Seed Starting Tips from Bloom!

Posted on February 22, 2016

Bloom! Gardens & Nursery -- Get Ready for Spring Gardening - Seeds from the Seed Library

Indoor Seed Starting


There comes a time every year for us Michiganders, where we are no longer enjoy the snow and cold weather. Our once excited glances out the window at white wintery wonderland turn into angry stares at the frozen piles of snow. Fortunately, for gardeners, this time of the year coincides with the time to start seeds. Each seed contains hope that spring will return, and a promise of warmer weather. Living in Michigan can pose some challenges to seed starting.  Using the tips on this guide you should have great success.

1. Pick out your seeds:


Each seed packet contains all the information that you will need to know for success.  

seed starting front

For beginners, reading the back of your seed packet is crucial. It gives valuable information of when you should plant your seeds indoors.  This is a summary of the most important information:

seed starting back

Plant or Row Spacing: How much space your adult plant will need to successfully grow.

When to plant indoors: When you need to sew your seedling indoors.  In Michigan, we want to give our seedling as much time as possible to grow indoors. In the example below, we would want to start these tomato seedlings 8 weeks before the last threat of frost. This would be the second week of March.

When to sow outside: Some vegetables are cold weather crops and can be planted earlier than the last threat of frost. Most plants need warmer soil temperatures and for the threat of frost to be over.  If you sow your seedlings too early, they will not be strong enough to withstand cold temperatures.

Days to Emerge:  For impatient gardeners like me, this lets me know when I will start see sprouts.   


The back of the packet also contains valuable information like what you will need to grow your plants.  It will tell you if trellises are needed or if you plant will need to be grown on hills.


It is also very important to know the outdoor area where you will plant your seedlings. If you do not have enough light, you will have sub par results. On the other hand, if your area gets too much sun, the plants will be subject to burns. You can find the light requirements for you plant on the seed packet.


2. Choose your growing soil and container.


I prefer to use a seed starting mix or Jiffy pellets.  Seed starting mix is a specially formulated to keep appropriate amounts of water in the soil. It is different than standard potting mix. It contains coco fiber and vermiculate, which helps protect against rotting and different fungi that seedlings are prone to.  

I am also a fan of organic seed starting mixes.  Seed starting mixes that are not organic and contain fertilizers, can have slow release chemicals that are stored in the cells of the plants and will present in the fruit, vegetable, or flower. This means that the chemicals are consumed in the body. I am also cautious to use good safe soils and fertilizers in my home so that animals and children are safe in case of an accidental spillage.

3. Natural Light vs. Grow Lights


If you have a good window or greenhouse that receives 6-8 hours of bright warm sun, then you do not need a grow light. HOWEVER, this is not the case for most Michigan homes.  Unfortunately, if your seedlings are grown indoors and put next to a window, the likelihood is that your seedlings will not get the appropriate amount and spectrum of light. Visible light is comprised of a spectrum of color.  Plants need different spectrums of light at different growth periods. For example, a baby sprout needs a different spectrum of life than a 3 or 5 week old seedling.  

One of the most common problems that I hear when starting seedlings indoors is that plants will grow really well for 2 or 3 weeks, and then they will start growing too tall and the stems will be too thin and fall over. This usually occurs when the seedling is grown in a window and does not receive the correct spectrum of light.  The only way to combat this is to purchase a grow light.  A good grow light will have a full spectrum of light. There are a lot of grow lights out there, and you don’t have to go crazy with research.  I would however avoid the cheapest of grow bulbs out there that are $3 or $4. These grow lights usually do not have the full spectrum of light and will also cause your seedlings to grow long and lanky.

Once your seedlings sprout you can begin using a grow light. You do not need to keep your grow light on all night. Turning your grow light off at night will give your plants a chance to rest at night.

4.  Heating Mats


Another common problem that I hear quite a bit is that after a week that the plant stops growing. The seedling stays small.  This is due to cold temperatures. Seedling heat mats are appropriately sized to fit under plastic seedling trays. The mats provide the right amount of heat so that soil temperature remains at an optimal growing condition. It also helps for gardeners who start seeds in their basement or colder areas.  A heating mat can be a luxury and may not be necessary, but it ensures that you plant will continue growing.

With these simple rules and tips you should have great success at starting seedlings. If you do have questions, please contact us! We would love to help!


– Virginia, Bloom! Horticulture Specialist & Inventory Manager