For germination to occur, conditions both inside and outside the seeds must be favorable. All seeds need water and air.
Most have a specific temperature range that they like best. For example, lettuces like cool temperatures to germinate, while tomatoes do better in the 75 degree range.
Many seeds, especially smaller ones like petunias and begonias, require light to get started.
Some seeds benefit from a dramatic change in the internal or external environment to help break dormancy.
For example, parsley germinates better if you soak the seeds for a week before planting. Snapdragons and carnations benefit from putting the seed packet in the freezer for a day or two.
Geraniums need to have their seed coats cut to allow moisture in (although many geranium seeds come with this already done).
The seed packet should indicate the best germination temperature and whether any pretreatment is required. It should also state the year for which the seeds were packaged.
Some seeds can be stored for many years, while others lose their viability quickly. Until you get some experience, using fresh seeds will improve your chances.
The seed packet will also tell you how far in advance of the last frost date to sow the seeds indoors.
The traditional last frost date in Haywood County is May 15. Planting too soon results in plants that are too large to transplant easily. Planting too late delays flowering and fruiting.
If no planting depth is recommended on the packet, cover the seeds only to their thickness. Don’t cover very small seeds at all.
Separate seeds by a half inch or so; this will make transplanting easier. Cover the seed flat with clear plastic to keep the medium from drying out. Place in a tray with enough water in it to cover the holes in the bottom of seeding flat.
After the seedlings emerge, remove the plastic cover. When the first true leaves (“second leaves”) appear, transplant into pots at about the same level they were growing in the seed flat.
Use a plastic knife or pointed craft stick to dig out a seedling, picking it up by the leaves (holding a seedling by the stem may permanently damage it).
You can plant some seeds directly in the pot that the seedling will grow in without transplanting. For example, sow three tomato seeds in each pot, then snip off all but the best seedling.
Sowing directly into pots is best for hard-to-transplant varieties; check the seed packet for information.
Fertilize every two weeks with half-strength liquid fertilizer. Add water and fertilizer to the tray (instead of pouring on top of the seedlings, which can displace enough medium to expose their roots).
Grow the seedlings in a brightly lit area (fluorescent lights are ideal), but not in direct sunlight.
Remember that cleanliness is essential in your indoor greenhouse. Maintain this area as if it were your kitchen. And don’t go on an extended vacation. This isn’t a whole lot of work, but it does require at least a couple minutes of attention every day or two. Seedlings allowed to go bone dry will not be happy.
The last article in this series will highlight plants that are easy to grow from seeds.
Jim Janke is an Extension Master Gardener Volunteer in Haywood County. For more information call the Haywood County Extension Center at 828-456-3575.