For most people seed knowledge begins and ends with the common vegetable seed that can be popped into the soil, covered over, watered and then left to do whatever it is that seeds do. If you look around you at every living plant and tree you can see, then become aware that almost each one began as a seed. There are a few exceptions...plants that can only reproduce vegetatively or by sending out runners from their roots, but they are indeed very few compared to the rest of the plant world.
The most common scenario involves a new seed enthusiast who purchases a few packets of assorted seeds with visions of country garden magazine layouts springing to life on their own little acre. That wonderful dream is usually skewered on the reality of time and failure. Time and patience are required for a plant to reach maturity from seed and especially for perennials (the plant comes back each year) as they often do not bloom until the second year from seed. Failure because the seed packets do not give the correct germination information. Seed companies are notorious for misinformation or incomplete information which, when you think about it, is absurd. Their business depends on their customers having the most positive experience or they probably won't return. Usually the poor customer places selfblame and begins to insist he/she simply can't grow plants, when nothing could be further from the truth.
There are basically three types of plants with some subdivisions occuring as part of each.
Annuals (further subdivided by hardy and tender; they bloom, set seed and die in one year)
Biennials (set out a leaf structure the first year and bloom and seed the second year, then die)
Perennials (returns every year from its root system and is further divided into hardy and tender varieties)
There are also plants which behave as triennials by producing foliage for two years and then flowering and setting seed in the third and then dying off. Even among perennials there is a lifespan. Some are known as short-lived perennials, lasting perhaps four or five years and yet others can live seemingly forever.
Moisture is the essential ingredient. It must be kept constant. If the soil dries out, the seed dries out and dies. Whatever type of container you use (pot, peat pot, flat, cleaned meat tray, etc) use a plastic or glass cover and set in bright light, but not direct sunlight as that would create too much heat in the container. Insert the container into a plastic bag to create a tent and use a twist tie to seal the end until germination occurs. At that time remove the twist tie to allow air flow but do not remove the bag entirely for 24 hours. Watch the moisture level after the bag or cover is removed and do not allow to dry out. Plastic domes are sold for commercial flats and any piece of clear plastic or glass can serve as a cover. Even an old glass fish aquarium can serve as a mini greenhouse.
For the most part annuals are pretty straight forward, but many of the flowers require time to develop. Most flowering annuals you wish to enjoy for their beauty should be started inside 6 to 8 weeks before setting out or the flowers will not appear until the end of summer and their enjoyment will be shortlived. It will certainly not be the experience you hoped for.
Once the plants have begun to develop you will need a way to harden off. This is a simple process of getting the plants accustomed to being outside. A cold frame can be built out of scrap materials or hay bales and either a section of glass or greenhouse plastic used for a top. During the day the top is lifted and at night it is closed to protect the plants from severe changes in temperature. After a week or two the plants can be safely planted. Lacking a cold frame, the seedlings can be placed outside on a porch during the day and brought back inside at night for a week or two.
Two things are vital:
They must not be subjected to direct sunlight immediately; do it gradually or they will suffer from sunburn.
They must not be subjected to stiff breezes as they will be fragile until their stems thicken. Protect them.
When starting seeds indoors, the object is to reproduce as nearly as possible the conditions that the seeds require in nature to germinate. For many perennial seeds that means a period of cold (called Stratification). Some seeds require dark and others require light. Some seeds are so hard that the only way to get them to cooperate is to nick them or soak them. The following numbered items (according to their number) will be found in the seed charts next to seeds that require that treatment.
Nicking or Scarifying: some seeds have a very hard seed coat which makes it difficult for them to take up moisture. Chip the seed with a sharp knife at the part which is furthest away from what appears to be the eye of the seed. Or rub lightly with sandpaper. If the seed is small, then rubbing a small amount of seed between two pieces of sandpaper or emery paper (gently!) will work (this is called scarifying). You may wish to look for seed which has already been treated in this manner, although not many companies do this.
Soaking: this can be of benefit in two ways. Besides softening the seed coat, it can also help to leach out chemicals present in the coat which could inhibit germination. Soak seed for 24 hours in water which begins at a temperature which is hot to the hand. As each seed swells up, remove and plant before it dries out.
Stratification (cold treatment): some seeds need a simulated winter to break dormancy. Use a tiny plastic bag with a small amount of dampened (not soaking!) sand. Add the seeds and place in refrigerator (not the freezer!) for the required amount of time. Check them from time to time to insure they don't dry out. Most seeds which require stratification also require light to germinate, so surface sow by just gently pressing the seed into the soil but make no attempt to cover with soil.
Double dormancy: Some seeds require more than one cold period or else a combination of conditions in which to break dormancy.
Extremely small seeds should be sown on the surface of a wet paper towel which is placed on a saucer or other flat dish. Cover the saucer with a food storage bag and twist tie the end to make a plastic tent. Don't put this in direct sunlight, but do put it in a bright spot. As the seeds begin to sprout, prick them off and plant. Or, you can place the potting medium into a plastic bag and sprinkle the seeds on the moist soil and twist tie the end of the bag. Cleaned meat trays from the market make good shallow containers for this too using either the paper towel or soil.
When to Plant
Hardy Annual (HA): From late winter to early spring Half Hardy Annual (HHA): Early to late spring - usually 4 to 8 weeks before planting outside. Perennial (P): Late winter to late spring Biennials (B): Late spring to early summer Hardy Shrub (Hsh): Winter to late spring and late summer to autumn Hardy tree (Ht): Winter to late spring and late summer to autumn Hardy Bulb (HBb): Late winter to late spring and late summer to autumn, but normally done in autumn Half Hardy Bulb (HHBb): Late winter to spring Greenhouse plants(Ghs): Can be started any time of year.
Medium and Temperature
For best results sow seeds in a sterile potting medium such as Pro-Mix and keeping evenly moist, but not saturated and do not allow to dry out. Best results will be obtained by ensuring that the temperature of the flat is the one noted here. If warmth is required you can place the flat on the cable box of the TV or on the top of the refrigerator, etc. where it will receive a gentle warmth. My personal preference is for the soil blocking method (a gizmo you can buy to make little soil blocks that are placed in a flat), but any method that works for you and that you're comfortable with is fine. As long as it produces, that's the goal. Once the seeds are sown they must be kept evenly moist. This is best accomplished under a cover of glass or plastic. Do not start your seeds in direct sunlight and especially with a glass or plastic covering as the heat of the sun will literally cook the seeds under the covering. Use a bright spot or start under lights where the temperature can be controlled.
Other Abbreviations Used
IS: In Situ; can be planted outside directly where it is to grow.
JC: Just Cover; barely cover with soil
SS:Surface Sow; press seeds gently into to the soil to make good contact, but do not cover with any additional soil; these seeds require light to germinate.
L/D: Light or Dark; seeds which require dark should have the flat covered with newspaper or brown paper or something similar to keep light from getting to the seeds.
S/I: Germination is slow and irregular
HH: Half hardy. If an annual, it will usually not reseed itself in northern zones, and if perennial, will be killed by freezing temperatures.
TP: Tender perennial (or shrub, etc). Will not winter over in northern zones, but makes a good greenhouse specimen.
BANANA; COFFEE; CYADS (and similar plants); MINI-ORANGE; PALMS; TEA: These plants are highly erratic in germination and can require several months. Seeds must be soaked for a minimum of 2 hours in warm water before sowing. Sow in compost especially designed for these plants and place in the dark at 75ºF. Keep compost moist at all times, but not wet. Check regularly and once in a while, dig around in the compost with a small knife or similar tool. Sow seeds just below the surface of the soil. Should a seed produce a root and no shoot, prick it out immediately and pot it in a 3 to 4" pot. It should produce a shoot then. When ready to be potted, Cycads prefer a planting medium of half sand and half peat. Tea requires the same treatment as the others but prefers a temperature of 60-65ºF. After soaking, remove the parchment-like on the coffee seeds with your fingernail before planting.
BEGONIA; BROMELIADS; CINERARIA; CALCEOLARIA; DROSERA; CHRISTMAS CACTUS; LIVING STONES; MECONOPSIS; NEPENTHES, RUBBER PLANTS; SAINTPAULIA; SARRACENIAS; STREPTOCARPUS; TIBOUCHINA: Surface sow on compost that is quite moist. Cover container with glass or clear plastic and place in diffuse light at temperature of 65ºF. When seeds begin to germinate, remove covering gradually. Seeds can also be spread on damp paper toweling or blotting paper and covered with plastic on windowsill which gets good light. Do NOT place in direct sunlight. Keep paper moist until seedlings are large enough to prick out and plant in small pots. For Drosera, Nepenthes, and Sarracenias make sure medium is both moist and free draining. Use NO fertilizer, but compost should contain some sphagnum moss.
ALSTROEMERIA; BONSAI; CLEMATIS; HARDY CYCLAMEN; EUCALYPTUS; HELLEBORUS; HOSTA; PRIMULA; IRIS: Between October and February, sow in compost and just barely cover. Place container in cold frame. Protect from predation by mice. Leave till spring. Keep medium moist but not wet. In spring bring containers into greenhouse or place on a well lit, but not sunny, windowsill. Keep moist. If seeds do not germinate, keep them in cool, moist conditions through summer and place back in cold frame in late fall. Once seeds do begin to germinate, remove them individually almost at once and set in pots.
An alternative method is to sow between March and September in a compost designed for these plants. Place the container in a plastic bag and place in refrigerator for 2 to 3 weeks. Remove and place in cold frame. If some should germinate, plant up when large enough to handle. The rest of the seeds will remain dormant until the following spring. Alstroemeria, Clematis, Hardy Cyclamen and Helleborus can take up to 18 months to germinate. Primulas can also be sown in a pre-moistened peat-based compost. The seeds should not be covered if using this method. Cover container with glass or plastic and place in the dark at 60ºF. If the temp goes over 65º, germination will not occur. Once seeds have begun to germinate, sprinkle a small bit of compost over them. When the leaves appear, move container to a place that is well lit (not direct sunlight) and has a temp of 55ºF.
CACTI: Sow in compost. Furrow should be very shallow and seeds must not be completely covered. Water from beneath. Cover container with glass, then a piece of dark paper (as from paper bag) or a piece of black plastic. Position in a dark place, maintaining a temperature of 70-75ºF. Keep moist. When germination commences, move to a position that receives indirect light (do not place in sun). Allow good air flow and continue watering from beneath. When seedlings begin to overcrowd the container, pot up. During the first winter season, make sure to keep plants warm, but do not allow to get too dry. From second year onward, keep on the dry side during the winter months.
CLIVIA (and similar plants): These seeds should be sown immediately upon receiving them. Sow in a peat-based compost to a depth of ½", then water and place in a dark environment at a temperature of 65-70ºF. Signs of germination should appear in 3 weeks.
FERNS: Fern spores require a fine film of moisture over which to move in order to complete the reproduction process. A good peat compost, pressed down firmly, must be used and kept a great deal more moist than normal. The spore should be sprinkled close together on the surface. Cover container with a piece of glass and move to a spot of diffused light. (Should not be in darkness). Compost must remain moist at all times. Germination begins with the appearance a film of green jelly on the soil surface. The process can take anywhere from 1 to 5 months before the plantlets appear.
LILIES: Some lily seeds require a double dormancy (a period of warmth followed by a period of cold). Sow seeds in a flat in summer. Place in a plastic bag and place in fridge for the winter, or cover with a piece of glass and set in cold frame. Seeds should germinate in spring. An alternative method is to place seeds in a jar with a ibt of peat kept moist, but not saturated. Screw lid on jar and place in a warm spot (70-75ºF) for 3 to 4 months. Check regularly. If any have sprouted, prick out and pot up. After the period of warmth, place in fridge for winter. The majority of the seeds that will germinate, will do so when returned to springlike warmth. Soil should be peaty and lime free with good drainage. Once bulbs are established, keep nearly dry during the winter months. Lilies resent being too wet.
BEAD PLANT: Use a good draining medium free of fertilizer. Equal parts moss, peat and sand makes a good medium. Barely cover the seed and cover with glass or clear plastic. Place container in temp of 65-75ºF. Since too much condensation can damage the young seedlings, be sure to lift glass or plastic and remove daily. When the first seedlings are spotted, remove cover and place in bright spot, but not in direct sunlight. Plant up seedlings as soon as possible in a mixture of ½ peat and ½ sand. Keep moist and in a shaded spot until well established.
STRELITZIA: Remove orange tuft and soak for a minimum of two hours up to overnight and as long as 3 days (change water daily). Sow seeds in moist sand, pressing them into the sand till only a small part is visible. Grow in a temperature of 75ºF in the dark and make sure the sand remains moist. After 7 days, inspect container once a week. As soon as signs of germination appear, remove the germinating seed and pot up in a medium composed of half peat and half sand. As soon as potted, make sure there is plenty of diffuse light and good ventilation to avoid fungal problems. Germination can occur as early as one week and as late as 6 months. Extremely irregular in habit.