Starting Grapes from Seed
Germinating Grape Seeds
Starting grapes from seeds can be a tad tricky, but it's not rocket science. Some of the more common problems encountered include in-viable Seeds, non fertile seeds and diseased and contaminated seed.
Non viable seeds are those that have not been properly stored or stored for way too long. They are generally only good for 1 or 2 seasons, sometimes 3, but beyond that your germination rate will be abysmal. Seeds can also be nonviable if they are not cold stratified. Cold stratifying mimics what the seeds would have experienced in nature during their dormant season, winter.
If you are using seed that you extracted from grapes yourself cold treating them is relatively simple.
Give the seeds a good washing to remove any pulp residue. I like to use extremely diluted bleach and water. Bleach is perfectly safe in small amounts and without added detergents. Dillution ratio is roughly 6 parts water to 1 part bleach which works out to about 3 cups of bleach per gallon of water. The small amount of bleach will destroy most contaminants without having any effect on the grape seed.
Soak the seeds for a full day before initiating the stratification process. DO NOT SOAK THEM IN THE BLEACH WATER, that was only for cleaning the seeds. Tap water will suffice but distilled water is best as it further reduces the chances of contamination and increases the odds in favor of germination..
Place the seeds in a moist paper towel, peat moss is better if you have it as it has anti-fungal properties, but a paper towel or coffee filter will suffice. Some people also use damp sand but it should sterile. Place the peat or towel in a zip lock bag and leave it in the fridge for about 2 months, a tad longer wouldn't hurt. Don't place it the freezer, just the refrigerator. Temperatures hovering around 35 F. or a little higher are best, temperatures below freezing are not advisable.
If you purchased your seeds from a reputable dealer they should already be cold stratified but there is still the chance that some are not viable. One simple way to weed out undesirable seeds is by dropping them in water. Any seeds that float to the top are hollow and will not germinate. Healthy viable seeds will sink to the bottom.
Come spring your seeds are ready to be planted. They can be started indoors in much the same fashion as other perennial garden seeds, but are best kept indoors till late spring or early summer. A greenhouse would be just dandy but not everybody has one, so a warm location will suffice. Once sprouts appear add sun light into the equation. Temperatures around 60 to 70 F are optimal during the germination process.
The germination period varies depending on the cultivar, seed quality and growing conditions but can take up to 2 months, if you're lucky on rare occasions fruition is achieved in a few weeks. You'll never get a 100% success rate, some seeds will not germinate but 75% or better is considered good.