Excerpted from lecture series by Amber Hearn (email@example.com)
Surprisingly, although most gardeners think nothing of raising vegetables from seed in the garden, or sowing a row of Marigolds or Zinnias, many of us do not even consider growing hardy plants or some of the other annuals, such as Petunias from seed. Many of these plants, however, are as easy to grow from seed as any of the ones commonly grown.
VEGETATIVE V. SEED
One of the main things to keep in mind when deciding to start seed of a particular plant is the end goal. There are two basic types of propagating. Vegetative and Seeds. Vegetative propagation is further broken down into different techniques such as divisions, cuttings, layering and cell culture. When propagating a plant we must first decide what method we should use to give the desired results. Vegetative propagation is a good choice if we desire plants that are identical to the parent as all vegetatively propagated plants are clones of their parents. If you desire more plants of a vegetatively propagated hybrid, the only true way to get them is by vegetative propagation. Sowing seeds on the other hand will produce progeny that may or may not be similar to the parent plant, especially if that plant is a vegetatively propagated hybrid or cultivar.
Plants are often cross-pollinated with other plants by insects or wind. This is of course mother-natures way of ensuring the diversity and health of any given species. This variation may be only slight and to all intents and purposes they may be identical to the parents, but it is still the progeny of two different plants and cannot be said to be the same plant, any more than children are the same as their parents. Once, when I was talking to someone about starting Hosta seeds, I told them that they shouldn't expect to get seedlings identical to the parent plants. I evidently wasn't very clear, because this poor confused person then asked me "Well if I won't get Hostas from the seed, what will I get?" So to clarify this, if the plant is a Hosta, all of the seedlings will still be Hostas, they just may not look identical to their parents. If you examine any species of plant in its natural habitat, you will see a great deal of diversity, whether in flower color, or size, leaf shape, height of plant etc. At first this variability may seem undesirable in the garden where you want more control of your plants, but if you are like me, you may rejoice in the diversity seed grown plants offer. If in the end, you are selective about keeping only the seed grown plants that demonstrate the properties you are looking for, you may end up with a good seed grown strain, or even better a great hybrid, good enough to market. At the least, you will end up with a garden full of wonderful healthy plants.
If you are propagating a true species, seeds often provide longer lived, sturdier plants than those grown vegetatively. The reason for this is twofold. If the plant that is used for vegetative propagation is diseased, this disease is transferred to the new plants. Many of the common diseases that affect garden plants are not, however, transferred to the seed. Secondly, the older a cultivar is, the harder it is to propagate, and the less vigorous the resulting plants will be. For example, if you propagate vegetatively from a plant that is seed grown, the progeny will probably be equally healthy and vigorous. Say you market the resulting plants. The plant is then propagated by the buyers. The resulting plants are slightly less vigorous than the originals. This downhill effect continues, until the results are weak and sickly, or won't propagate vegetatively at all. This is not always true, but it is something to keep in mind.
That said, you may also want to keep in mind that vegetative propagation will usually produce mature plants faster than seed. The Trillium for example can take over 7 years to flower from seed, but rhizome cuttings will produce a flowering plant in 2-3 years. In addition, there are many plants that simply cannot be propagated through the vegetative means available to the home gardener (tissue culture seems to work on most everything, but isn't practical unless you happen to have a laboratory next to your computer room). Your only other option, in these cases, is to either buy new plants to replace old ones, or grow them yourself from seed. It is hard to replace a plant if you can't find it available anymore. Experience will teach you better than any book or lecture which method is best and the only way to get that is to experiment yourself.
The Birth of a Seed: It is not absolutely necessary to know a little bit about the biology of seed to be able to grow plants from them. Any of us can throw seeds in the garden, or in a pot, and have fairly successful results without any in depth knowledge of the seed's inner workings, but a little basic knowledge never hurts. So, at the risk of boring you to tears, we're going to start with a seed biology refresher course. Although not all plants produce seed (ferns, mosses, liverworts, lichens and fungii do not) seed producing plants are the most complex and numerous forms of plants on the earth today. Seed producing plants are divided into two classifications.
Gymnosperms: (jim nuh spuhrmz) These include evergreens (conifers) like your Christmas tree and their relatives. The plants in this class produce cones, which hold and release their seed.
Angiosperms: (an jee uh spuhrmz)The more numerous of the two classes, includes all of the flowering plants, trees and shrubs in the world. In Angiosperms, the flower is the reproductive organ. It contains the reproductive organs that produce the seed. A flower may have either male or female organs, or both. Flowers with both are called perfect (tomatoes produce perfect flowers). Flowers with either one or the other are deemed imperfect. Hollies (Ilex species) produce imperfect flowers with male plants and female plants. Which is why you must have both to get those beautiful red berries. In flowering plants, once the female parts ( I won't bore you with the scientific names) are fertilized (pollinated) by the male sperm (pollen), a seed or seeds are formed. This usually takes place in the ovary of the female. The ovary then enlarges, and becomes the fruit of the plant. The fruit may be as complex as a peach, or as simple as a seed pod. This fruit is important in more than one way. First, it protects the seeds from damage until they are dispersed. Second, the makeup of the fruit often aids in dispersal of the seed. To be successful, a seed must germinate at a distance from the parent plant. The fruits are often designed to aid in this. Some taste good, are eaten, and the seeds passed at a distance from the plant. Some, like the Cocklebur, have protrusions which stick to the fur of animals. Some bear wings, such as the Maple fruit, to help the wind blow the seed away from the parent. And some, like the Touch-me-not, an Impatiens species, explode when the seed is ripe, scattering the seed for great distances.
Of most interest to us as we study seed starting, is the third function of the fruit. The fruit of many of the plants that produce seeds encased in fleshy fruit (Apples, peaches, grapes, walnuts, almonds, tomatoes etc.) also contains a germination inhibiting mechanism. This is usually a chemical, contained in the flesh of the fruit, that keeps the seed(s) inside from germinating before the appropriate time. This chemical is destroyed as the fruit rots, or is passed through an animals intestine. In seed starting, it is sometimes necessary for us to remove this germination inhibitor artificially. We'll talk more about that later.
The Structure of a Seed: The hard outer portion of the seed is known as the seed coat. The inside of the seed is called the embryo. The embryo consists of some basic structures. These are the hypocotyl (hy puh kaht uhl), which will eventually become the shoot or stem; the radicle (rad ih kuhl), which is the basis for the root of the plant, and the epicotyl (ep uh kaht uhl), the first true leaves. The seed also (usually) contains cotyledons (kaht uh lee duhnz). The cotyledons are the are the seed leaves. The first one or two little leaves that appear on a seedling. They are not true leaves, but are actually food storage organs.
A new seedling is not capable of producing it's own food. Food is stored in the cotyledons for the new plant to use until it is capable of photosynthesis. The seeds of some plants produce two cotyledons; these are named dicotyledonous (dy kaht uh lee duhn uhs), but are called dicots (dy kahts) for short. Tomatoes and beans are dicots. Other plants produce seeds which have only one cotyledon. These are named monocotyledonous (mahn uh kaht uh lee duhn uhs) or monocots (mahn uh kahts).
Corn, and most grasses, are monocots. Monocot seedlings also contain endosperm, which is another source of food for the seedling. This is not a complete explanation, as it gets more complicated that , but for our purposes in starting seeds, all we need is the basic knowledge that a radicle is the root, etc.
Dormancy?: After a seed is fully formed, it enters a period of inactivity, or dormancy. This dormant period is necessary before development into a plant can continue. If a seed did not go dormant after formation, it would germinate in the fruit or seed capsule right on the plant. This dormancy is caused by germination inhibitors. Usually (95% of the time) germination inhibitors are chemical in nature, but occasionally they are physical (such as seed coats that are impervious to water). During dormancy, the germination inhibitors are broken down, either chemically, or physically, or occasionally both. To be technically correct then, the seed is not actually dormant, or inactive, it is undergoing changes that break down the mechanisms that keep it from germinating. Since the word "Dormancy" is such an inaccurate term, I'm going to borrow a term from Norman C. Deno, a groundbreaking organic chemist who has dedicated his retirement to researching germination inhibitor mechanisms, and call this period "Conditioning".
Conditioning occurs naturally, over a period of time in nature, given the proper conditions. The amount of time, or the forces required to condition the seed vary with each species of plant. The trick to getting a seed to germinate then, is conditioning it so that it is ready to germinate. I'll talk more about seed conditioning in the next part of this lecture. For now, I would like to give credit and thanks to Mr. Norman C. Deno for his invaluable work on seed germination. His published work, "Seed Germination, Theory and Practice" has become a bible to me, and many other propagators of plant seed. Much of what I'm going to try to teach you is derived from this work.
There are several hundred commercial sources for the hobby gardener to obtain seeds of garden plants, vegetables, shrubs and trees. Since I'm limited in time, and space, I would like to suggest the following starting points:
Cindy Johnson's catalog of catalogs lists nearly 2000 mail order catalogs, both for plants and seeds, along with relevant information about the catalog.
"Gardening By Mail (A source book)" By Barbara J. Barton, published by Houghton Mifflin Books. Ms. Barton's book is a huge source of mail order businesses having to do with anything in the horticultural marketplace. You can find references for seeds, plants, bulbs, about any garden product, magazines, and addresses for garden clubs, societies and organizations. The information is indexed by product type and geographical location. Each entry gives a short description of the products available by the company, the catalog price, and more. When I bought my copy, it retailed for $18.95, but there has been a new edition published since then. Don't overlook the garden clubs and associations as a source for seeds. Often, they may be the only place you can find seeds of rare plants.
The North American Rock Garden Society, for example, publishes an annual seed exchange list to it's members, that contains nearly 6000 species of rare and unusual plants. Many of these seeds are collected by their members, or are made available by seed hunting expeditions to remote geographical locations. Membership information, and a copy of last years seedlist are available on line at the above link. You can not order seed unless you are a member of the society, but often the seeds are made available at such a discount to members that it pays for the membership fee. There are several such organizations, all with different specialties, that do the same thing. Most are listed in Barb's book, and a lot of them have a web page. Here are a couple that I've run across surfing:
The American Fern Society Homepage: -Has an annual spore exchange for members.
COLLECTING SEED: In your search for seed, don't overlook collecting from your own garden, and those of your friends. Many hardy garden plants, trees, shrubs, and even some vegetables set good seed crops that are available for the taking. Just don't collect seed of hybrids, unless you are just experimenting, as you never know what you're going to get. As we discussed previously, true species are the best candidates for seed as they will produce with little variation. It is a common misconception that the only time to collect seed is in the late summer and fall of the year. This is entirely untrue for many species. Each plant is designed to set seed within a fairly short period of time after it blooms and is pollinated. With plants that bloom in spring, you will usually find seed set by early summer.
Keep an eye on the target plants. After blooming, if pollination has been successful, they will begin to form fruit or seed pods. It is a matter of timing on your part to collect the seed before it has been released from the parent. When collecting seed, place each type, variety or species into a separate container such as a paper lunch bag, and label it with the name, date, and place of collection. Fruit seed will have to be cleaned when you get it home, and most seed that comes from a capsule or pod will need several days of drying before packaging.
FRUIT SEED: ( defined as any seed encased in a pulpy mass as opposed to a dry shell, including nuts that are surrounded by a fleshy coating). In the case of fruit seed, the seeds are mature when the fruit changes color. (Strawberries turn red, Blackberry Lilies turn purplish-black, Jack-in-the-Pulpits turn red, etc.) The thing to remember, that except for green apples, gooseberries and a few others, most fruits do not remain green when mature. Collect the seed, when the fruit is ripe, then remove the seeds from the fruit. This is necessary to remove chemical germination inhibitors that may be present in the flesh of the fruit. It was once believed, that fruit seed didn't germinate easily because the seed coats were impervious to water, but this theory has been disproved by Norm Deno, and others working in the field. Deno's research has shown that in actuality, there is usually a water channel in the seed coat that allows the inhibitors in the flesh to continually reach the seed, preventing it from germinating. If a fruit sits around long enough in storage, all the chemical is used up, and the seed will germinate inside. If the flesh is removed, and the seed itself contains no further blocking mechanism, the fruit will germinate within days. Unfortunately for the grower, there are often additional inhibitors contained within the seed itself that continue to prohibit germination until they are used up or destroyed. These are most often destroyed by cold storage, which we'll discuss a little later. With large one-seeded fruits, removing the seeds is fairly easy. With fruits such as strawberries, kiwi, or tomatoes, the seeds are well attached to the fruit, are also tiny, and are difficult to remove. In these cases, I use the following method to help separate the seed. First mash the fruit. Large seeds can be removed and wiped off on a paper towel. Small seeded fruits are pushed through a strainer or sieve. Next place the whole mess into a container, add water to cover, and stir. The pulp and the seed will begin to separate. The seeds may or may not float. Another common myth is that only good seeds will sink, but this is not necessarily true. It is however, easier when they sink because you can dump off the water and pulp, and end up with fairly clean seeds at the bottom. If they float, wait until the water settles and, using a spoon or other implement, dip the seeds off of the water surface. You may have to repeat this process several times to effectively remove most of the pulp.
In the case of tomatoes, kiwi, and other seeds with a gelatinous coating, the following is recommended. Place the seeds and as little pulp as possible in a container. Add just enough water to cover. Let the seeds set for a few of days, stirring daily. The pulp will begin to ferment and rot away, allowing the seeds to sink. When most of the seeds are loose, pour off the top and rinse the seeds in fresh water. Some growers also wash the seed in a grease removing dish detergent to further remove any oils that may contain germination inhibitors. I hate to name product names, but Joy is an excellent choice for this. I've never heard it expressed elsewhere, but Lemon Joy contains some citric acid, which may help break down the stubborn oils attached to the seed coat. In fact, with some varieties, a daily soaking in fresh water for a week or more, may be necessary to remove germination inhibitors. I like to add a few drops of fresh lemon juice to the water to help clean the seeds, after an initial cleaning with detergent. (Some experts use solutions of sulfuric acid to treat seed before sowing for the same purpose, but most acid is a dangerous thing to keep around the house, if you can even obtain a supply) Do not leave the seeds soaking in water, but rinse them thoroughly, and store them in a damp paper towel in a plastic baggy between rinsings. Rinse until the seeds feel clean and smooth, and don't leave your hands feeling oily.
Before sowing, it is a good idea to cut open a seed or two to make sure there is living material inside. Many plants produce a lot of seeds with empty seed coats. In general, if the seed material is plump, firm and white or cream in color, the seeds are probably viable. With most fruit seeds, allowing them to dry between the rinsing and sowing process is not a good idea, as this seems to either kill them, or send them into a deep dormancy. (There are exceptions, primarily fruit from annual plants, such as tomatoes, squash and watermelon.) Fruit from trees, vines, shrubs and perennials often needs a cold conditioning period after the rinsing process. I use Norm Deno's paper towel method for this. Simply take a heavy duty white paper towel, folded in half three times, labeled with the variety and date, and dampened. Open the towels up two folds, then place the seeds inside. Fold the towel bag up, place in a loose polyethylene baggy, and place in the refrigerator. Open them up every couple of weeks to allow some extra air to circulate around the seeds, but otherwise leave them alone for a period of 3 months. When the three months are up, move the bags to room temperature, and check them about once a week.
If germination doesn't begin within a two to three month period, it is likely that a second cold period is necessary. Repeat the process until germination begins. There are other methods of dealing with fruit seed. Nurseries that produce in quantity, simply macerate the fruit, pack it in damp sand, pulp and all, cover with an inch of sand, water well and place in the shade in the coldest spot they can find, and let mother nature go to work. When germination begins the seeds are then sown into seed beds or pots. This process is fine, but it is neither as fast, or as effective for the home gardener. I prefer the paper towel method, because I can get two cold and two warm periods in the space of a year, and I don't have to wait for the fruit to rot away. A combination of the two methods may work well too. The important thing to remember, is that not all seeds will germinate in one year, some take two or more, so don't throw seeds away until you are certain they are not viable. I can't count the times I've given up to early and tossed the seeds into the compost pile only to have seedlings show up there the following spring.
In summary, the following is recommended for collected fruit seeds. 1. Remove the seeds from the fruit pulp as soon as possible after collection, using one of the methods we discussed, or one of your own making. 2. Clean the seeds thoroughly in clear water to remove the remaining pulp that clings to the seeds. It is OK to use a little elbow grease, or even a scouring pad on larger seeds. 3. Give any seeds that have the slightest oily feel left to them a gentle scrubbing with a grease removing detergent. a) It is a good idea to continue rinsing the seed daily in fresh water for at least one week. (I add a little lemon juice to the water). Some seeds benefit from a longer rinsing cycle. The exception to this rule is the seeds encased in a gelatin like substance or the seeds of annual vegetables. If you continue to rinse seeds of this type, germination may begin prematurely. b) In general, at this point, if the seed is from an annual or tropical plant, you may either sow the seeds at room temperature immediately, or spread them out, allow them to dry, and store them until you are ready to sow them. 4. Again, as a general rule of thumb, place the seeds of temperate zone plants into cold storage for, at least, 3 months (90 days), and then move them to room temp. (about 70F). If germination does not occur within that period, repeat the cold and warm cycles until it does.
For purchased fruit seeds, or seeds that have been dry stored, assuming that the pulp has already been removed, (this isn't always the case, I've received seeds that has been stored in dried fruit) begin with step 3 above and treat like fresh seed. Seed that has been dry stored may not be viable, or may take a lot longer to germinate than fresh seed. This is not a hard and fast rule, but before you waste your time, it might be a good idea to open a couple and check them for life signs.
Keep in mind that these are only general guidelines. They won't work for everything. If they fail, try something else. We'll discuss some other germination tricks in a bit. I use these methods because I'm an impatient propagator. I want to see quick results. Remember that each species has evolved it's own methods of survival and germination of it's seed. You can always throw the seeds in a pot, set it outdoors, and hope for the best.
SEEDS FROM PODS/CAPSULES: (This very general category, includes any of the many seeds that are not encased in a fleshy fruit, but in a thin walled, usually dry and papery capsule or pod.) Unfortunately, the rules are even less specific with these type of seeds. I hope I don't totally confuse you, but I'll try and give some basic guidelines for collecting, storing and germinating these seeds. First of all, collect them when the pods begin to open. This indicates that they are ripe. Second, clean as much excess material (chaff) from the seeds as possible before sowing or storing. Disposition and storage are another matter.
As you may have surmised from our talk on fruit seed, how a seed is dealt with after collection is quite important. Some seeds in this category do not tolerate being dry stored any more than many of the fruit seeds, and if they are, they may die, or go into deep dormancy. And this time I do mean the word dormancy. Conversely, there are other seeds that will not germinate well unless they are dry stored for a period of time before sowing. Yet others have impervious seed coats that must be corrupted before water can enter and germination begin.
There are some that germinate immediately if sown in warmth. There are some that germinate in cold temperatures only. There are some that germinate in warmth, but need a cold period first. And there are some that need a warm period followed by a cold period. There are even quite a few that need warm day temperatures and cool nights to condition them. And if that isn't enough, some require light, and a few need darkness. And you thought fruit seed was complicated *Grin*. So if you don't know which is which, how do you figure it out? I will not pretend to have all the answers. I can, in fact, guarantee you I do not, and not even an expert like Norman Deno does, although his books are of tremendous benefit here. But there is always an answer, and the answer can be usually be determined by observing the plants natural habits, or using the information that you have or can find about a purchased or traded seed to make an educated guess. If you have the plant, note when it sets seed. This will give you some clues.
I divide the seeds into three basic categories, those to sow immediately, those that need to be dried out before sowing, and those that have impervious seed coats. Here are some basic guidelines to get you started.
SEEDS THAT SHOULD BE SOWN IMMEDIATELY: Many plants can be sown immediately, but seeds of these plants will be difficult and on rare occasions impossible to germinate if they are not. Spring ephemera's is the first type falling into this category. These are normally woodland or understory perennials, often bulbs, that put up foliage very early in the spring, and bloom before the average air temperature hits 70F. Many of the seeds of these plants need to be sown fresh, or alternatively stored in a moist cool environment until time to sow them. If seed of these plants is allowed to dry out before sowing, germination may take 3 or 4 times as long, and some few may never germinate. After cleaning these seeds, I wrap them in a moist paper towel, place them in a baggy, and store them at room temperature until early fall when they are sown into seedling pans and placed out of doors in a cold frame. Many of them will germinate with the onset of cool nights and warm days. Others germinate the following spring.
Alternatively, you could place the seeds in your refrigerator each evening, and germinate them in the towels. Some examples of these plants are Trillium species, Dicentra (Bleeding Hearts and Dutchman's Breeches), Delphinium tricorne (Wild Larkspur), Corydalis species (Fumitory), Sanguinaria canadensis (Bloodroot), and Eranthis (Winter Aconite).
The other seeds that fall into this category are those woodland species that set seed in early to late fall. Often these seeds fall to the ground and germinate immediately. The tiny seedlings then overwinter in the ground, and begin growing with the onset of warm weather. The classic examples of these plants are Aconitum (Wolf's Bane), Cyclamen, and late blooming Helleborus sp. (Christmas Rose) and Arisaema species (these can also be considered a fruit). I place these seeds immediately into seedling pans, and follow the cool night, warm day pattern that is used for the spring species. You may of course also sow them into towels.
Sometimes, the only way to obtain these plants is to buy seed. If you obtain seed of one of these plants that has been dry stored, sow them into towels in the refrigerator, and alternate cold and warm cycles until germination begins. I find it helpful to start with a cold cycle, then after 3 months remove the seeds from the refrigerator every second day and allow them to come to room temperature. They are then returned to the refrigerator. This is of course to imitate the warming up cycle in spring. I keep this up for about a month, leaving the seeds out for increasingly longer periods of time. If germination doesn't begin within 3 months after the seeds are kept constantly at room temperature, try giving them another cold treatment. I use this treatment though for just about all of my seeds that I sow in the refrigerator, not just the ephemera's.
SEEDS THAT NEED TO BE DRY STORED BEFORE SOWING: Many, many seeds respond well to being dried out before sowing. The theory is that either they don't have mature embryos when they leave the plant, or that there are chemical inhibitors that break down as the seed ages. According to Norm Deno, with these seeds, there is an optimum storage time. Seeds sown fresh often won't germinate at all, but if they are stored for a few months, they will germinate easily. If they are kept in storage too long, they will eventually use up all their stored food and die. Norm suggests that they be stored for approximately 6 months, but I never really pay much attention to storage time. I collect seeds as they are ripe, dry them by leaving them in thin layers in a old butter carton, then clean, package and store them until I'm ready to sow. If I collected them in early summer they probably do get six months storage, but any later and I'm sure they get less. This general rule applies to nearly all of the popular sun-loving garden plants and grasses. For clues, look at the plant. Does it hold it's pods upright, or retain it's seeds for a long time after the capsules are open? If so, it probably will respond favorably to dry storage. The seed of all the common garden vegetables, most herbs, and probably 90% of the annual flowers fall into this category.
Dry stored seed is usually dried for a week or so in the open air. I've heard some people recommend that you leave them out the sun, but I don't. I simply spread them out in thin layers and allow them to air dry in a room with good air circulation. They are then cleaned and packaged into paper envelopes (properly labeled and dated of course) and placed in a seed collection box. If I have leftover seed after I get done sowing the seed in winter, or early spring, the remainder are moved to cold storage, to maintain as much viability as possible. I place the packets in ziploc bags and put them in the refrigerator. Do not try to force all of the air out of the bag, as the seeds need to have air, and the air will keep you from crushing them with a milk carton.
Now do I sow them at room temperature, or do I start them in the refrigerator? By far, the largest number of popular garden plants can be started easily in warmth. There is, however, no easy way to tell which ones need a cold period. If I simply have no idea, I try to make a guess as to the time of the year the plant sets seeds (assuming I don't know). If it sets seed early on in the late spring or summer, it is probable that the seed won't be harmed by warm temps, and will probably germinate in warmth, so I start them at 70F. If the plant sets seed later on, it is likely that either the plant needs a cold period first, or will at least not germinate readily at room temperature. Sometimes it can be harmful to sow seeds warm. If the plant's seeds would not fall on warm soil in nature, don't try starting them that way. Try the cold period first. In general, if I don't know, and the seed is valuable I always start with a cold period. You are less likely to kill the seed this way.
IMPERVIOUS SEED COATS: These are most often found in seeds of the pea family (Fabacaea), but may be found elsewhere on occasion, especially in plants that evolved on prairies where they would be subjected to annual fires. These seeds are usually dry stored prior to sowing, but it doesn't really seem to matter. On the whole, these seeds are longer lived than most of the other types. I've germinated seeds of the Golden Chain tree (Laburnum) that; were 12 years old.
Usually, the only trick to germinating this type of seed is to corrupt the seed coat enough so that water can get in, without tearing up the seed. (There are a couple of exceptions, one is Opuntia, and the other Leucocrinum, both natives of the Western US, there maybe others as well. These seeds also need a cold treatment.) With large seeds, like morning glories, it is a simple procedure to clip off a piece of the seed coat with a pair of nail clippers, or make a small pinprick with an exacto knife. Smaller seeds can be rubbed against some sandpaper glued to a board. Both of these methods will work, although I don't use the sandpaper one. The seeds are often too damaged to live. If you dampen a towel and then sprinkle the seeds you've treated in it and hold for a couple of hours, the ones that are ready to absorb water will begin to swell. Here are a couple of other tips. I haven't tried all of them.
1. Tie the seeds up in a stocking and place them in running water (a dripping faucet) for several days. When they start to swell up, plant them.
2. Soak them in a cola product until the coats are softened. I've not tried this one, just read about it the other day.
3. Place them in a small jar with some sandblasting (silica) sand, and shake them vigorously, or put the whole mix in a rock tumbler without the water and tumble for an hour. This one I've tried, and it is great for really small seeds like Astragalus and Sphaeralcea.
4. Rub the seeds against a whetting stone instead of sandpaper. You are less likely to damage them than if you use sandpaper.
5. Pour almost boiling water over them, and let stand overnight before sowing.
GENERAL SOWING INSTRUCTIONS: I use two different methods for sowing seed, either paper towels or seedling pots (commonly referred to as pans).
PAPER TOWEL METHOD: I got this method from Norm Deno, who says he got it from someone else. This is very easy. Take white paper towels. Fold them in half three times. Label the towel with the variety, date and any other information, like oscillate temps before bringing to warmth. Dampen the towels, squeezing out most of the water. It should be well dampened, but you shouldn't be able to squeeze more than a couple of drops out of it. Open the towel open two folds. Sow the seeds inside. Fold back up, and place in a thin, non-ziploc bag.
Whether you are placing them in the fridge, or not, you need to open them up at least once a week to check for germination and allow air to circulate around the seeds briefly. When germination begins, I move the germinated seeds with tweezers to a seedling pot. If I know the variety well enough to predict it's behavior, I don't wait for more than one or two seedlings to germinate before moving them all to pots. Some seeds, with erratic germination, have to be moved as they germinate. These are the main ones I sow in towels. If you sow seeds with erratic germination in pots, the ones that germinate first will crowd out the later ones, and if you try to prick them out one at a time, you may end up burying the others. I also sow very rare and valuable seeds into towels, as overall there is a better success rate. The only other ones I sow in towels are those needing alternating cycles of warmth and cold. Germination is faster this way.
You can place several towels into each bag, although you should be careful to place seeds that actually need light to germinate in bags by themselves. (There actually aren't very many that do. Most of the ones that light is recommended for actually don't require it, but are very small and just shouldn't be sown too deep or they won't be able to break the surface). Make sure you do not put the bags in the sun, as they will overheat. I place mine on the end of the same shelf the seedling pots are on. Norm Deno uses a separate method for seeds that require light to germinate, sowing the seeds on top of the towels. I don't, I've found that they get plenty of light to germinate through a white paper towel. If the towels begin to break down, or get really moldy, just transfer the seeds to a clean towel. You will often have a little mold growing on the towel, or internally infected seeds. Remove the bad seeds, but don't worry too much about the mold growing on the towel. After three years experience with this method, I can say for certain that I've only had one case of seeds being killed by the mold in a towel, and that was some I left in the fridge over the busy spring season without remembering to ever check them.
Lastly, use this method of sowing only if it's necessary, or you have the time to transplant the sprouted seeds. It is a time consuming process. And don't use this method on dust like seeds. You can never get them loose from the towels as the ultra fine radicles root immediately to the towel.
SEEDLING POTS: Even with a nursery, I still only use seedling pots. If the variety is very popular, I might sow two or three, but rarely do I need them all. I use a sterile soil mix for the medium, mixed with 1/4 to 1/2 part coarse grit or perlite. Rock garden plants get more grit. The pots are cleaned in hot water and filled full to the rim. I then dampen the pots with a fine spray from the hose. (Some people use a boiling water bath to insure sterility). The seeds are sown directly on to the surface of the soil. I do not make little holes for each one. Most professional propagators don't. We'd never get finished. The seeds are then covered with granite grit. Rarely more than 1/4", and just a very fine layer over seeds that are small or need light. Place a plastic label in the pot, or use a folder label, and stick one to the pot. Put the pots either out of doors in a cold frame, or indoors under lights. I don't use my greenhouse for starting because it tends to overheat, but if you have one that has fairly even temperatures, you could. Indoors, I mist the surface of the pots daily with a fine mister, and water about twice a month. You'll soon be able to tell which ones need water just by the weight of the pot when you lift it. Keep the seed pots evenly moist, but not constantly soaked. Sprouted seeds moved to pots from the towels are treated the same way. There is no need to go about making a tiny hole for each radicle. Just lay them on the soil. They'll find the way down.
I do not feed seedlings in seedling pots. When the seedlings are big enough, they are moved to individual pots, or seedling flats. Transplant them before they become over crowded. I don't wait very long. Usually if they are big enough for me to hold on to, and have the first set of true leaves, I move them. I begin feeding a mild organic fertilizer after they are established in their new homes. You'll have to make your own choices there. I have no suggestions as far as chemical fertilizers are concerned. I don't use them.
Above all when beginning don't expect everything to work like clockwork. Don't give up. If at first you don't succeed with a particular variety, try it again next year. I get better at it every year. You will too.