Starting Seeds Indoors

Quite a few people have asked me about getting their seeds started indoors.  It is not as easy as getting them into soil and putting them in a window.  Yesterday, I started a flat of flowers so I could give you the step by step of my process.

First of all, use a good planting calendar to find out what to start inside, what to seed directly into the garden, and when to do it.  Look under “tools” at the right side of the blog and choose one of the planting calendars.  They all do the job.  I use a frost-free date of May 5th when I do my calculations.

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Once you have decided what you want to get started, you will need a tray or small pots (I like trays with clear plastic dome covers), soil (use potting or germinating mixes, not soil from outside), a water source, and LIGHT.   A heating mat is also really useful, but in lieu of that room temperature and a dome cover will get you by.  In my opinion, a “grow light” is a must have.  All of the times I started seeds and failed was because I thought the light at a window would do the trick.  Strong, healthy transplants need the broad spectrum of light that only comes from being directly outdoors or from a special grow light.  How much you spend, how many, and what type of grow light you get are dependent on your situation.  I have one very nice fixture (the one pictured) that cost me about $200 and does an AMAZING job.  I also have less expensive fluorescent fixtures that plug right into power strip that I purchased locally.  They do OK.  When my transplant cart gets really full (which will be this week), I will rotate flats into the best light.  I hope to buy another high-end fixture this year.  For you locals, you can shop grow lights at Bennets, Menards, and Rural King. Other places have them, I am sure, but this is where I have had good luck finding them.

I also have a 4 shelf mini greenhouse I bring indoors to keep all my seedlings on.  The advantages are: I can keep all my seedlings in one place, the plastic cover helps maintain heat and moisture, and it is easy to attach lights and heat mats to each level.  It is the best way minimize the space I need.  If you have a small garden, this is overkill, but if you are ever interested, here is one similar (a bit smaller) to the one I have (and it is a fantastic price): Mini Greenhouse.

In the photos, I am using Burpee growing pellets.  I do not like the Jiffy pellets which are widely available. This is not the cheapest way to go, but I find they germinate seeds better, are easy to store and use, and hold moisture fantastically.  In past years, Burpee trays with the pellets inside have been available at Home Depot and I highly recommend them.  I have all the trays I need now, so I buy just the pellets via mail order.  I add one pellet to each cell making sure they are sitting flat against the bottom (not sideways!) and I use my sprayer at the sink to add warm to even hot water to the trays.  The pellets will expand.  Give them time and add more water as needed.  You can really soak them.  When I’m done, I drain the excess water from the tray and use my finger to break the soil up a little.

Now, you are ready to seed.  I add 2-3 seeds per cell in case one does not germinate.  When I took my Master Gardener Training, one of the most useful things I learned there was about seed planting depth.  This is the rule of thumb that I use:  plant the seed about as deep as the width of the seed.  I most cases, that means quite shallowly!  Lettuce seeds for instance are tiny.  I don’t even cover them as much as make sure that they are pressed into the moist soil.  For slightly larger seeds, I just make sure they are covered.  For any seed you ever plant, always make sure that you press them in.  When I was teaching Lillian to garden as a toddler,  I explained to her that the seeds needed to be tucked in to bed in order to grow, so make sure they have good contact with the soil.  I also taught her you should sing them a lullaby, but that is not a must 🙂  The year we moved to the farm, Lily was 2, and she grew a pumpkin plant that she sang “Twinkle, Twinkle Little Star” to every evening.  She harvested 4 beautiful pumpkins that fall.  Just saying.

Make sure you LABEL your plants.  A plant marker and a Sharpie is NOT the way.  Trust me.  I have been down that road and ended up with tomato “grab bag” after all the “sharpie” names have washed away.  This year, I am using a special pen for tagging plants in nurseries. So far, so good.

After seeds are sown, labeled, and tucked in, get them on the heat pad (if you are using one), cover them with a dome (if you have one), and get them under some good light.  From then on, you really just need to maintain those outdoor-like conditions until it is safe to plant outside. Check moisture several times a day.  A dry seedling can die quickly, but do not flood them.  I water in 2 ways–with a spray bottle and with a turkey baster.  The turkey baster does a great job of getting water to the soil without pounding tiny seedlings.   The sprayer helps with humidity and also is the perfect way to water ungerminated seeds as well as very small seedlings.  Different seeds germinate at different rates, so don’t assume you did something wrong unless you are well outside the expected time period.  Most of my zinnia’s came up an inch overnight, while other seeds can take nearly a month.

I plug lights in when I wake and turn them off before I go to sleep.  I leave the heat mats on 24/7 for flats just getting started.  Once the seedlings are up a few inches, they will be fine off the mats if they are at room temperature.  Some seeds need greater warmth to germinate and then prefer cooler temps. This blog shows a nice chart:  Natural Gardening

The process of “hardening off” gets transplants ready for the move outside.  I’ll blog about that later on.