Seeds require a certain temperature in order to germinate. Each plant has a specific optimum and a range within which germination will occur. The closer the temperature is to optimum, the quicker germination will occur. Most seeds germinate when the soil temperature is between 68° and 86°F.
Temperature influences the moisture content, hormone function, and enzyme activity that occurs during seed germination. Warm temperatures accelerate the chemical reactions in seeds and accelerate cell formation for development.
Temperature affects germination in three primary ways: moisture, hormone production, and enzyme activity. For seeds to germinate, they need to imbibe water. For this to occur, sufficient moisture must be present. A warmer climate may increase evaporation and decrease moisture, which would negatively affect germination.
What is the optimum temperature when germinating seeds indoors? Answer: Most flower and vegetable seeds germinate best when the temperature of the germination medium (potting mix) is 70 to 75 degrees Fahrenheit.
Temperature is a critical environmental factor in seed germination [25,26]. The pace and rate of germination, which govern water absorption, may be affected by temperatures above or below the optimal range. Under optimal conditions, the absorption process is fast.
All seeds need water, oxygen, and proper temperature in order to germinate.
Seeds in the germination phase are especially sensitive to temperature. The temperature at which a seed germinates varies from plant to plant, but, in general, vegetable seeds germinate between 65 and 90° F (18 to 32° C), and most thrive between 75-85°F (24 to 30° C).
Vegetable seeds will germinate at a wide range of soil temperatures. Most seeds prefer to germinate in a range between 60 and 90 degrees. Some seeds are so sensitive to soil temps that they won't germinate if the soil is too hot or cold.
The best temperature to germinate most seeds is about 80°F (27°C). Many commonly-planted garden seeds will germinate in a week or two when the temperature is in an optimal range between approximately 65-85°F (18-29°C). Germination time and temperature varies between seed species and even cultivars.
Move the container to a warm, draft-free spot where you can check it daily. Most seeds germinate best when the temperature is between 65 and 70 degrees Fahrenheit, but check the information on the seed packet for specifics.
Pre-Soaking.
This method could be the fastest way to germinate seeds. Place seeds in a shallow container in warm water and leave them for 16 to 24 hours (smaller for 16, bigger for 24). Remember not to expose seeds to temperatures higher than 80°F (26.6°C) and not to pre-soak seeds for more than 24 hours.
By adding a little hydrogen peroxide to your water when you soak seeds, you're doing two things – breaking down the seed coat (chemical scarification) and oxygenating the water. Remember, oxygen was the second thing we needed for germination. Adding more oxygen to the water speeds up the germination process.
Key Factors in Germination
The three primary factors that regulate seed germination are moisture, temperature, and oxygen. Light is also an important influence on germination in some species. Moisture in adequate amounts, as stated above, is critical during germination and seedling growth.
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 majority of seeds grow most effectively in the dark. Light, which is essential for seedling growth, may actually hinder the germination process. The three primary and necessary conditions for a seed to germinate are water, oxygen, and temperature. Thus, Light is not necessary for a seed to germinate.
All seeds need warmth and moisture to germinate and grow on well. How much warmth varies by type of vegetable – for example broad beans will grow fine in soil temperatures over 8 degrees C, whereas aubergines need much more heat; ideally over 24C.
Most plants grow best in temperatures ranging from 59°–86°F. When temperatures above 90°F are sustained for long periods, plant growth is slowed, and some plants begin to show signs of stress.
Until seeds have sprouted, keep the seed bed moist, never allowing it to dry out. Water with a fine-spray hose nozzle or watering can which will provide a fine misty spray and not wash away the soil. Water often enough (usually about once a day) so that the soil surface never dries out, but remains constantly moist.
Hydrated seeds respond quite differently: high temperatures generally reinforce dormancy or may even induce it. Low temperatures may also induce dormancy in some circumstances, but in many species they are stimulatory (stratification response), especially within the range -1 degree C to 15 degrees C.
Seeds Germinated but Not Sprouting. Dry potting mix, incorrect growing temperatures, or various diseases can be the cause of seeds germinating but not sprouting.
The soil was too wet or too dry:
Too dry, and your seeds won't germinate. Too wet, and they're liable to rot. Ensure that seeds are kept evenly moist by thoroughly wetting and draining the compost before you begin.
Some seeds don't need light to break through their seed casings and sprout. Most seeds germinate best with controlled amounts of UV generation, but there are seeds that germinate in the absence of light. Furthermore, there are plants that get enough just light in highly shady areas of a garden or even in darkness.
There are four environmental factors that affect seed germination: Water, Light, Oxygen, and Heat. Check out these four tips to learn how much of each and when.
Germination depends on several environmental factors, e.g., water, oxygen, temperature, and often light and nitrate as well. Of these, water is the most essential factor.