Grape Seed information

Title: Grape Seed information
I sent the following information on germinating grape seeds to some people privately and they said I should post it.   Even though this is edited down from the final version, it is from the book I am preparing on grapes (out late 2000, with luck) and would appreciate it if you just keep it for your own use and don't spread it around.
-Lon Rombough
Grapes, unusual fruits, writing, more, at http://www.hevanet.com/lonrom
 Growing grapes from seed.
 The only way to get selected grapes to come true is to grow cuttings of them.  Plant seeds of, for example, Concord, and the odds of getting a seedling that is even similar to Concord are very small.  That's because most cultivated grapes contain such a mixture of genes that the seedlings get all sorts of different, new combinations of those genes.  So the only times grapes are grown from seed is when the grower is deliberately looking for seedlings that have new combinations of the parent traits, or when vines of pure species are being raised.  within a species, individual vines will resemble each other much more than any two seedlings out of a single cultivated variety, which is something plant collectors rely on when gathering material for breeding or botanical  collections.  But home growers can grow seedlings for other reasons, such as to be used as ornamentals.  Many American grape species not only have handsome, ornamental vines, flowers of most grapes are actually very sweet and fragrant.  Since nurseries don't regularly sell male grape vines, one of the few ways to get a male vine is to grow seed.  this is an advantage if there are native grape species in your area.  By using local species, you can find ones that are more accepting of local conditions and are apt to be able to resist pests and diseases in the area.   Breeding of grapes is covered in the chapter of that name, but basic seed techniques are noted here.
 When growing grapes from seed, the fresher the seed is, the better the rate of germination. If possible, use seed fresh from the fruit, cleaned, but not allowed to dry, and put directly into stratification in moist peat moss (see below). Seed which has become completely dry, especially if it has been stored that way for a long time, will usually produce fewer seedlings.
 If you are extracting seed from just a few berries and the grapes aren't too unpleasant to eat, carefully eating the grapes and cleaning the seeds with the mouth is a simple way.  With some species such as Vitis riparia, which have high acid, doing more than a few berries this way can make the mouth and tongue sore. In that case, it is better to cut the berries and remove the seeds with the point of a knife, or rub them through a coarse sieve to loosen the flesh, then float the flesh and skins off in water. If the seed has been freed from the flesh, the pulp and skins will float above them in the water. Fill the container with water and carefully pour off the pulp & skins. Repeat as needed until the seed is seen collected at the bottom of the container with no remaining pulp.
 Grape seed requires stratification - exposure to cold (but not freezing) temperatures in a moist environment - to break down the substances that keep the seeds dormant, before they will germinate.  If the seed is dry, start by soaking it in water for three days, with a change of water every day. This helps start the leaching out of some of the germination inhibitors and soaks up the dry seed. Next, mix the seed with moist peat moss, which not only holds the moisture needed for stratification, but has natural germicidal properties that help keep mold and rot off the seed.  On the rare occasions mold has appeared in seeds I have stratified, it has either been only surface mold, or the seed was hollow and non-viable to start with, so the mold did no harm either way. Only a small amount of peat is needed, no more than one or two tablespoons per hundred seeds, and it should be moist, but not soggy. It should be possible to squeeze only a small amount of water out of the moss, and then only by squeezing fairly hard.
 Put the mixture in a small plastic bag. Zip-lock types are easiest to use and can be labeled with a permanent pen. Store the seed at temperatures between 35 to 42oF for three months to stratify the seed. If the seed stays in stratification longer, it will not be harmed. Seed can be kept in refrigeration for up to a year with no ill effects.  Some grape species and certain varieties can germinate after as little as one month in stratification, but three months should cover the requirements of all species. In the days before refrigeration, it was common to plant seed either directly in the ground in the fall, or in pots or flats which could be stored in an unheated shed for the winter. If such a method is used, it is wise to protect the seed from rodents by covering the pots or flats with wire screen, as well as the outdoor seed rows.  In the latter case, bend the screen in a "U"shaped tube and press the ends into the soil to provide screen protection for the seed row and shelter for the emerging seedlings, as well.
 Once stratified, seed may be planted directly out in rows in the ground when soil is warm, or started much earlier, in flats or pots in a greenhouse. Again, use the screen described above to protect outdoor-planted seed from rodents and seedlings from slugs. Even with protection this method should just be used with mass-extracted seed where loss of some of the seedlings is not a problem. More valuable seeds, such as from controlled crosses, should be planted in pots or flats in a cold frame or greenhouse where they can be watched and protected more closely.
 Seeds of many grapes appear to respond to day length. In my work, even when temperatures are an ideal 68oF nighttime to 75oF to 80oF daytime, the greatest amount of germination may not start until the seeds get at least 15 to 15 1/2 hours of daylight, at least for temperate zone grapes.  Tropical species may respond differently. Supplemental light can be used to help augment germination early in the year before natural day length reaches 15 hours. Once the seedlings come up, they are less dependent on day length for their growth.
 Rate and speed of germination varies considerably with different species. Vitis rupestris, V.riparia, and V.longii (more recently known as V.acerifolia), and many hybrids with these species in their ancestry, will begin to germinate within two to three weeks, and most all the seed will germinate within a span of a week to two weeks at most, with very close to 100% of the seed sprouting. A number of the French Hybrids, which have V. rupestris and V. riparia in their ancestry, behave this way. Species such as V.labrusca and V.vinifera may take more than a month for the first seedling to emerge, with seedlings continuing to come up for a month or more, and as few as 30% of the total seeds sprouting. Many American varieties with V.labrusca in their parentage follow this pattern. However, with some of the species that are slow to germinate and have a low percentage of germination, much of the remaining seed will germinate if given a second stratification. Some growers have even found healthier, stronger plants in the second "crop" of seedlings than in the first, from the same batch of seed. More on this in the sections on breeding and grape species. In short, grape propagation is often easier, and certainly is no more difficult,  than any other fruit crop, though it may be necessary to use different methods than with other fruits.
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