Hello Steve,

The answer is the same as most gardening questions – it depends… There are several variables that lead to success (or failure) related to vegetable seed propagation. It may be difficult to find one definitive article describing what you are looking for, so you may need to perform several searches to find all the information you need for success.

Speaking as a grower that propagated vegetable seeds indoors in Oakland county for 20+ years, it is not a simple (nor inexpensive) task to obtain high germination rates and strong transplants. Here are the factors that affect seed germination:

Growing medium - Growing medium should be a soilless, sterile seed starting mixture and your growing containers should also be sterilized. Organisms in the medium or on the containers can cause infections that can kill the seedlings.

Fertilization – Since these preferred growing media contain no natural nutrients, feeding your seedlings with a dilute liquid fertilizer produces a much stronger transplant. Fertilizer should be applied based on the size of the seedling. Please see reference material below.

Growing medium temperature – Each seed type has a minimum, maximum and optimum medium temperature at which the seeds will germinate. Medium temperatures outside the optimum range can result in low germination rates or total crop failure. Bottom heating of the growing medium greatly increases success rates of germination. See the temperatures in this article: https://www.aces.edu/blog/topics/lawn-garden/soil-temperature-conditions-for-vegetable-seed-germination/

Watering (overhead or bottom) – Overhead watering of young seedlings can result in unnecessary disturbance of the growing medium and seedling roots. Bottom watering (flooding a water tight tray below the perforated growing container) yields higher success rates. However, the flooding tray must be emptied after the growing containers have taken up enough water. Also, if you are using starter plug trays with low medium volume, they tend to dry out quickly at the correct medium temperature and the correct light intensity. This is why humidity domes are often used to control moisture loss.

Light (Color and quality) – Artificial light needs to be in the correct color spectrum and must be the correct intensity (closeness) to the seedlings to prevent them from becoming leggy and spindly. Even greenhouses in Michigan require supplemental artificial light during the seedling season (March to May) to provide intense enough light to grow strong seedlings.

Germination and growing time – Each vegetable plant has an estimated “time to transplant” that indicates when the seeds should be started. For example, in our area, tomatoes should be sown 6-8 weeks before transplant. To place them outside mid to late May means that they should be started in early April. Number of weeks before transplanting time is generally provided on the seed packet.

Now to the “Depends”… What are you planning to grow? Warm season veggies like tomato, pepper and cucumber require higher germination temperatures and intense light levels, so they may or may not thrive in a greenhouse without supplemental heat and light. If you are growing cool season crops like broccoli, cabbage, lettuce, peas, you may have perfectly acceptable luck with a greenhouse or even a cold frame, depending on our spring weather. This probably isn’t the answer you wanted, but unless you want to grow a specific cultivar that is not available at a local plant source, or you just want to experiment with the factors that lead to transplant success, it is much easier and often less costly to buy your seedlings at a commercial grower, rather than starting your own.

Here is a good general reference concerning starting seeds indoors:

https://extension.umn.edu/planting-and-growing-guides/starting-seeds-indoors

Here is an MSU article about starting warm season vegetables indoors:

https://www.canr.msu.edu/news/time_to_start_vegetable_garden_seeds#:~:text=Keep%20soil%20temperatures%20between%2075,that%20are%20leggy%20and%20stunted.

This article would help you troubleshoot problems with seedlings:

https://extension.illinois.edu/blogs/good-growing/2022-02-25-whats-wrong-my-seedlings-troubleshooting-seed-starting-problems

Thank you so much for the thorough, yet understandable, advice to a total newbie. Appreciate all of your insights and additional resources.

Do you have advice on finding a commercial grower who would sell seedlings in small quantities (for home gardening)? I'm not sure if this is simply local plant nurseries or a more specialized grower. I imagine not the local hardware store...

Thanks again! 

 

Hello Steve,

MSU’s policy is not to promote any one business over any other, so I cannot recommend specific growers. I can, however, point you to the following database of landscape professionals:

https://www.plantmichigangreen.com/aws/MNLA/pt/sp/home_page

If you choose “garden center” and enter your zip code, you will find several growers where you can buy anything from single plants to flats (~48-ish) of vegetable transplants. When I tried my zip code, all of my “go-tos” were listed.

Actually, in the spring you will be able to find vegetable starters at your local nurseries, as well as “pop-up” retailers who set up at roadsides, in local big box stores and garden centers, and in local farmers’ markets.

The plants at local big box stores and hardware stores are of no lower quality, but their care (read “watering”) may not be as diligent as at garden centers.

Beyond that database, I would suggest looking at online reviews of the garden centers you would like to try. Also, look at facebook for groups in your area. I am sure you can find a local gardening group that can share successes (and failures).

Wherever you choose to buy your transplants, examine the seedlings to make sure they look healthy (good color, strong stems, not too leggy), insect free (look under the leaves), and appear to be well cared for (not wilted from lack of water, not sun burned or frost burned from being set out too early). Here is a reference on finding good transplants:

https://www.canr.msu.edu/uploads/files/E3175_-_Selecting_Healthy_Transplants.pdf

One final suggestion… If you get bitten by the vegetable gardening bug, consider taking the Foundations of Gardening class from MSU. That’s how I started my journey 30 years ago; it led me to where I am now.

https://www.canr.msu.edu/courses/foundations-of-gardening