Starting Seeds for Your Flower Garden: Biggest Mistakes to Avoid
Updated February 12, 2024
Starting your own flowers from seed can be wildly fun and rewarding. Nothing will make you more proud, as a gardener, than watching your plant babies grow from a tiny seed to transplant to full-grown flowering harvest. Everyone that has a garden should try seed starting on a small scale!
Indoor seed starting can also be challenging and frustrating if you’ve never done it before. I grow thousands of my own cut flower transplants every year and I’ve run the gamut on seed starting mistakes. I’d like to share the wisdom I’ve gleaned from my failures here, to keep a record for myself and also to encourage you to start off with the right information!
Related: The Ultimate Herb Garden for Zone 6
The information below is applicable to flower farming, vegetable gardening, herb gardens, or any other plants you fancy growing from seeds.
Here are the biggest mistakes you should avoid when starting seeds
don’t allow tons of seed starting ‘information’ to confuse you
There is so much information about starting seeds on the internet and in books/magazines that is not only repetitive, but also conflicting, depending on the author. My suggestion is to dabble around, pick the resource that resonates with you, and stick with that. You’re going to end up changing your seed starting routine as time goes on, so don’t let too much information bog you down and prevent you from ever beginning. Just go for it! You’re going to make mistakes, and you’ll learn so much along the way.
Here’s where I get my seed starting information:
Johnny’s Selected Seeds, for quick seed starting information on specific varieties
“Specialty Cut Flowers: The Production of Annuals, Perennials, Bulbs and Woody Plants for Fresh and Dried Cut Flowers” by Allan Armitage - the most comprehensive book
Related: Favorite Gardening Resources: Books, Tools, Fertilizers and More
don’t complicate the seed starting soil mix
Soil is one part of the seed starting process where everyone has a different method. It’s taken me a few years, but I’ve finally figured out what works best for my setup. Some farmers will use a mix of several soil bases and fillers, and they will continue to fertilize their transplants every week as they grow (Fish Emulsion is the preferred fertilizer for flowers and vegetables). While I’ve used Fish Emulsion as both a foliar spray and water drench, it is way too stinky for my indoor growing space.
My seed starting mix consists of two ingredients: 4 parts Organik Pro-Mix with Mycorrhizae Potting Soil to 1 part Alfalfa Meal. I’ve found this mixture to be pleasantly light and fertile enough that I do not spend any time fertilizing my transplants until planting day.
Please note, you grow edibles, you may want to consider a fertilizing regime to increase the nutrient density of the food you’ll eventually be eating.
Related: How Compost Works and How to Make Compost in Your Backyard
don’t use a window as your light source — buy led shop lights
When people share their seed starting struggles with me, the first thing I ask is what they’re using for a light source. More often than not, they are simply using a window and relying on four hours of early Spring sunlight to get their seeds going. Big mistake! You need to invest in lighting. I highly recommend using white LED lights which are much more efficient and sustainable than their vanishing fluorescent counterparts.
Read our DIY Seed Starting Setup article to learn ALL about LED lighting.
LED lights give off enough spectrum for plants to be happy. You can buy a simple LED shop light to get started.
Pro Tip: Use a timer for your lights so you don’t have to turn them on and off everyday. I use this mechanical outlet timer to have the lights on for 16 hours every day.
Related: 5 Steps to Building Healthy Garden Soil
perennial seeds are temperamental — give them what they require to germinate
Most, if not all, Perennial species require a dormant cold period in order to cue to the seed to germinate. This process is known as Vernalization. You can mimic an outdoor winter dormancy by putting your seeds in the refrigerator 8 weeks prior to starting them. My preferred way to vernalize perennial seeds is to fill a takeout container with wet potting soil, sprinkle the seeds on top, put the lid on it and store it in the refrigerator for 8 weeks. After this period, place the container underneath your grow lights and wait for sprouts to emerge (keep the lid on before sprouts emerge — this will hold in the heat required for germination). When the seedlings are big enough, you can then separate them and pot up into 4-packs or larger containers.
Related: On Planting Perennials
don’t treat every seed the same
Another easy mistake to make is treating every seed the same way. Along your journey, you will learn either the hard way or the less-hard way that every single species of plant (and often times, different varieties of the same species) have differing germination requirements. Some seeds require darkness and must be covered with soil while some require the light to germinate and if you cover them, they simply won’t grow. Some seeds prefer cooler temperatures than others. Some seeds take 3 days to germinate while some will take an entire month.
Researching information about every single type of seed is important for your success in seed starting. Make yourself a spreadsheet that includes the plant species, variety, days for germination, weeks to start before planting, whether the seed requires light or darkness, and any other special needs. I gather most of this information on Johnny’s Selected Seeds by searching the specific variety and reading about each one — all the information you need is there for you to glean, for free.
Related: The Reason Why Synthetic Fertilizers (like Miracle Gro) are so Bad for your Garden
don’t allow conditions for mold to grow
When your soil mix is consistently too wet, white mold will eventually form. This happens to me here and there. Fungus won’t necessarily kill your plants but it sets them up for weakness and “damping off,” which is a disease caused by fungus. You should always try to keep your plants moist, not sopping wet. A fan helps to circulate air and keep the soil drier (and will also subsequently make your plants stronger as they sway in the fan’s wind). I also use a HEPA air purifier in my seed starting room, to remove mold spores from the air, should they be present.
If you’re growing in plastic trays, 4-packs or 3” pots, you usually will only need to water every 3-4 days. Soil blocks dry out much faster, especially 3/4” soil blocks, and must be watered daily.
If you do experience damping off or fungal issues, it is best practice to toss the plastic trays after use, or bleach them VERY well before reusing.
Related: How to Start Seeds with a Mini Soil Blocker
Don’t work from memory — keep a seed starting spreadsheet
The best thing you can do for yourself is to keep a spreadsheet of growing information every season.
I use Google Sheets for this. For each type of seed, I have the following columns:
Main Type (ie. Zinnia)
Specific Variety (ie. Queen Red Lime)
Plug Cell Size (50, 72 or 128)
Number of Trays to Start / # of Plugs
Light vs No Light Required for Germination (mark with an “X” if light is required; easy reference on seed starting day)
Seed Starting Date
Number of Weeks to Planting Out (This describes how many weeks in advance to start seeds from planting date, remember to ADD one week for hardening off, or however much time you prefer for hardening off)
Planting Out Date
Actual Days to Germination (recorded after germination; I record this because I’ve found my seedlings tend to germinate much faster than the seed packets claim and this helps with future date planning)
Bed # or Location of Planting in Farm (helpful for crop rotation)
Number of Plants ACTUALLY planted in field (recorded after planting; I record this because sometimes plants break or are doubled up in the cells and I end up with more or less than expected. Knowing exact number planted informs whether I had enough or not enough yield.)
“Field Notes” (Here I keep a very detailed record of how each crop did in the field. I take note of any pest/disease issues, how they responded to fertilization, general notes on yields, etc)
If you’re brand new to seed starting, all you can do is begin and learn from your mistakes. Don’t be afraid to make mistakes, because it’s inevitable that you will. If you have any questions, please leave a comment below!
peace, love and seedlings,
Fran Parrish
