From Seed to Garden: Essential Tips for Starting Plants Indoors Successfully — Garden Unwind (2024)

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Starting plants from seeds is one of the most rewarding parts of gardening. But it can seem daunting if you’ve never done it before. This guide will walk you through the entire process from soil to transplanting. Let’s get growing!

What You’ll Need

Starting seeds indoors doesn’t require much investment. Here’s what you’ll need to get started:

1. Containers - Seed trays, pots, or recycled items like meat containers.

2. Seed starting mix - A soil-less blend for proper drainage and moisture.

3. Watering can with a fine rose nozzle - For gentle watering.

4. A sunny window or grow lights - Shop lights work fine.

5. Seed heating mat - To simulate ideal growing conditions.

6. Labels - Help keep track of what you planted.

Choosing Seeds

When selecting seeds, focus on varieties that benefit from an early start:

• Tomatoes, peppers, and eggplants - Need a long warm season, so they must be started early.

• Leafy greens like lettuce, spinach, kale - Can be grown in cool conditions, so these are worth giving a head start in order to have home grown salad sooner rather than later.

• Herbs like parsley, basil, oregano - Will produce a lot sooner with a head start.

When to Sow

Getting the timing right is important when it comes to seed starting.

If you start too early, you will have seedlings that have outgrown their containers before the weather is warm enough for them to be transplanted into the garden. This results in weaker seedlings due to the stress of confinement, lack of nutrition, and a need for actual sunlight.

Starting your seeds too late means a later harvest period, or worse. Crops that need a long growing season like peppers, may not have time to produce for you before your first frost in the fall.

Check seed packets for the recommended time to start indoors based on your region’s last spring frost date. You can also use Johnny’s seed starting calculator.

Seed Starting Mix

Regular potting mix can work fine for seedlings, as long as there are not big chunks of wood chips in it. If so, sift them out.

Alternatively you can buy a seed starting mix that is light and fluffy. Experiment with different brands to find one you like. It’s best to buy it locally to save on shipping costs. You can also mix your own:

DIY Seed Starting Mix

Creating your own seed starting mix is easy, affordable, and allows you to control the ingredients. Here is an easy recipe:

Ingredients:

• 2 parts compost or coconut coir - Provides moisture retention

• 1 part vermiculite - Lightens the mix and improves drainage

• 1 part perlite - Also helps aerate and drain well

• 1 tablespoon lime per gallon of mix - Balances pH

Instructions:

1. Combine compost/coir, vermiculite, perlite and lime in a large bucket or wheelbarrow

2. Mix thoroughly until hom*ogeneous and no dry pockets remain

3. Moisten the mix with warm water until damp but not saturated

4. Allow to sit for a few hours or overnight to fully hydrate before using

You can add optional extras like worm castings, biochar, mycorrhizae fungi, etc. to provide nutrients and boost soil health if desired. Just be sure any additives are completely organic.

The ideal DIY seed starting mix is loose, lightweight, and free-draining but able to retain some moisture. Make adjustments depending on materials you have available. With the right balance of ingredients, you'll give fragile seeds the nurturing medium they need to thrive!

Sowing Seeds

To plant seeds:

1. Fill containers with moistened seed starting mix, gently firming it down.

2. Evenly space seeds to avoid overcrowding.

3. Refer to the seed packet for planting depth. Very small seeds are simply pressed into the surface. Larger seeds may be buried 1/4 inch deep.

4. Cover seeds with a thin layer of mix if burying them.

5. Gently water the seeds in using a watering can with a fine rose nozzle, or a hose on the shower setting.

6. Cover trays with plastic domes or plastic wrap to retain moisture.

Caring for Seedlings

Seeds prefer warm soil for germinating, around 70°F. Consider placing them on a seed heating mat for best results.

Some seeds need light to germinate, some need darkness, others don’t really care either way. While most fall into the third category, it is always wise to check. If it does not say what the seeds prefer on the packet, do a quick google search and make a note.

Some seeds need light to germinate, some need darkness, others don’t really care either way.

For most seedlings, as soon as sprouts emerge, move to a sunny windowsill or place under grow lights. LED shop lights work well and don’t generate much heat. Keep lights about 6 inches above the seedlings.

Watering and Aerating Seedlings to Keep Them Happy

Water the seedlings carefully by misting or bottom-watering to avoid fungus issues. Let the soil dry out slightly between watering and maintain good air circulation.

Using a fan on seedlings is not required, but it can help to strengthen stems and preventing damping off, a fungal disease that causes the sudden collapse and death of young seedlings, often at the soil line, due to various soil borne pathogens.

Turning a fan on your seedlings for 30 minutes to an hour a day is sufficient.

Once seedlings have their first true leaves, you may want to begin fertilizing weekly with an organic diluted liquid fertilizer like this one.

Alternatively, you can rely on amendments you add to your seed starting mix from the beginning. This is why I like to add worm castings to the medium. It provides a food source, so in this case fertilizer is not necessary.

When they fill their containers, it’s time to transplant!

Hardening Off & Transplanting

Before transplanting outdoors, seedlings need a week or two to gradually acclimate to the harsher outdoor conditions, a process called hardening off.

The easiest way to do this is to use a cold frame. You don't need to have a walk in hoop house, although I highly recommend building one if you get the chance!

A simple clear plastic tote will do the trick.

1. Place your seedlings inside and drill holes in the lid for air flow.

2. Set the container outside somewhere sheltered it will not blow away.

3. During the day remove the lid So that your seedlings don't get too hot.

4. At night put the lid back on.

This will help your seedlings get accustomed to the outdoor temperatures without exposing them to wind right away. It also provides them with a greenhouse environment that takes the edge off the cold.

After a week or two of the tote, you can plant them out in your garden weather depending.

When transplanting, disturb roots as little as possible. For most seedlings, you should dig holes the same depth as the seedling’s root ball and backfill with worm castings to give them a boost. Some things like to be planted deeper, like tomatoes.

Troubleshooting Seed Starting Issues

Even experienced seed starters run into problems occasionally. Here are some common issues and how to prevent them:

Leggy or Spindly Seedlings

If seedlings are stretching and weak, it means they aren't getting enough light.

• Move seedlings right under grow lights, making sure plants are no more than 6 inches away.

• Reduce room temperature.

• Add a fan for airflow.

Mold or Fungus

Damping off fungus can wipe out seedlings.

• Allow the soil surface to dry out between watering.

• Improve air circulation with fans.

• Sprinkling cinnamon on soil can help suppress fungus.

Seeds Not Germinating

• Make sure seeds are planted at the right depth for their size.

• Keep soil evenly moist but not soggy.

• Consider using a seedling heat mat to warm soil to the proper temperature.

• Old seeds can have lower germination rates.

• Expose some seeds to light if they require it to trigger sprouting.

Catching problems early is key. Observe seedlings closely and make any needed adjustments to get sprouts off to a healthy start. With careful preparation and conditions, you can avoid many common seed starting pitfalls.

With the right care and conditions, you’ll have thriving vegetable and flower seedlings ready to beautify your garden. Happy seed starting!

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1. How to Start a Vegetable Garden in 5 Easy Steps

2. Container Gardening 101: Growing Plants in Small Spaces

3. Top 15 Beginner Gardening Mistakes to Avoid