Here in Florida, autumn is a great time to start seeds. Seed starting helps you get more plants for less money and is a good way to acquire unique plants not available locally. Many seeds can be started outdoors, in the garden areas where they will grow. However, I have had the most success starting seeds indoors in containers and moving the new plants out into the garden. And it’s fun to make your own plants!

Source Your Seeds

Some native plant nurseries sell seeds, and many varieties are available by mail. The Florida Wildflowers Growers Cooperative (floridawildflowers.com) and Florida Native Wildflowers (floridanativewildflowers.com) are two sources for native plant seeds and helpful seed sowing information.

If you already have a plant in your garden and want more (or if you have a friend or neighbor willing to share), seed collecting is another option. Instead of deadheading, leave the spent flowerheads on the plant. Seeds are ready when they turn brown or black and release easily from the seedpods. If you wish to trim back the plants before the seeds ripen, place the spent stems in a paper bag. Once the stems are dried, gently tap them on a paper towel to separate the seeds from the chaff. For later sowing, place the seeds in a paper bag or envelope and store in a cool, dry place.

Do Your Homework

Some seeds require special treatment to perform their best. For example, seeds of coral bean (Erythrina herbacea) have a hard coat and require scarification, weakening of the seed coat, so germination can occur. Carefully nick each seed with a sharp knife, soak the seeds, or rub them on a coarse piece of sandpaper. The seeds of butterfly weed (Asclepias species) benefit from a simulated “winter” period, called stratification. Wrap the seeds in moistened paper towels, place the bundle in a freezer bag, and store it in the refrigerator for several weeks. Read the seed packet or do a bit of internet research to gather specific information for the plants you wish to grow.

Collect Your Containers

If it can hold soil and has holes for drainage, most any container will work. Reused plastic pots are useful, but I have also repurposed plastic restaurant takeout containers, yogurt cups, etc. Just be sure to thoroughly clean any reused container with a mixture of one part bleach to ten parts water, and rinse well. And be sure to punch holes in the bottom to provide adequate drainage.

Prepare the Soil Media

Fill your container with potting mix, which is available at a garden center or big box store. It is often called “soilless” mix because it does not contain outdoor soil nor any weed seeds or insects that could interfere with plant growth. Instead it is a sterile mixture of components—such as perlite, vermiculite, and peat moss—that provide support for emerging seedlings. Before beginning, ensure the mix is moistened but not saturated. A proper mix will have the moisture content of a wrung-out sponge. As you fill the container, tap it gently on your work surface to settle the soil. Be sure to fill each container almost to the brim. If seeds are sown too low in a pot, the rim casts a shadow, limiting the amount of light that can reach the developing seedlings.

Sow the Seeds

Make a shallow hole in the soil, place the seeds where you want them, and cover, tamping down the soil gently. Be careful not to sow seeds too deeply. A good rule of thumb is to sow any seed at a depth of no more than two times the thickness of the seed. Tiny seeds should be sown on the surface with additional soil very lightly dusted over them; larger seeds can be covered with a little more soil. If the seeds require light to germinate, gently press them into the soil, but leave them uncovered.
 
After sowing the seeds, cover the container loosely with plastic wrap to maintain soil moisture but allow some air movement. Place the container in a warm spot but not in direct sun. Don’t forget to add a popsicle stick or attach a sticky note with the plant’s name so you remember which seed is in which container. (Yes, I have made this mistake!)

Check the container each day and mist it if the soil appears dry. Once the seeds germinate, remove the plastic wrap. First to appear are the seed leaves (cotyledons). The seed leaves provide an initial burst of energy as the seedling begins growing. As its growth continues, the seedling will put out true leaves, which resemble the leaves of the mature plant.

Grow the Seedlings
Place the container near a window where it can receive good light. If you notice the seedlings beginning to lean toward the light, rotate the container. If you plan to do a lot of seed starting, you may wish to purchase a light system or build a simple wooden stand with a fluorescent shop light suspended by lengths of chain attached to hooks. This system allows you to raise the chain and lift the lights as plants grow. Place the lights so they are no more than two to three inches above the plants. Otherwise, plants will stretch and weaken as they attempt to reach the light.


Be sure to watch the container daily to ensure the seedlings do not dry out. Mist or water gently if the soil appears dry. Bottom watering can also be useful. However, it is important that the container does not sit in water, or the plant roots may rot.

Transplant the Small Plants

After true leaves appear and the seedlings begin to get a little larger, you should transplant them. This will ensure each small plant has adequate room and proper air circulation. You can use individual small pots or flats that are capable of housing multiple small plants, one per cell. Carefully loosen and separate the seedlings. Place each in a separate clean container or cell filled with moistened soil mix. Try to retain a little soil around the roots to limit the plant’s shock. Once transplanting is complete, place the pots or flats back in the light so the plants can continue to grow.

Get Them Garden-Ready

Because the sun is so strong here in Florida, new plants must be sturdy enough to survive. When your plants have reached sufficient size, you can toughen them up with a gradual exposure to direct sunlight. This is called hardening off. Start by putting the containers outdoors in the shade. Then, move them into the sun, starting with short periods and increasing their time in the sun each day. Be sure to keep the plants moist and watch them closely. If you observe any signs of wilting, bring the plants into the shade, and begin the process again more slowly.

Plant Them Out

Once the new plants have gained sufficient size and strength, they will be ready to move to their permanent home in your garden. However, even when plants have been hardened off, moving can still be stressful for them. To reduce transplant shock, try to choose a cloudy day or when rain is in the forecast. My favorite solution is to provide new plants with a sunshade for the first day or two. I cover small plants with an upside-down flowerpot. For large plants, I move the garden furniture to cast some shade for them. The new plants will soon begin to thrive in your garden. And you will have the satisfaction of knowing you made them yourself!