If you’ve never started seeds indoors it might feel a little daunting but with the following 8 Pro Tips you will be well on your way to getting a jump start on this year’s garden. Not only does starting seeds indoors extend your growing season but with today’s seed catalogs it opens up an exciting world of varieties to choose from that you won’t find at a big box store. It also is more cost effective than buying starts, puts you in control of what your plants are fed, and generally results in higher yields.
Whether you’ve struggled with seed starting in the past or are just venturing out the following tips will help guide you through the process. Don’t worry. It’s likely that you will have some seeds that won’t sprout or you may have a seedling or two that may look funky. This is perfectly normal. But the cool thing is that you will be well on your way toward an earlier and more bountiful harvest!
Pro Tip #1: Know Before You Grow
Before you go hog wild with seed ordering it is helpful to gather a little information ahead of time.
- Check the USDA Plant Hardiness Zone Map to make sure the plants you are considering will thrive in your region (other countries can still use the temperature ranges). I like to even purchase my seeds from growers who are from a similar zone or colder to make sure those plants are acclimated to your area.
- Check to see when the last frost is in your area using The Farmers Almanac. That date is a calculated guess however nature can always pull a fast one on us so just be aware of your conditions. Once you know the last frost you can begin to count backwards when to start warm season (needing higher soil temperatures) vegetables like tomatoes, peppers, eggplant, squash, cucumbers, etc. The general rule of thumb is 6-8 weeks before the last frost but certain veggies like peppers, onions, and celery can require even longer. When it comes to cool season crops like broccoli, cauliflower, cabbage & brussel sprouts you can start them indoors during the summer where it “hopefully” is cooler than outside getting them ready for a fall crop. It’s the same process counting backwards from the anticipated 1st frost of the season in autumn.
- As you select seeds, be mindful of “maturity dates.” How many days until the vegetable is producing a crop. If you live in zones that have a shorter growing season you might want to select shorter maturity dates.
Pro Tip #2: Choose Your Seed Starting Container
Just about anything can be used to start seeds as long as it is at least 2” deep and has holes for drainage & air. Start with relatively clean containers. If you want to get sentimental about it this is the cradle that your babies will be born in! Use popsicle sticks or strips cut from old plastic containers to mark with a permanent marker what you are growing.
- If you will be starting a lot of seeds, then plastic trays like the one pictured above will make it a lot easier.
- Shoe box lined with aluminum foil – Has the added advantage of reflective heat. Check out this great article.
- Peat pots/Coir pellets – They are biodegradable but often don’t break down fast enough.
- Newspaper pots – This is a fantastic way to repurpose paper and feed your garden. Here’s a super article to get you started.
- Plastic dishpans – With drainage holes drilled into it.
- Egg cartons – Again with drainage holes in each cell.
- The list can be as long as your imagination!
Pro Tip #3: Not Just Any Soil Will Do
You can bypass this tip, dig some soil out of your garden, and throw it in a container but you won’t be happy with the results. My first choice is organic “seed starting mix”, but potting soil can work as second place alternative. Why seed starting mix? It is less dense for young roots to get established, provides extra room for oxygen, and drains well helping to prevent “damping off” disease.
True, seed starting mix is a little pricey. So if you want to flex your frugal muscles you can make your own using equal parts of vermiculite, peat moss, and perlite for a fraction of the cost.
Pro Tip #4: Planting Considerations
- Make a schedule when to plant each seed using my free handy “Seed Starting & Planting Guide”
- Seed companies get busy toward spring and their quantities are limited so order early.
- Use fresh seeds for best results. But didn’t archaeologists plant wheat seeds found in an ancient Egyptian mummy sarcophagus and they sprouted? Maybe, but most seeds have a shelf life of 1-3 years.
- Not all warm season veggies need/should be started indoors. As a rule root crops like carrots & beets don’t fare well in pots. Also, beans, corn, and some say peas, squash, & brussel sprouts although I have had success sowing them indoors.
- Some seeds are on the diva list and require special treatment. Seeds with tough outer shells may benefit from soaking overnight. Other seeds may require even more pampering but your seed packet should specify.
- Gently water the soil in your containers until water comes out the drain hole. The depth to plant seeds is on the seed packet but the general rule of thumb is to plant the seed twice as deep as their size.
- Plant 2-3 seeds per growing cell as you can always thin them out if they all germinate.
Papa Dan-ism: “Some seeds are on the diva list and require special treatment.“
Pro Tip #5: Moist But Not Too Moist Is The Sweet Spot
Seeds are tough but once they start to germinate they are as needy as a newborn baby. They need a constant source of moisture but too much water invites rot and damping off disease and too little hits the brakes on the germination process. Get used to sticking your finger into soil to get a feel for what is actually going on. The moisture in the soil needs to be monitored daily.
As seeds are germinating they also respond well to humid conditions. This can be achieved with clear domes over your growing cells, repurposing clear produce containers with lids or clear plastic wrap loosely over the top with short popsicle sticks to hold it up so it doesn’t adhere to your plants. As your seedlings emerge gradually remove the cover so they can adjust to life without high humidity. To keep your soil moist many like to use spray bottles so as not to hurt tender seedlings or I love this little doodad that goes on the end of a 2 Liter bottle.
Pro Tip #6: Bright And Cozy
As I said earlier, germinating seeds are big babies. They like to be warm and cozy away from cold drafts. Some DYI options are putting your trays on top of an older refrigerator or on top of a DVR or other electronic device that emits heat with some spacers between the two. But the absolute best route to take is a heat mat with an adjustable thermostat. In my experience, heat mats speed up and almost double the number of seeds that germinate.
Once the seedlings emerge they will be hungry for light. Slowly remove any humidity features you have in place. The picture above shows that it is possible to grow warm season plants in a south facing window on the cheap (no heat mat or grow lights). The only downside is that your seedlings will be a little leggy, possibly stressed, and your germination rates will be lower.
A much better option is to place them under grow lights. These can be LED or even an old shop light will work. Lights that are at least 5,000 Lumens or higher with a “Daylight” Kelvin rating work best. Try and keep the lighting 2-3” above the plants between 12 & 14 hours a day. You just can’t get that much quality light during the winter even in a south facing window. Following these tips, if you listen really hard, you may hear your baby seedlings cooing contentedly!
Papa Dan-ism: “Following these tips, if you listen really hard, you may hear your baby seedlings cooing contentedly!”
Pro Tip#7: Stinky Good Stuff
After the seedlings develop their first true leaves start feeding them about once a week with organic, diluted, balanced, water soluble fertilizer. Everyone of those words is important. Follow the directions on the label but then calculate how to make it half strength. Be sure you apply the fertilizer to the soil while avoiding the leaves so they don’t get “burned.” Why do they need any fertilizer at all? Because seed starting mix has very few nutrients and once the seedling uses up the stored energy in the seed husk it will be hungry. I know how some of us think. More is better, right? Not so fast. Over-fertilizing can lead to a host of unwanted problems.
Pro Tip #8: Moving On To Bigger Things
Once your seedlings exhibit several layers of leaves it is probably time to repot them. If they aren’t potted into a larger pot they tend to become root bound and their growth will be stunted. As you can see in the picture above you don’t have to spend a bunch of money on new pots. (I scavenged these red cups from local picnics.) Fill them with organic (OMRI Certified) potting soil and compost. (Another pro tip is that if you are buying soil/compost you can often get them 50% off at big box stores if the bag is broken)
Your seedlings are delicate so transfer with care. If you have several plants in one space you can tease them apart to plant individually or snip off the weaker ones for one strong start. Try and make the planting hole deep enough for the roots to extend, cover with soil and water well. Moist but not too moist. Tomato plants are unique in that you can plant them all the way up to their first true leaves and new roots will form along the stem making a healthy root ball. You can even go hard core and later transplant them a second time into even larger pots.
As it gets close to the time to plant your starts outside it is time for some tough love. They’ve lived a sheltered life up to this point. You will need to put them outside when temperatures are warm enough, out of direct sunlight, for just a few hours to begin with. Bring them in at night. Continue this process gradually exposing them to longer periods of time, more direct sunlight and temperature extremes. After at least a week they are ready to leave the nest and be planted. There you have it. Eight pro tips from seed catalog to harvest. You’ve got this!
