One technique is to put the seeds on a sheet of sandpaper in a small container and then shake the container. Whichever method you use, the goal is to remove enough of the seed coat that water permeates the coat and causes the seed to germinate.
Too much or too little water is the most likely reason for seeds not germinating. With too little or no water, seeds remain dormant. With too much water, seeds become susceptible to rot or infection from soil-borne fungi (also referred to as "dampening off").
Some seeds like Allium 'Purple Sensation' and Eryngium giganteum need a long period of cold-moist stratification with alternating temperatures. These are the most difficult seeds to germinate.
Many seeds germinate much quicker in paper towels (versus seeds that are started in soil). The heat, moisture, and controlled conditions inside a plastic baggie help them germinate in only a few days (or less, depending on the seed).
Most of the seeds germinate best in dark environments. The presence of light tends to inhibit their growth. The light decomposes carbonic acid gas and expels oxygen which leads the seed to harden. These gases are key factors that promote germination.
The medium that is used to germinate seeds is a soilless mix. It's usually peat moss, vermiculite, perlite, or coir depending on who makes it. In any case, the advantages are the same: good drainage, light weight, and no surprise diseases.
All seeds need water, oxygen, and proper temperature in order to germinate. Some seeds require proper light also.
By soaking the seed, it enables the new growth from the inside to push through the hard shell and grow. The seeds that could benefit from a good soaking include: corn, pumpkin, beans, chard, beets, and peas. The seeds you shouldn't soak include: carrots, lettuce, radish, celery, turnips, and spinach.
Chives. Chives are a great herb to grow on your kitchen counter! They come up very quickly—it'll only take 2-3 days for chives to sprout. Additionally, they are quite happy at room temperature, just place it near a sunny window.
All seeds will be viable for one to two years. After two or three years, germination rates will drop for many types of seeds and will eventually fall to zero. So, stocking up on seeds for an “emergency” isn't a good idea because they don't last forever.
The broken seeds will not be able to grow into plants since they cannot mature or germinate. If the embryo of the seed gets damaged, it won't be able to provide nourishment to the young plant and there will be no chance of seed germination.
Extremes of heat or cold may prevent seeds from germinating so it's well worth monitoring the soil temperature with a soil thermometer. Most species can be sown successfully indoors at temperatures between 13C - 21C – easily achieved in a heated propagator or on a bright windowsill.
The truth is seeds don't expire. They lose viability if stored improperly. While most seed companies will tell you to replace seeds every 2-3 years, those seeds will keep for decades and will germinate when planted if kept in a cool, dark, and dry place.
Soak. Soaking the seeds even in plain water helps to saturate the embryo with moisture and to awaken it. Medium and large seeds are subject to soaking, small seeds are quickly saturated with moisture already in the ground. Use warm water for soaking.
Vinegar is an aqueous solution of acetic acid, which inhibits the process of seed germination. Higher concentration of acetic acid may destroy the seed vigor and inhibit the germination of seeds. Overall, vinegar can kill the seeds, the leaf, and possibly the entire plant.
For seeds to germinate, you need to keep the growing soil damp but not too wet. Learning how to water seedlings is pivotal for success. Many seed starters cover the container to keep soil moist until seeds germinate. Once seeds sprout, do not miss a watering.
Of all the factors that determine seed germination, water is the first and most important. Without water it cannot happen and a seed will stay dormant. But too much water and a seed will rot. Soil should be moist but not soaked.
One of the most popular ways to germinate seeds is the paper towel method.
There are four environmental factors that affect seed germination: Water, Light, Oxygen, and Heat.
Seeds need to be moderately moist to sprout. Seed germination is highly dependent on watering. Too dry and they won't get the message to sprout, too wet and they will rot in the dirt.
The fastest germinating seeds include everything in the cabbage family – bok choi, broccoli, kale, cauliflower etc, and lettuce. The slowest seeds to germinate are pepper, eggplant, fennel, celery, which may take 5+ days.
Distilled water is the best water for germinating seeds, sprouting, and plants of all kinds. One main reason why distilled water is preferred over tap water is that tap water contains salt, chlorine, and other chemicals that can build up in the plant's soil.