Seedlings need a lot of light to grow into sturdy, healthy plants. No matter what anyone tells you, chances are that you do not have enough natural light in your home to grow robust seedlings. Even a south-facing window usually will not do. You can, however, use artificial light to achieve the right amount of light required by seedlings. To do so, obtain grow lights explicitly designed for plants. Or, for a more economical solution, purchase large fluorescent shop lights outfitted with one warm bulb and one cool bulb.
To be able to identify seedlings as they grow and to know when they will be ready for transplanting, you should label the seed containers as you are sowing. For every type of seed sown, use popsicle sticks or plastic plant markers and permanent ink pens to record the plant name and date sown. Insert the plant labels into the soil near the edge of the container or tray.
Watch Now: Mistakes to Avoid When Growing Seeds Indoors
To increase your chances of getting it right, here are a few things you can do:
The Spruce / K. Dave
The Spruce / K. Dave
How to Transplant Seedlings
Plant seedlings out while they are still quite young if outdoor conditions allow—sometimes as soon as three to four weeks after sowing. Younger seedlings tend to establish quicker than those that have become root bound in their containers.
If you grew seedlings all together in a tray, you can transfer them into their own plugs or pots of potting mix. Start pricking them out as soon as the seedlings are big enough to handle.
VIDEO : Demonstrating Hardening Off
Once you’re done, gently water the seedlings with a watering can. Don’t worry too much if the seedlings get a little flattened, they’ll soon recover.
Each option has its advantages and disadvantages. Buying transplants is certainly a lot easier and more convenient, but you are also limited to only growing the types of vegetables and flowers that you can find. Seeds, on the other hand, offer a wide range of varieties to try. Here are the main things to think about:
For seed-starting information customized to your location, check out our free online Planting Calendar.
Hardening off should take a minimum of a week and may take up to two. Suddenly moving plants from a stable environment to one with wide variations in temperature, light and wind can seriously weaken plants.
Soil Blocks are a compressed or formed cube, made from a soil medium typically consisting of a sterile mix and compost.Well-known organic farmer, Eliot Coleman is a huge fan of using soil blocks for all his indoor seed starting. (We filmed an episode with Eliot for our television series where you can watch him working with soil blocks in his greenhouse.) A big appeal for fans of soil blocks is that you’re not using plastic or pots or unnecessary packaging.
These mixes are fluffy and light, therefore root systems thrive, and the mix dries out quickly which means soils won’t be waterlogged. There is also less chance of fungus problems like damping off.
Some seeds germinate and grow so quickly; there’s no reason to take up indoor space to start them early. Corn and beans are good examples.
Simple Steps to Sowing Success
Check the back of the seed pack or with your local cooperative extension service, or online guides for information on the optimal temperatures for germination of seed varieties.
These tomato seedlings are getting their first sun exposure. This gradual process is known as “hardening off.” (Photo: Craig LeHoullier)
A heat mat is a thin, reusable, waterproof mat that is placed under the seed tray. It’s an excellent resource to raise soil temperature into the preferred range. The heat from the mat will increase the germination rooting area soil temperature about 20F.
A single layer of plastic wrap draped over seed trays is an efficient and inexpensive way to trap moisture until seeds germinate. Heat mats placed under the trays aid in rapid germination. (Photo: Craig LeHoullier)