NDSU Extension - Dickey County


| Share

Starting Seeds Indoors

Breana Kiser, Agriculture and Natural Resource Agent

Starting Seeds IndoorsThe other day my sister asked me “What does she need to start seed inside?” With all the snow and the temperatures slowly rising, I thought that it was a great idea to start thinking green and getting ready for warm, spring weather.
So to help out all of those gardeners who will be trying to have their first garden this summer and even to help some experienced gardeners, here is some helpful tips.

The benefits of home-started seedlings are having a much greater variety of vegetables, flowers, and herbs to choose from than if you just go down to the local garden center to pick up six-packs of nursery-raised starts. Growing your own seeds will allow you to choose varieties to bloom earlier and harvest earlier along with getting a fuller crop stand.  Starting your own seeds allows you to give your starts special personal care, and time your plantings so the seedlings will be ready to go into the ground at just the right time for your area.

Where to start? When figuring when to start your seedlings you have to consider your timing. The timing of when you start planting your seedlings to raise is an important question. Gardeners time their plantings relative to the average date of the last spring front in their area, for this year those dates are; Ellendale is May 5 and Oakes is May 9. Depending of the plant you are growing the sowing date is a number of weeks before the last frost date. Tables of the time can be found online or in the NDSU Extension Publication How to Succeed at Seed Starting.

Once you know when to start, the next step is what is needed for seeds to grow. First step is to make sure you have an appropriate growing medium for your plants. Inappropriate mixes can get rock hard after a few waterings. Your mix has to stay light and friable. Don’t use plain garden soil! Some types of seed starter mix include peat moss, compost, and perlite are the optimal selection but potting soil is acceptable as well. Your planting mixture can be put in cutoff milk cartons, deep-sided disposable aluminum pans, or special seed-starting systems. They should be at least 3 inches deep for roots to grow and have small holes for drainage. Many gardeners prefer to make traditional wooden flats (14” by 12” by 6” is a good size). Leave about 1/8-inch gap between the bottom boards so extra water can drain out, and then cover this base with newspapers or a thin layer of leaves to keep the soil from draining out.  

Generally, seeds germinate better is their soil temperature is constantly 70°F or above. Keep the seed trays in a constantly warm place. Look for any warm spot you can find. Do not put seed starting trays in a windowsill; it is almost always much too cool for good germination, particularly at night and the morning. Maintaining consistently warm temperatures, both day and night, signals the seeds to begin growing. Probably no other factor will speed up germination time more than a constant warm temperature. As insurance, you may want to go to the extra step of buying a bottom-heating seed propagation mat.
Seeds also need to be kept constantly moist in order to germinate. Never let the germination media dry out. Therefore, the mix should be kept moist, but not too wet; the consistency of a wrung-out sponge is about the right and a good standard to use. Moisten media thoroughly before sowing, mix it well to distribute moisture evenly, and be sure it doesn’t dry out afterwards. One easy aid is to drape a sheet of plastic wrap on top of newly planted seeds to keep moisture in. Be sure to check every single day to see if any seeds are starting to sprout. If they are, immediately remove the cover so they can get some light and air circulation. Water as often as needed from above, but don’t just pour water on unrooted seeds or they will wash right out of the soil mix. Use a plastic spray bottle or a watering can with a very fine, upward-pointing hose so the drops will fall very lightly on the soil. If the seedling tray has a plastic cover that is available, lift it up to water, then lay it down again. Check often. The water should be at least room temperature. It is advisable to allow any chlorinated water to stand for a day to allow the chlorine to dissipate.

Most seeds don’t need light to germinate, just warmth, moisture, and darkness. After the seedling appears above the soil, then light is necessary.

Fertilization is not necessary for seeds either, since they carry their own food and have enough food energy to germinate on their own. Young seedlings however will need a weak fertilizer to grow successfully.

Now how do you actually grow your own seeds? Fill containers almost to their brims with moistened soil. Smooth it out and tamp it down. Then begin carefully setting the seeds in, planting them shallow. Seed packets inform how deep to sow seed – be sure to read them carefully.

To keep better track of planting areas, set all the seeds on the surface of the flat and then sift extra soil mix on top to cover them. With tiny flower seeds like petunia and begonia, simply press them into the surface and then cover with a sheet of clear plastic wrap. If individual containers are being used, put only a couple of seeds (the extras are for insurance) into each container. With flats, space seeds a half-inch apart if the intention is to transplant them to a second grow-out flat later, or 1 to 2 inches apart if they are going to be kept in the same flat until garden time. It is always best to plant more seeds than what is needed. They may not all germinate, and it is best to have many seedlings so only the healthiest are chosen. Thin out the smallest and weakest ones later.

If more than one type are planted in a tray or flat, choose ones that have about the same germination time and transplant date. Again – read the packet backs for this information. Don’t forget to label each variety as the seeds are sown. It is now time to set the trays in that warm spot and to make absolutely sure they are evenly and consistently moist.
Check them every single day. The minute some pale seed heads start to pop out of the soil, rejoice! The miraculous cycle of growth has begun.

If you would like the publication How to Succeed at Seed Starting, contact the office to get a copy or for questions call to visit with me. Happy planting!      

Creative Commons License
Feel free to use and share this content, but please do so under the conditions of our Creative Commons license and our Rules for Use. Thanks.