Starting your own plants from seed is one of the most rewarding gardening experiences, it can also save you a small fortune! Also, many species and varieties are simply unavailable unless you "grow-your-own".
Choosing seeds is the first step, there are many reputable companies that offer catalogs, besides the fun of browsing through them, mail-order companies are generally good about dealing with any problems you might have. In buying seeds through retail outlets,it's a matter of "buyer beware" ,those 10/$1 seeds may not be such a bargain if they don't grow! Check the package for date,and complete growing instructions,a reputable seed company will also list the Latin name and germination percentage you can expect.If you've acquired seeds from GardenWeb swaps,or other seed sources ,ask for any info the grower can give!
You can use most any container,as long as it will hold 3-4 " of growing medium and has drainage holes in the bottom. Flats with liners are nice,but "recycled" containers will do, if you're reusing containers, follow the cleaning instructions under "what is damping-off?".
Seeds need a loose,porous,fine-textured medium, one that won't develop a "crust" on the surface that can interfere with emergence .
"Potting soil" is an extremely variable product, many retail brands (especially the "bargain" types)will give disappointing results in seed-starting! A "soil-less" mix will make your growing experience much easier.
Some common ingredients in soil-less mixes:
Vermiculite, a heat-expanded rock, can be used alone or in combination for starting seeds.
Milled sphagnum moss (NOT the same as peat moss unless it says"sphagnum peat")has the benefit of inhibiting damp-off fungus, mixed with vermiculite it is frequently used by professionals.
Peat moss(sometimes called "Michigan peat" or "peat humus")a heavier,more difficult to wet and more variable product than sphagnum moss ,is common in retail mixes sold for starting seeds,often in combination with perlite or vermiculite,it's often(much!) cheaper than sphagnum-containing mixes but can be more difficult to handle,especially for the beginner.
Don't start seeds too early,there's a wide variation in optimal indoor starting times,and unless you have lots of room,starting too early can be stressful,for you and your plants! You may want to consider starting perennials in summer for Fall planting,as many perennials don't bloom the first summer,to save room for annuals and veggies that really need a head start in temperate climates.
Sowing seeds: Fill containers,allowing an inch or so from the top for easier watering, and moisten well. Allow excess water to drain, medium should be moist,not soggy. Press the medium down lightly to eliminate air pockets.
For plants that don't mind ,or even benefit from transplanting, like tomatoes and lettuce,a number of seeds can be planted in larger containers and transplanted to individual pots when seedlings are large enough to handle. For those that dislike transplanting ,such as melons,or to save yourself time later on,plant 1-3 seeds in individual containers,snip off all but the strongest seedling with scissors.
Sow the seeds on the surface,and cover with additional dry medium to the proper depth, a general rule is twice the diameter of the seed.Very tiny seeds,or those requiring light are surface-sown without covering. Mist the medium well and cover with clear plastic , a 13-gallon clear kitchen trash bag fits a standard flat perfectly(I buy the kind with the handles and tie them loosely)Don't put an enclosed container like this in direct sunlight!!
A temperature of 65-75 degrees is suitable for the vast majority of common plants,but there are many exceptions,too many to list here! Check at least daily,and remove the plastic when seeds begin to sprout. Place under bright light ASAP!
Seedlings need intense light to grow strong and stocky,fluorescent lights are your best bet (see "do I need special lights?") Position so that seedlings are 2-4" from lights, 14-16 hours a day. A timer will help automate the process. If space under lights is limited,you can try rotating them under lights in 12-hour shifts. Keep a close eye on them and adjust heights as needed.
Containers enclosed in plastic should not require watering until seeds germinate,once plastic is removed monitor closely,seedlings should never be allowed to dry out completely,and should be kept moist until roots begin to penetrate the medium. Allow the medium to become dry 1/4-1/2" down before watering thereafter,to allow air into the medium and encourage roots to spread.
If you've used a soilless mix, begin fertilizing 4-5 days after germination with a water-soluble 15-30-15(or similar ) fertilizer at half the recommended strength,and weekly thereafter. I've had good results with fish emulsion and seaweed extract at recommended rates,for those interested in growing organically.
For growing on info see"OK my seeds are growing...?"
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