours of unfiltered sun each day. A few types of plants will be happy in “shade”, which is less than 4 hours of sun or day-long filtered sun.
What types of plants should be started outdoors?
- Plants that don’t transplant well (weakened by root disturbance).
- Plants that require very warm temperatures to sprout and get established.
- Root crops (carrots, beets, parsnips, etc.)
Here are some examples of varieties that would benefit from outdoor sowing: Vines (like cucumber or pole beans), carrots, beets, corn, cilantro, and parsley, and fall harvested crops like any of the squashes.
By following these guidelines and keeping a journal, all that’s left to do is watch your seeds grow into beautiful, healthy plants!
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